%global _empty_manifest_terminate_build 0 Name: python-watiba Version: 0.6.59 Release: 1 Summary: Python syntactical sugar for embedded shell commands License: MIT URL: https://github.com/Raythonic/watiba Source0: https://mirrors.nju.edu.cn/pypi/web/packages/74/42/84b3fa7e253b186eca318ed809307624cca7b095901dc5ea741263e83934/watiba-0.6.59.tar.gz BuildArch: noarch %description # Watiba #### Version: **0.6.59** #### Date: 2021/12/04 Watiba, pronounced wah-TEE-bah, is a lightweight Python pre-compiler for embedding Linux shell commands within Python applications. It is similar to other languages' syntactical enhancements where XML or HTML is integrated into a language such as JavaScript. That is the concept applied here but integrating BASH shell commands with Python. As you browse this document, you'll find Watiba is rich with features for shell command integration with Python. Features: - Shell command integration with Python code - In-line access to shell command results - Current directory context maintained across commands throughout your Python code - Async/promise support for integrated shell commands - Remote shell command execution - Remote shell command chaining and piping ## Table of Contents 1. [Usage](#usage) 2. [Directory Context](#directory-context) 3. [Commands as Variables](#commands-as-variables) 4. [Command Results](#command-results) 5. [Asynchronous Spawning and Promises](#async-spawing-and-promises) 1. [Useful Properties in Promise](#useful-properties-in-promise) 2. [Spawn Controller](#spawn-controller) 3. [Join, Wait or Watch](#join-wait-watch) 4. [The Promise Tree](#promise-tree) 5. [Threads](#threads) 6. [Remote Execution](#remote-execution) 1. [Change SSH port for remote execution](#change-ssh-port) 7. [Command Hooks](#command-hooks) 8. [Command Chaining](#command-chaining) 9. [Command Chain Piping (Experimental)](#piping-output) 10. [Installation](#installation) 11. [Pre-compiling](#pre-compiling) 12. [Code Examples](#code-examples)
## Usage Watiba files, suffixed with ".wt", are Python programs containing embedded shell commands. Shell commands are expressed within backtick characters emulating BASH's original capture syntax. They can be placed in any Python statement or expression. Watiba keeps track of the current working directory after the execution of any shell command so that all subsequent shell commands keep context. For example: Basic example of embedded commands: ``` #!/usr/bin/python3 # Typical Python program if __name__ == "__main__": # Change directory context `cd /tmp` # Directory context maintained for file in `ls -lrt`.stdout: # In-line access to command results print(f"File in /tmp: {file}") ``` This loop will display the file list from /tmp. The `ls -lrt` is run in the context of previous `cd /tmp`.
#### Commands Expressed as Variables Commands within backticks can _be_ a variable, but cannot contain snippets of Python code or Python variables. The statement within the backticks _must_ be either a pure shell command or a Python variable containing a pure shell command. To execute commands in a Python variable, prefix the variable name between backticks with a dollar sign. _A command variable is denoted by prepending a dollar sign on the variable name within backticks_: ``` # Set the Python variable to the command cmdA = 'echo "This is a line of output" > /tmp/blah.txt' cmdB = 'cat /tmp/blah.txt' # Execute first command `$cmdA` # Execute the command within Python variable cmdA # Execute second command for line in `$cmdB`.stdout: print(line) ``` _This example demonstrates keeping dir context and executing a command by variable_: ``` #!/usr/bin/python3 if __name__ == "__main__": # Change CWD to /tmp `cd /tmp` # Set a command string my_cmd = "tar -zxvf tmp.tar.gz" # Execute that command and save the command results in variable "w" w = `$my_cmd` if w.exit_code == 0: for l in w.stderr: print(l) ``` _These constructs are **not** supported_: ``` file_name = "blah.txt" # Python variable within backticks `touch file_name` # NOT SUPPORTED! # Attempting to access Python variable with dollar sign `touch $file_name` # NOT SUPPORTED! # Python within backticks is NOT SUPPORTED! `if x not in l: ls -lrt x` ```
## Directory Context An important Watiba usage point is directory context is kept for dispersed shell commands. Any command that changes the shell's CWD is discovered and kept by Watiba. Watiba achieves this by tagging a `&& echo pwd` to the user's command, locating the result in the command's STDOUT, and finally setting the Python environment to that CWD with `os.chdir(dir)`. This is automatic and opaque to the user. The user will not see the results of the generated suffix. If the `echo` suffix presents a problem for the user, it can be eliminated by prefixing the leading backtick with a dash. The dash turns off the context tracking by not suffixing the command and so causes Watiba to lose its context. However, the context is maintained _within_ the set of commands in the backticks just not when it returns. For example, **out = -\`cd /tmp && ls -lrt\`** honors the ```cd``` within the scope of that execution line, but not for any backticked commands that follow later in your code. **_Warning!_** The dash will cause Watiba to lose its directory context should the command cause a CWD change either explicitly or implicitly. _Example_: ``` `cd /tmp` # Context will be kept # This will print from /home/user, but context is NOT kept for line in -`cd /home/user && ls -lrt`.stdout: print(line) # This will print from /tmp, not /home/user for line in `ls -lrt`.stdout: print(line) ```
## Command Results The results of the command issued in backticks are available in the properties of the object returned by Watiba. Following are those properties:
PropertyData TypeDescription
stdoutListSTDOUT lines from the command normalized for display
stderrListSTDERR lines from the command normalized for display
exit_codeIntegerExit code value from command
cwdStringCurrent working directory after command was executed
Technically, the returned object for any shell command is defined in the WTOutput class.
## Asynchronous Spawning and Promises Shell commands can be executed asynchronously with a defined resolver callback block. Each _spawn_ expression creates and runs a new OS thread. The resolver is a callback block that follows the Watiba _spawn_ expression. The spawn feature is executed when a ```spawn `cmd` args: resolver block``` code block is encountered. The resolver is passed the results in the promise object. (The promise structure contains the properties defined in section ["Results from Spawned Commands"](#spawn-results) The _spawn_ expression also returns a _promise_ object to the caller of _spawn_. The promise object is passed to the _resolver block_ in argument _promise_. The outer code can check its state with a call to _resolved()_ on the *returned* promise object. Output from the command is found in _promise.output_. The examples throughout this README and in the _examples.wt_ file make this clear.
##### Useful properties in promise structure A promise is either returned in assignment from outermost spawn, or passed to child spawns in argument "promise".
Property Data Type Description
hostStringHost name on which spawned command ran
childrenListChildren promises for this promise node
parentReferenceParent promise node of child promise. None if root promise.
commandStringShell command issued for this promise
resolved()MethodCall to find out if this promise is resolved
resolve_parent()MethodCall inside resolver block to resolve parent promise
tree_dump()MethodCall to show the promise tree. Takes subtree argument otherwise it defaults to the root promise
join()MethodCall to wait on on promise and all its children
wait()MethodCall to wait on just this promise
watch()MethodCall to create watcher on this promise
start_timeTimeTime that spawned command started
end_timeTimeTime that promise resolved
_Example of simple spawn_: ```buildoutcfg prom = spawn `tar -zcvf big_file.tar.gz some_dir/*`: # Resolver block to which "promise" and "args" is passed... print(f"{promise.command} completed.") return True # Resolve promise # Do other things while tar is running # Finally wait for tar promise to resolve prom.join() ```
#### Spawn Controller All spawned threads are managed by Watiba's Spawn Controller. The controller watches for too many threads and incrementally slows down each thread start when that threshold is exceeded until either all the promises in the tree resolve, or an expiration count is reached, at which time an exception is thrown on the last spawned command. This exception is raised by the default error method. This method as well as other spawn controlling parameters can be overridden. The controller's purpose is to not allow run away threads and provide signaling of possible hung threads. _spawn-ctl_ example: ```buildoutcfg # Only allow 20 spawns max, # and increase slowdown by 1/2 second each 3rd cycle ...python code... spawn-ctl {"max":20, "sleep-increment":.500} ``` Spawn control parameters:
Key Name Data Type Description Default
maxIntegerThe maximum number of spawned commands allowed before the controller enters slowdown mode10
sleep-floorIntegerSeconds of starting sleep value when the controller enters slowdown mode.125 (start at 1/8th second pause)
sleep-incrementIntegerSeconds the amount of seconds sleep will increase every 3rd cycle when in slowdown mode.125 (Increase pause 1/8th second every 3rd cycle)
sleep-ceilingIntegerSeconds the highest length sleep value allowed when in slowdown mode (As slow as it will get)3 (won't get slower than 3 second pauses)
expireIntegerTotal number of slowdown cycles allowed before the error method is calledNo expiration
errorMethod Callback method invoked when slowdown mode expires. Use this to catch hung commands. This method is passed 2 arguments: - **promise** - The promise attempting execution at the time of expiration - **count** - The thread count (unresolved promises) at the time of expiration Generic error handler. Just throws WTSpawnException that hold properties promise and message
**_spawn-ctl_** only overrides the values it sets and does not affect values not specified. _spawn-ctl_ statements can set whichever values it wants, can be dispersed throughout your code (i.e. multiple _spawn-ctl_ statements) and only affects subsequent spawn expressions. _Notes:_ 1. Arguments can be passed to the resolver by specifying a trailing variable after the command. If the arguments variable is omitted, an empty dictionary, i.e. {}, is passed to the resolver in _args_. **_Warning!_** Python threading does not deep copy objects passed as arguments to threads. What you place in ```args``` of the spawn expression will only be shallow copied so if there are references to other objects, it's not likely to survive the copy. 2. The resolver must return _True_ to set the promise to resolved, or _False_ to leave it unresolved. 3. A resolver can also set the promise to resolved by calling ```promise.set_resolved()```. This is handy in cases where a resolver has spawned another command and doesn't want the outer promise resolved until the inner resolvers are done. To resolve an outer, i.e. parent, resolver issue _promise.resolve_parent()_. Then the parent resolver can return _False_ at the end of its block so it leaves the resolved determination to the inner resolver block. 4. Each promise object holds its OS thread object in property _thread_ and its thread id in property _thread_id_. This can be useful for controlling the thread directly. For example, to signal a kill. 5. _spawn-ctl_ has no affect on _join_, _wait_, or _watch_. This is because _spawn-ctl_ establishes an upper end throttle on the overall spawning process. When the number of spawns hits the max value, throttling (i.e. slowdown mode) takes affect and will expire if none of the promises resolve. Conversely, the arguments used by _join_, _wait_ and _watch_ control the sleep cycle and expiration of just those calls, not the spawned threads as a whole. When an expiration is set for, say, _join_, then that join will expire at that time. When an expiration is set in _spawn-ctl_, then if all the spawned threads as a whole don't resolve in time then an expiration function is called. **_Spawn Syntax:_** ``` my_promise = spawn `cmd` [args]: resolver block (promise, args) args passed in args return resolved or unresolved (True or False) ``` _Spawn with resolver arguments omitted_: ``` my_promise = spawn `cmd`: resolver block (promise, args) return resolved or unresolved (True or False) ``` _Simple spawn example_: ```buildoutcfg p = spawn `tar -zcvf /tmp/file.tar.gz /home/user/dir`: # Resolver block to which "promise" and "args" are passed # Resolver block is called when spawned command has completed for line in promise.output.stderr: print(line) # This marks the promise resolved return True # Wait for spawned command to resolve (not merely complete) try: p.join({"expire": 3}) print("tar resolved") except Exception as ex: print(ex.args) ``` _Example of file that overrides spawn controller parameters_: ``` #!/usr/bin/python3 def spawn_expired(promise, count): print("I do nothing just to demonstrate the error callback.") print(f"This command failed {promise.command} at this threshold {count}") raise Exception("Too many threads.") if __name__ == "__main__": # Example showing default values parms = {"max": 10, # Max number of threads allowed before slowdown mode "sleep-floor": .125, # Starting sleep value "sleep-ceiling": 3, # Maximum sleep value "sleep-increment": .125, # Incremental sleep value "expire": -1, # Default: no expiration "error": spawn_expired # Method called upon slowdown expiration } # Set spawn controller parameter values spawn-ctl parms ```
#### Join, Wait, or Watch Once commands are spawned, the caller can wait for _all_ promises, including inner or child promises, to complete, or the caller can wait for just a specific promise to complete. To wait for all _child_ promises including the promise on which you're calling this method, call _join()_. It will wait for that promise and all its children. To wait for just one specific promise, call _wait()_ on the promise of interest. To wait for _all_ promises in the promise tree, call _join()_ on the root promise. _join_ and _wait_ can be controlled through parameters. Each are iterators paused with a sleep method and will throw an expiration exception should you set a limit for iterations. If an expiration value is not set, no exception will be thrown and the cycle will run only until the promise(s) are resolved. _join_ and _wait_ are not affected by _spawn-ctl_. _watch_ is called to establish a separate asynchronous thread that will call back a function of your choosing should the command the promise is attached to time out. This is different than _join_ and _wait_ in that _watch_ is not synchronous and does not pause. This is used to keep an eye on a spawned command and take action should it hang. Your watcher function is passed the promise on which the watcher was attached, and the arguments, if any, from the spawn expression. If your command does not time out (i.e. hangs and expires), the watcher thread will quietly go away when the promise is resolved. _watch_ expiration is expressed in **seconds**, unlike _join_ and _wait_ which are expressed as total _iterations_ paused at the sleep value. _watch_'s polling cycle pause is .250 seconds, so the expiration value is multiplied by 4. The default expiration is 15 seconds. Examples: ``` # Spawn a thread running this command p = spawn `ls -lrt`: ## resolver block ## return True # Wait for promises, pause for 1/4 second each iteration, and throw an exception after 4 iterations (1 second) try: p.join({"sleep": .250, "expire": 4}) except Exception as ex: print(ex.args) # Wait for this promise, pause for 1 second each iteration, and throw an exception after 5 iterations (5 seconds) try: p.wait({"sleep": 1, "expire": 5}) except Exception as ex: print(ex.args) # My watcher function (called if spawned command never resolves by its experation period) def watcher(promise, args): print(f"This promise is likely hung: {promise.command}") print(f"and I still have the spawn expression's args: {args}") p = spawn `echo "hello" && sleep 5` args: print(f"Args passed to me: {args}") return True # Attach a watcher to this thread. It will be called upon experation. p.watch(watcher) print("watch() does not pause like join or wait") # Attach a watcher that will expire in 5 seconds p.watch(watcher, {"expire": 5}) ``` **_join_ syntax** ``` promise.join({optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of joining parent and children promises_: ``` p = spawn `ls *.txt`: for f in promise.output.stdout: cmd = f"tar -zcvf {f}.tar.gz {f}" spawn `$cmd` {"file":f}: print(f"{f} completed") promise.resolve_parent() return True return False # Wait for all commands to complete try: p.join({"sleep":1, "expire":20}) except Exception as ex: print(ex.args) ``` **_wait_ syntax** ``` promise.wait({optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of waiting on just the parent promise_: ``` p = spawn `ls *.txt`: for f in promise.output.stdout: cmd = f"tar -zcvf {f}.tar.gz {}" spawn `$cmd` {"file":f}: print(f"{f} completed") promise.resolve_parent() # Wait completes here return True return False # Wait for just the parent promise to complete try: p.wait({"sleep":1, "expire":20}) except Exception as ex: print(ex.args) ``` **_watch_ syntax** ``` promise.watch(callback, {optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of creating a watcher_: ```buildoutcfg # Define watcher method. Called if command times out (i.e. expires) def time_out(promise, args): print(f"Command {promise.command} timed out.") # Spawn a thread running some command that hangs p = spawn `long-running.sh`: print("Finally completed. Watcher method won't be called.") return True p.watch(time_out) # Does not wait. Calls method "time_out" if this promise expires (i.e. command hangs) # Do other things... ```
#### The Promise Tree Each _spawn_ issued inserts its promise object into the promise tree. The outermost _spawn_ will generate the root promise and each inner _spawn_ will be among its children. There's no limit to how far it can nest. _wait_ only applies to the promise on which it is called and is how it is different than _join_. _wait_ does not consider any other promise state but the one it's called for, whereas _join_ considers the one it's called for **and** anything below it in the tree. The promise tree can be printed with the ```dump_tree()``` method on the promise. This method is intended for diagnostic purposes where it must be determined why spawned commands hung. ```dump_tree(subtree)``` accepts a subtree promise as an argument. If no arguments are passed, ```dump_tree()``` dumps from the root promise on down. ``` # Simple example with no child promises p = spawn `date`: return True p.tree_dump() # Dump tree from root # or p.tree_dump(subtree_promise) # Dump tree from node in argument ``` Example dumping tree from subtree node: ```buildoutcfg # Complex example with child and grandchild promises # Demonstrates how to dump the promise tree from various points within it p = spawn `date`: # Spawn child command (child promise) spawn `pwd`: # Spawn a grandchild to the parent promise spawn `python --version`: promise.tree_dump(promise) # Dump the subtree from this point down return False # Spawn another child spawn `echo "blah"`: # Resolve parent promise promise.resolve_parent() # Resolve child promise return True # Do NOT resolve parent promise, let child do that return False p.join() p.tree_dump(p.children[0]) # Dump subtree from first child on down p.tree_dump(p.children[1]) # Dump subtree from the second child p.tree_dump(p.children[0].children[0]) # Dump subtree from the grandchild # Dump all children for c in p.children: p.tree_dump(c) ``` _Parent and child joins shown in these two examples_: ``` root_promise = spawn `ls -lr`: for file in promise.stdout: t = f"touch {file}" spawn `$t` {"file" file}: # This promise is a child of root print(f"{file} updated".) spawn `echo "done" > /tmp/done"`: # Another child promise (root's grandchild) print("Complete") promise.resolve_parent() return True promise.resolve_parent() return False return False root_promise.join() # Wait on the root promise and all its children. Thus, waiting for everything. ``` ``` root_promise = spawn `ls -lr`: for file in promise.output.stdout: t = f"touch {file}" spawn `$t` {"file" file}: # This promise is a child of root print(f"{promise.args['file'])} updated") promise.join() # Wait for this promise and its children but not its parent (root) spawn `echo "done" > /tmp/done"`: print("Complete") ``` _Resolving a parent promise_: ``` p = spawn `ls -lrt`: for f in promise.output.stdout: cmd = f"touch {f}" # Spawn command from this resolver and pass our promise spawn `$cmd`: print("Resolving all promises") promise.resolve_parent() # Resolve parent promise here return True # Resolve child promise return False # Do NOT resolve parent promise here p.join() # Wait for ALL promises to be resolved ```
### Results from Spawned Commands Spawned commands return their results in the _promise.output_ property of the _promise_ object passed to the resolver block, and in the spawn expression if there is an assignment in that spawn expression. The result properties can then be accessed as followed:
PropertyData TypeDescription
promise.output.stdoutListSTDOUT lines from the command normalized for display
promise.output.stderrListSTDERR lines from the command normalized for display
promise.output.exit_codeIntegerExit code value from command
promise.output.cwdStringCurrent working directory after command was executed
_Notes:_ 1. Watiba backticked commands can exist within the resolver 2. Other _spawn_ blocks can be embedded within a resolver (recursion allowed) 3. The command within the _spawn_ definition can be a variable (The same rules apply as for all backticked shell commands. This means the variable must contain pure shell commands.) 4. The leading dash to ignore CWD _cannot_ be used in the _spawn_ expression 5. The _promise.output_ object is not available until _promise.resolved()_ returns True _Simple example with the shell command as a Python variable_: ``` #!/usr/bin/python3 # run "date" command asynchronously d = 'date "+%Y/%m/%d"' spawn `$d`: print(promise.output.stdout[0]) return True ``` _Example with shell commands executed within resolver block_: ``` #!/usr/bin/python3 print("Running Watiba spawn with wait") `rm /tmp/done` # run "ls -lrt" command asynchronously p = spawn `ls -lrt`: print(f"Exit code: {promise.output.exit_code}") print(f"CWD: {promise.output.cwd}") print(f"STDERR: {promise.output.stderr}") # Loop through STDOUT from command for l in promise.output.stdout: print(l) `echo "Done" > /tmp/done` # Resolve promise return True # Pause until spawn command is complete p.wait() print("complete") ```
### Threads Each promise produced from a _spawn_ expression results in one OS thread. To access the number of threads your code has spawned collectively, you can do the following: ``` num_of_spawns = promise.spawn_count() # Returns number of nodes in the promise tree num_of_resolved_promises = promise.resolved_count() # Returns the number of promises resolved in tree ```
## Remote Execution Shell commands can be executed remotely. This is achieved though the SSH command, issued by Watiba, and has the following requirements: - OpenSSH is installed on the local and remote hosts - The local SSH key is in the remote's _authorized_keys_ file. _The details of this process is beyond the scope of this README. For those instructions, consult www.ssh.com_ - Make sure that SSH'ing to the target host does not cause any prompts. Test that your SSH environment is setup first by manually entering: ``` ssh {user}@{host} "ls -lrt" # For example ssh rwalk@walkubu "ls -lrt" # If SSH prompts you, then Watiba remote execution cannot function. ``` To execute a command remotely, a _@host_ parameter is suffixed to the backticked command. The host name can be a literal or a variable. To employ a variable, prepend a _$_ to the name following _@_ such as _@$var_.
#### Change SSH port for remote execution To change the default SSH port 22 to a custom value, add to your Watiba code: ```watiba-ctl {"ssh-port": custom port}``` Example: ```buildoutcfg watiba-ctl {"ssh-port": 2233} ``` Examples: ```buildoutcfg p = spawn `ls -lrt`@remoteserver {parms}: for line in promise.output.stdout: print(line) return True ``` ```buildoutcfg remotename = "serverB" p = spawn `ls -lrt`@$remotename {parms}: for line in p.output.stdout: print(line) return True ``` ```buildoutcfg out = `ls -lrt`@remoteserver for line in out.stdout: print(line) ``` ```buildoutcfg remotename = "serverB" out = `ls -lrt`@$remotename for line in out.stdout: print(line) ```
## Command Hooks Hooks are pre- or -post functions that are attached to a _command_ _pattern_, which is a regular expression (regex). Anytime Watiba encounters a command that matches the pattern for the hook, the hook function is called. All commands, spawned, remote, or local, can have Python functions executed **before** exection, by default, or **post hooks** that are run **after** the command. (Note: Post hooks are not run for spwaned commands because the resolver function is a post hook itself.) These functions can be passed arguments, too. ### Command Hook Expressions ``` # Run before commands that match that pattern hook-cmd "pattern" hook-function parms # Run before commands that match that pattern, but is non-recursive hook-cmd-nr "pattern" hook-function parms # Run after commands that match that pattern post-hook-cmd "pattern" hook-function parms # Run after commands that match that pattern, but is non-recursive post-hook-cmd-nr "pattern" hook-function parms ``` ### Hook Recursion Hooks, which are nothing more than Python functions called before or after a command is run, can issue their own commands and, thus, cause the hook to be recursively called. However, if the command in the hook block of code matches a command pattern that causes that same hook function to be run again, an infinte loop can occur. To prevent that, use the **-nr** suffix on the Watiba hook expression. (-nr stands for non-recursive.) This will ensure that the hook cannot be re-invoked for any commands that are within it.
To attach a hook: 1. Code one or more Python functions that will be the hooks. At the end of each hook, you must return True if the hook was successful, or False if something wrong. 2. Use the _hook-cmd_ expression to attach those hooks to a command pattern, which is a regular expression 3. To remove the hooks, use the _remove-hooks "pattern"_ expression. If a pattern, i.e. command regex pattern, is omitted, then all command hooks are removed. **hook-cmd "command pattern" function parms** The first parameter always passed to the hook function is the Python _match_ object from the command match. This is provided so the hook has access to the tokens on the command should it need them. Example: ``` def my_hook(match, parms): print(match.groups()) print(f'Tar file name is {match.group(1)}') print(parms["parmA"]) print(parms["parmB"]) return True # Successful execution def your_hook(match, parms): # This hook doesn't need the match object, so ignores it print(parms["something"]) if parms["something-else"] != "blah": return False # Failed execution return True # Successful excution # Add first hook to my tar command hook-cmd "tar -zcvf (\S.*)" my_hook: {"parmA":"A", "parmB":"B"} # Add another hook to my tar command hook-cmd "tar -zcvf (\S.*)" your_hook: {"parmD":1, "parmE":"something"} # Spawn command, but hooks will be invoked first... spawn `tar -zcvf files.tar.gz /tmp/files/* `: # Resolver code block return True # Resolve promise ``` Your parameters are whatever is valid for Python. These are simply passed to their attached functions, essentially each one's key is the function name, as specified. _Where are the hooks run for spawned commands?_ All hooks run under the thread of the issuer on the local host, not the target thread. _Where are the hooks run for remote commands?_ As with spawned commands, all hooks are issued on the local host, not the remote. Note that you can have remote backticked commands in your hook and that will run those remotely. If your remote command matches a hook(s) pattern, then those hooks will be run. This means if your command pattern for the first remote call runs a hook that contains another remote command that matches that same command pattern, then the hook is run again. Since this can lead to infinte hook loops, Watiba offers a non-recursive definition for the command pattern. Note that this non-recursive setting only applies to the command pattern and not the hook function itself. So if _hookA_ is run for two different command patterns, say, "ls -lrt" and "ls -laF" you can make one non-recusrive and still run the same hook for both commands. For the recursive command pattern, the hook has no limit to its recursion. For non-recursive, it will only be called once during the recursion process. To set a command pattern as non-recursive, use _hook-cmd-nr_. Example using a variation on a previous example: ``` def my_hook(match, parms) `tar -zcvf /tmp/files` # my_hook will NOT because for this command even though it matches print("Will be called only once!") return True # Note the "-nr" on the expression. That's for non-recursive hook-cmd-nr "tar -zcvf (\S.*)" my_hook: {"parmA":"A", "parmB":"B"} # my_hook will be called before this command runs ` tar -zcvf tarball.tar.gz /home/user/files.*` ```
## Command Chaining Watiba extends its remote command execution to chaining commands across multiple remote hosts. This is achieved by the _chain_ expression. This expression will execute the backticked command across a list of hosts, passed by the user, sequentially, synchronously until the hosts list is exhausted, or the command fails. _chain_ returns a Python dictionary where the keys are the host names and the values the WTOutput from the command run on that host. #### Chain Exception The _chain_ expression raises a WTChainException on the first failed command. The exception raised has the following properties: _WTChainException_:
PropertyData TypeDescription
commandStringCommand that failed
hostStringHost where command failed
messageStringError message
outputWTOutput structure: - stdout - stderr - exit_code - cwdOutput from command
Import this exception to catch it: ```buildoutcfg from watiba import WTChainException ``` Examples: ``` from watiba import WTChainException try: out = chain `tar -zcvf backup/file.tar.gz dir/*` {"hosts", ["serverA", "serverB"]} for host,output in out.items(): print(f'{host} exit code: {output.exit_code}') for line in output.stderr: print(line) except WTChainException(ex): print(f"Error: {ex.message}") print(f" host: {ex.host} exit code: {ex.output.exit_code} command: {ex.command}) ```
## Command Chain Piping (Experimental) The _chain_ expression supports piping STDOUT and/or STDERR to other commands executed on remote servers. Complex arrangements can be constructed through the Python dictionary passed to the _chain_ expression. The dictionary contents function as follows: - "hosts": [server, server, ...] This entry instructions _chain_ on which hosts the backticked command will run. This is a required entry. - "stdout": {server:command, server:command, ...} This is an optional entry. - "stderr": {server:command, server:command, ...} This is an optional entry. Just like a _chain_ expression that does not pipe output, the return object is a dictionary of WTOutput object keyed by the host name from the _hosts_ list and *not* from the commands recieving the piped output. If any command fails, a WTChainException is raised. Import this exception to catch it: ```buildoutcfg from watiba import WTChainException ``` _Note_: _The piping feature is experimental as of this release, and a better design will eventually supercede it._ Examples: ``` from watiba import WTChainException # This is a simple chain with no piping try: args = {"hosts": ["serverA", "serverB", "serverC"]} out = chain `ls -lrt dir/` args for host, output in out.items(): print(f'{host} exit code: {output.exit_code}') except WTChainException as ex: print(f'ERROR: {ex.message}, {ex.host}, {ex.command}, {ex.output.stderr}') ``` ``` # This is a more complex chain that runs the "ls -lrt" command on each server listed in "hosts" # and pipes the STDOUT output from serverC to serverV and serverD, to those commands, and serverB's STDERR # to serverX and its command try: args = {"hosts": ["serverA", "serverB", "serverC"], "stdout": {"serverC":{"serverV": "grep something", "serverD":"grep somethingelse"}}, "stderr": {"serverB":{"serverX": "cat >> /tmp/serverC.err"}} } out = chain `ls -lrt dir/` args for host, output in out.items(): print(f'{host} exit code: {output.exit_code}') except WTChainException as ex: print(f'ERROR: {ex.message}, {ex.host}, {ex.command}, {ex.output.stderr}') ``` ####How does this work? Watiba will run the backticked command in the expression on each host listed in _hosts_, in sequence and synchronously. If there is a "stdout" found in the arguments, then it will name the source host as the key, i.e. the host from which STDOUT will be read, and fed to each host and command listed under that host. This is true for STDERR as well. The method in which Watiba feeds the piped output is through a an _echo_ command shell piped to the command to be run on that host. So, "stdout": {"serverC":{"serverV": "grep something"}} causes Watiba to read each line of STDOUT from serverC and issue ```echo "$line" | grep something``` on serverV. It is piping from serverC to serverV.
## Installation ### PIP If you installed this as a Python package, e.g. pip, then the pre-compiler, _watiba-c_, will be placed in your system's PATH by PIP. ### GITHUB If you cloned this from github, you'll still need to install the package with pip, first, for the watbia module. Follow these steps to install Watiba locally. ``` # Watiba package required python3 -m pip install watiba ```
## Pre-compiling Test that the pre-compiler functions in your environment: ``` watiba-c version ``` For example: ```buildoutcfg rwalk@walkubu:~$ watiba-c version Watiba 0.3.26 ``` To pre-compile a .wt file: ``` watiba-c my_file.wt > my_file.py chmod +x my_file.py ./my_file.py ``` Where _my_file.wt_ is your Watiba code.
## Code Examples **my_file.wt** ``` #!/usr/bin/python3 # Stand alone commands. One with directory context, one without # This CWD will be active until a subsequent command changes it `cd /tmp` # Simple statement utilizing command and results in one statement print(`cd /tmp`.cwd) # This will not change the Watiba CWD context, because of the dash prefix, but within # the command itself the cd is honored. file.txt is created in /home/user/blah but # this does not impact the CWD of any subsequent commands. They # are still operating from the previous cd command to /tmp -`cd /home/user/blah && touch file.txt` # This will print "/tmp" _not_ /home because of the leading dash on the command print(f"CWD is not /home: {-`cd /home`.cwd)}" # This will find text files in /tmp/, not /home/user/blah (CWD context!) w=`find . -name '*.txt'` for l in w.stdout: print(f"File: {l}") # Embedding commands in print expressions that will print the stderr output, which tar writes to print(`echo "Some textual comment" > /tmp/blah.txt && tar -zcvf /tmp/blah.tar.gz /tmp`).stdout) # This will print the first line of stdout from the echo print(`echo "hello!"`.stdout[0]) # Example of more than one command in a statement line if len(`ls -lrt`.stdout) > 0 or len(-`cd /tmp`.stdout) > 0: print("You have stdout or stderr messages") # Example of a command as a Python varible and # receiving a Watiba object cmd = "tar -zcvf /tmp/watiba_test.tar.gz /mnt/data/git/watiba/src" cmd_results = `$cmd` if cmd_results.exit_code == 0: for l in cmd_results.stderr: print(l) # Simple reading of command output # Iterate on the stdout property for l in `cat blah.txt`.stdout: print(l) # Example of a failed command to see its exit code xc = `lsvv -lrt`.exit_code print(f"Return code: {xc}") # Example of running a command asynchronously and resolving promise spawn `cd /tmp && tar -zxvf tarball.tar.gz`: for l in promise.output.stderr: print(l) return True # Mark promise resolved # List dirs from CWD, iterate through them, spawn a tar command # then within the resolver, spawn a move command # Demonstrates spawns within resolvers for dir in `ls -d *`.stdout: tar = "tar -zcvf {}.tar.gz {}" prom = spawn `$tar` {"dir": dir}: print(f"{}args['dir'] tar complete") mv = f"mv -r {args['dir']}/* /tmp/." spawn `$mv`: print("Move done") # Resolve outer promise promise.resolve_parent() return True # Do not resolve this promise yet. Let the inner resolver do it return False prom.join() ``` %package -n python3-watiba Summary: Python syntactical sugar for embedded shell commands Provides: python-watiba BuildRequires: python3-devel BuildRequires: python3-setuptools BuildRequires: python3-pip %description -n python3-watiba # Watiba #### Version: **0.6.59** #### Date: 2021/12/04 Watiba, pronounced wah-TEE-bah, is a lightweight Python pre-compiler for embedding Linux shell commands within Python applications. It is similar to other languages' syntactical enhancements where XML or HTML is integrated into a language such as JavaScript. That is the concept applied here but integrating BASH shell commands with Python. As you browse this document, you'll find Watiba is rich with features for shell command integration with Python. Features: - Shell command integration with Python code - In-line access to shell command results - Current directory context maintained across commands throughout your Python code - Async/promise support for integrated shell commands - Remote shell command execution - Remote shell command chaining and piping ## Table of Contents 1. [Usage](#usage) 2. [Directory Context](#directory-context) 3. [Commands as Variables](#commands-as-variables) 4. [Command Results](#command-results) 5. [Asynchronous Spawning and Promises](#async-spawing-and-promises) 1. [Useful Properties in Promise](#useful-properties-in-promise) 2. [Spawn Controller](#spawn-controller) 3. [Join, Wait or Watch](#join-wait-watch) 4. [The Promise Tree](#promise-tree) 5. [Threads](#threads) 6. [Remote Execution](#remote-execution) 1. [Change SSH port for remote execution](#change-ssh-port) 7. [Command Hooks](#command-hooks) 8. [Command Chaining](#command-chaining) 9. [Command Chain Piping (Experimental)](#piping-output) 10. [Installation](#installation) 11. [Pre-compiling](#pre-compiling) 12. [Code Examples](#code-examples)
## Usage Watiba files, suffixed with ".wt", are Python programs containing embedded shell commands. Shell commands are expressed within backtick characters emulating BASH's original capture syntax. They can be placed in any Python statement or expression. Watiba keeps track of the current working directory after the execution of any shell command so that all subsequent shell commands keep context. For example: Basic example of embedded commands: ``` #!/usr/bin/python3 # Typical Python program if __name__ == "__main__": # Change directory context `cd /tmp` # Directory context maintained for file in `ls -lrt`.stdout: # In-line access to command results print(f"File in /tmp: {file}") ``` This loop will display the file list from /tmp. The `ls -lrt` is run in the context of previous `cd /tmp`.
#### Commands Expressed as Variables Commands within backticks can _be_ a variable, but cannot contain snippets of Python code or Python variables. The statement within the backticks _must_ be either a pure shell command or a Python variable containing a pure shell command. To execute commands in a Python variable, prefix the variable name between backticks with a dollar sign. _A command variable is denoted by prepending a dollar sign on the variable name within backticks_: ``` # Set the Python variable to the command cmdA = 'echo "This is a line of output" > /tmp/blah.txt' cmdB = 'cat /tmp/blah.txt' # Execute first command `$cmdA` # Execute the command within Python variable cmdA # Execute second command for line in `$cmdB`.stdout: print(line) ``` _This example demonstrates keeping dir context and executing a command by variable_: ``` #!/usr/bin/python3 if __name__ == "__main__": # Change CWD to /tmp `cd /tmp` # Set a command string my_cmd = "tar -zxvf tmp.tar.gz" # Execute that command and save the command results in variable "w" w = `$my_cmd` if w.exit_code == 0: for l in w.stderr: print(l) ``` _These constructs are **not** supported_: ``` file_name = "blah.txt" # Python variable within backticks `touch file_name` # NOT SUPPORTED! # Attempting to access Python variable with dollar sign `touch $file_name` # NOT SUPPORTED! # Python within backticks is NOT SUPPORTED! `if x not in l: ls -lrt x` ```
## Directory Context An important Watiba usage point is directory context is kept for dispersed shell commands. Any command that changes the shell's CWD is discovered and kept by Watiba. Watiba achieves this by tagging a `&& echo pwd` to the user's command, locating the result in the command's STDOUT, and finally setting the Python environment to that CWD with `os.chdir(dir)`. This is automatic and opaque to the user. The user will not see the results of the generated suffix. If the `echo` suffix presents a problem for the user, it can be eliminated by prefixing the leading backtick with a dash. The dash turns off the context tracking by not suffixing the command and so causes Watiba to lose its context. However, the context is maintained _within_ the set of commands in the backticks just not when it returns. For example, **out = -\`cd /tmp && ls -lrt\`** honors the ```cd``` within the scope of that execution line, but not for any backticked commands that follow later in your code. **_Warning!_** The dash will cause Watiba to lose its directory context should the command cause a CWD change either explicitly or implicitly. _Example_: ``` `cd /tmp` # Context will be kept # This will print from /home/user, but context is NOT kept for line in -`cd /home/user && ls -lrt`.stdout: print(line) # This will print from /tmp, not /home/user for line in `ls -lrt`.stdout: print(line) ```
## Command Results The results of the command issued in backticks are available in the properties of the object returned by Watiba. Following are those properties:
PropertyData TypeDescription
stdoutListSTDOUT lines from the command normalized for display
stderrListSTDERR lines from the command normalized for display
exit_codeIntegerExit code value from command
cwdStringCurrent working directory after command was executed
Technically, the returned object for any shell command is defined in the WTOutput class.
## Asynchronous Spawning and Promises Shell commands can be executed asynchronously with a defined resolver callback block. Each _spawn_ expression creates and runs a new OS thread. The resolver is a callback block that follows the Watiba _spawn_ expression. The spawn feature is executed when a ```spawn `cmd` args: resolver block``` code block is encountered. The resolver is passed the results in the promise object. (The promise structure contains the properties defined in section ["Results from Spawned Commands"](#spawn-results) The _spawn_ expression also returns a _promise_ object to the caller of _spawn_. The promise object is passed to the _resolver block_ in argument _promise_. The outer code can check its state with a call to _resolved()_ on the *returned* promise object. Output from the command is found in _promise.output_. The examples throughout this README and in the _examples.wt_ file make this clear.
##### Useful properties in promise structure A promise is either returned in assignment from outermost spawn, or passed to child spawns in argument "promise".
Property Data Type Description
hostStringHost name on which spawned command ran
childrenListChildren promises for this promise node
parentReferenceParent promise node of child promise. None if root promise.
commandStringShell command issued for this promise
resolved()MethodCall to find out if this promise is resolved
resolve_parent()MethodCall inside resolver block to resolve parent promise
tree_dump()MethodCall to show the promise tree. Takes subtree argument otherwise it defaults to the root promise
join()MethodCall to wait on on promise and all its children
wait()MethodCall to wait on just this promise
watch()MethodCall to create watcher on this promise
start_timeTimeTime that spawned command started
end_timeTimeTime that promise resolved
_Example of simple spawn_: ```buildoutcfg prom = spawn `tar -zcvf big_file.tar.gz some_dir/*`: # Resolver block to which "promise" and "args" is passed... print(f"{promise.command} completed.") return True # Resolve promise # Do other things while tar is running # Finally wait for tar promise to resolve prom.join() ```
#### Spawn Controller All spawned threads are managed by Watiba's Spawn Controller. The controller watches for too many threads and incrementally slows down each thread start when that threshold is exceeded until either all the promises in the tree resolve, or an expiration count is reached, at which time an exception is thrown on the last spawned command. This exception is raised by the default error method. This method as well as other spawn controlling parameters can be overridden. The controller's purpose is to not allow run away threads and provide signaling of possible hung threads. _spawn-ctl_ example: ```buildoutcfg # Only allow 20 spawns max, # and increase slowdown by 1/2 second each 3rd cycle ...python code... spawn-ctl {"max":20, "sleep-increment":.500} ``` Spawn control parameters:
Key Name Data Type Description Default
maxIntegerThe maximum number of spawned commands allowed before the controller enters slowdown mode10
sleep-floorIntegerSeconds of starting sleep value when the controller enters slowdown mode.125 (start at 1/8th second pause)
sleep-incrementIntegerSeconds the amount of seconds sleep will increase every 3rd cycle when in slowdown mode.125 (Increase pause 1/8th second every 3rd cycle)
sleep-ceilingIntegerSeconds the highest length sleep value allowed when in slowdown mode (As slow as it will get)3 (won't get slower than 3 second pauses)
expireIntegerTotal number of slowdown cycles allowed before the error method is calledNo expiration
errorMethod Callback method invoked when slowdown mode expires. Use this to catch hung commands. This method is passed 2 arguments: - **promise** - The promise attempting execution at the time of expiration - **count** - The thread count (unresolved promises) at the time of expiration Generic error handler. Just throws WTSpawnException that hold properties promise and message
**_spawn-ctl_** only overrides the values it sets and does not affect values not specified. _spawn-ctl_ statements can set whichever values it wants, can be dispersed throughout your code (i.e. multiple _spawn-ctl_ statements) and only affects subsequent spawn expressions. _Notes:_ 1. Arguments can be passed to the resolver by specifying a trailing variable after the command. If the arguments variable is omitted, an empty dictionary, i.e. {}, is passed to the resolver in _args_. **_Warning!_** Python threading does not deep copy objects passed as arguments to threads. What you place in ```args``` of the spawn expression will only be shallow copied so if there are references to other objects, it's not likely to survive the copy. 2. The resolver must return _True_ to set the promise to resolved, or _False_ to leave it unresolved. 3. A resolver can also set the promise to resolved by calling ```promise.set_resolved()```. This is handy in cases where a resolver has spawned another command and doesn't want the outer promise resolved until the inner resolvers are done. To resolve an outer, i.e. parent, resolver issue _promise.resolve_parent()_. Then the parent resolver can return _False_ at the end of its block so it leaves the resolved determination to the inner resolver block. 4. Each promise object holds its OS thread object in property _thread_ and its thread id in property _thread_id_. This can be useful for controlling the thread directly. For example, to signal a kill. 5. _spawn-ctl_ has no affect on _join_, _wait_, or _watch_. This is because _spawn-ctl_ establishes an upper end throttle on the overall spawning process. When the number of spawns hits the max value, throttling (i.e. slowdown mode) takes affect and will expire if none of the promises resolve. Conversely, the arguments used by _join_, _wait_ and _watch_ control the sleep cycle and expiration of just those calls, not the spawned threads as a whole. When an expiration is set for, say, _join_, then that join will expire at that time. When an expiration is set in _spawn-ctl_, then if all the spawned threads as a whole don't resolve in time then an expiration function is called. **_Spawn Syntax:_** ``` my_promise = spawn `cmd` [args]: resolver block (promise, args) args passed in args return resolved or unresolved (True or False) ``` _Spawn with resolver arguments omitted_: ``` my_promise = spawn `cmd`: resolver block (promise, args) return resolved or unresolved (True or False) ``` _Simple spawn example_: ```buildoutcfg p = spawn `tar -zcvf /tmp/file.tar.gz /home/user/dir`: # Resolver block to which "promise" and "args" are passed # Resolver block is called when spawned command has completed for line in promise.output.stderr: print(line) # This marks the promise resolved return True # Wait for spawned command to resolve (not merely complete) try: p.join({"expire": 3}) print("tar resolved") except Exception as ex: print(ex.args) ``` _Example of file that overrides spawn controller parameters_: ``` #!/usr/bin/python3 def spawn_expired(promise, count): print("I do nothing just to demonstrate the error callback.") print(f"This command failed {promise.command} at this threshold {count}") raise Exception("Too many threads.") if __name__ == "__main__": # Example showing default values parms = {"max": 10, # Max number of threads allowed before slowdown mode "sleep-floor": .125, # Starting sleep value "sleep-ceiling": 3, # Maximum sleep value "sleep-increment": .125, # Incremental sleep value "expire": -1, # Default: no expiration "error": spawn_expired # Method called upon slowdown expiration } # Set spawn controller parameter values spawn-ctl parms ```
#### Join, Wait, or Watch Once commands are spawned, the caller can wait for _all_ promises, including inner or child promises, to complete, or the caller can wait for just a specific promise to complete. To wait for all _child_ promises including the promise on which you're calling this method, call _join()_. It will wait for that promise and all its children. To wait for just one specific promise, call _wait()_ on the promise of interest. To wait for _all_ promises in the promise tree, call _join()_ on the root promise. _join_ and _wait_ can be controlled through parameters. Each are iterators paused with a sleep method and will throw an expiration exception should you set a limit for iterations. If an expiration value is not set, no exception will be thrown and the cycle will run only until the promise(s) are resolved. _join_ and _wait_ are not affected by _spawn-ctl_. _watch_ is called to establish a separate asynchronous thread that will call back a function of your choosing should the command the promise is attached to time out. This is different than _join_ and _wait_ in that _watch_ is not synchronous and does not pause. This is used to keep an eye on a spawned command and take action should it hang. Your watcher function is passed the promise on which the watcher was attached, and the arguments, if any, from the spawn expression. If your command does not time out (i.e. hangs and expires), the watcher thread will quietly go away when the promise is resolved. _watch_ expiration is expressed in **seconds**, unlike _join_ and _wait_ which are expressed as total _iterations_ paused at the sleep value. _watch_'s polling cycle pause is .250 seconds, so the expiration value is multiplied by 4. The default expiration is 15 seconds. Examples: ``` # Spawn a thread running this command p = spawn `ls -lrt`: ## resolver block ## return True # Wait for promises, pause for 1/4 second each iteration, and throw an exception after 4 iterations (1 second) try: p.join({"sleep": .250, "expire": 4}) except Exception as ex: print(ex.args) # Wait for this promise, pause for 1 second each iteration, and throw an exception after 5 iterations (5 seconds) try: p.wait({"sleep": 1, "expire": 5}) except Exception as ex: print(ex.args) # My watcher function (called if spawned command never resolves by its experation period) def watcher(promise, args): print(f"This promise is likely hung: {promise.command}") print(f"and I still have the spawn expression's args: {args}") p = spawn `echo "hello" && sleep 5` args: print(f"Args passed to me: {args}") return True # Attach a watcher to this thread. It will be called upon experation. p.watch(watcher) print("watch() does not pause like join or wait") # Attach a watcher that will expire in 5 seconds p.watch(watcher, {"expire": 5}) ``` **_join_ syntax** ``` promise.join({optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of joining parent and children promises_: ``` p = spawn `ls *.txt`: for f in promise.output.stdout: cmd = f"tar -zcvf {f}.tar.gz {f}" spawn `$cmd` {"file":f}: print(f"{f} completed") promise.resolve_parent() return True return False # Wait for all commands to complete try: p.join({"sleep":1, "expire":20}) except Exception as ex: print(ex.args) ``` **_wait_ syntax** ``` promise.wait({optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of waiting on just the parent promise_: ``` p = spawn `ls *.txt`: for f in promise.output.stdout: cmd = f"tar -zcvf {f}.tar.gz {}" spawn `$cmd` {"file":f}: print(f"{f} completed") promise.resolve_parent() # Wait completes here return True return False # Wait for just the parent promise to complete try: p.wait({"sleep":1, "expire":20}) except Exception as ex: print(ex.args) ``` **_watch_ syntax** ``` promise.watch(callback, {optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of creating a watcher_: ```buildoutcfg # Define watcher method. Called if command times out (i.e. expires) def time_out(promise, args): print(f"Command {promise.command} timed out.") # Spawn a thread running some command that hangs p = spawn `long-running.sh`: print("Finally completed. Watcher method won't be called.") return True p.watch(time_out) # Does not wait. Calls method "time_out" if this promise expires (i.e. command hangs) # Do other things... ```
#### The Promise Tree Each _spawn_ issued inserts its promise object into the promise tree. The outermost _spawn_ will generate the root promise and each inner _spawn_ will be among its children. There's no limit to how far it can nest. _wait_ only applies to the promise on which it is called and is how it is different than _join_. _wait_ does not consider any other promise state but the one it's called for, whereas _join_ considers the one it's called for **and** anything below it in the tree. The promise tree can be printed with the ```dump_tree()``` method on the promise. This method is intended for diagnostic purposes where it must be determined why spawned commands hung. ```dump_tree(subtree)``` accepts a subtree promise as an argument. If no arguments are passed, ```dump_tree()``` dumps from the root promise on down. ``` # Simple example with no child promises p = spawn `date`: return True p.tree_dump() # Dump tree from root # or p.tree_dump(subtree_promise) # Dump tree from node in argument ``` Example dumping tree from subtree node: ```buildoutcfg # Complex example with child and grandchild promises # Demonstrates how to dump the promise tree from various points within it p = spawn `date`: # Spawn child command (child promise) spawn `pwd`: # Spawn a grandchild to the parent promise spawn `python --version`: promise.tree_dump(promise) # Dump the subtree from this point down return False # Spawn another child spawn `echo "blah"`: # Resolve parent promise promise.resolve_parent() # Resolve child promise return True # Do NOT resolve parent promise, let child do that return False p.join() p.tree_dump(p.children[0]) # Dump subtree from first child on down p.tree_dump(p.children[1]) # Dump subtree from the second child p.tree_dump(p.children[0].children[0]) # Dump subtree from the grandchild # Dump all children for c in p.children: p.tree_dump(c) ``` _Parent and child joins shown in these two examples_: ``` root_promise = spawn `ls -lr`: for file in promise.stdout: t = f"touch {file}" spawn `$t` {"file" file}: # This promise is a child of root print(f"{file} updated".) spawn `echo "done" > /tmp/done"`: # Another child promise (root's grandchild) print("Complete") promise.resolve_parent() return True promise.resolve_parent() return False return False root_promise.join() # Wait on the root promise and all its children. Thus, waiting for everything. ``` ``` root_promise = spawn `ls -lr`: for file in promise.output.stdout: t = f"touch {file}" spawn `$t` {"file" file}: # This promise is a child of root print(f"{promise.args['file'])} updated") promise.join() # Wait for this promise and its children but not its parent (root) spawn `echo "done" > /tmp/done"`: print("Complete") ``` _Resolving a parent promise_: ``` p = spawn `ls -lrt`: for f in promise.output.stdout: cmd = f"touch {f}" # Spawn command from this resolver and pass our promise spawn `$cmd`: print("Resolving all promises") promise.resolve_parent() # Resolve parent promise here return True # Resolve child promise return False # Do NOT resolve parent promise here p.join() # Wait for ALL promises to be resolved ```
### Results from Spawned Commands Spawned commands return their results in the _promise.output_ property of the _promise_ object passed to the resolver block, and in the spawn expression if there is an assignment in that spawn expression. The result properties can then be accessed as followed:
PropertyData TypeDescription
promise.output.stdoutListSTDOUT lines from the command normalized for display
promise.output.stderrListSTDERR lines from the command normalized for display
promise.output.exit_codeIntegerExit code value from command
promise.output.cwdStringCurrent working directory after command was executed
_Notes:_ 1. Watiba backticked commands can exist within the resolver 2. Other _spawn_ blocks can be embedded within a resolver (recursion allowed) 3. The command within the _spawn_ definition can be a variable (The same rules apply as for all backticked shell commands. This means the variable must contain pure shell commands.) 4. The leading dash to ignore CWD _cannot_ be used in the _spawn_ expression 5. The _promise.output_ object is not available until _promise.resolved()_ returns True _Simple example with the shell command as a Python variable_: ``` #!/usr/bin/python3 # run "date" command asynchronously d = 'date "+%Y/%m/%d"' spawn `$d`: print(promise.output.stdout[0]) return True ``` _Example with shell commands executed within resolver block_: ``` #!/usr/bin/python3 print("Running Watiba spawn with wait") `rm /tmp/done` # run "ls -lrt" command asynchronously p = spawn `ls -lrt`: print(f"Exit code: {promise.output.exit_code}") print(f"CWD: {promise.output.cwd}") print(f"STDERR: {promise.output.stderr}") # Loop through STDOUT from command for l in promise.output.stdout: print(l) `echo "Done" > /tmp/done` # Resolve promise return True # Pause until spawn command is complete p.wait() print("complete") ```
### Threads Each promise produced from a _spawn_ expression results in one OS thread. To access the number of threads your code has spawned collectively, you can do the following: ``` num_of_spawns = promise.spawn_count() # Returns number of nodes in the promise tree num_of_resolved_promises = promise.resolved_count() # Returns the number of promises resolved in tree ```
## Remote Execution Shell commands can be executed remotely. This is achieved though the SSH command, issued by Watiba, and has the following requirements: - OpenSSH is installed on the local and remote hosts - The local SSH key is in the remote's _authorized_keys_ file. _The details of this process is beyond the scope of this README. For those instructions, consult www.ssh.com_ - Make sure that SSH'ing to the target host does not cause any prompts. Test that your SSH environment is setup first by manually entering: ``` ssh {user}@{host} "ls -lrt" # For example ssh rwalk@walkubu "ls -lrt" # If SSH prompts you, then Watiba remote execution cannot function. ``` To execute a command remotely, a _@host_ parameter is suffixed to the backticked command. The host name can be a literal or a variable. To employ a variable, prepend a _$_ to the name following _@_ such as _@$var_.
#### Change SSH port for remote execution To change the default SSH port 22 to a custom value, add to your Watiba code: ```watiba-ctl {"ssh-port": custom port}``` Example: ```buildoutcfg watiba-ctl {"ssh-port": 2233} ``` Examples: ```buildoutcfg p = spawn `ls -lrt`@remoteserver {parms}: for line in promise.output.stdout: print(line) return True ``` ```buildoutcfg remotename = "serverB" p = spawn `ls -lrt`@$remotename {parms}: for line in p.output.stdout: print(line) return True ``` ```buildoutcfg out = `ls -lrt`@remoteserver for line in out.stdout: print(line) ``` ```buildoutcfg remotename = "serverB" out = `ls -lrt`@$remotename for line in out.stdout: print(line) ```
## Command Hooks Hooks are pre- or -post functions that are attached to a _command_ _pattern_, which is a regular expression (regex). Anytime Watiba encounters a command that matches the pattern for the hook, the hook function is called. All commands, spawned, remote, or local, can have Python functions executed **before** exection, by default, or **post hooks** that are run **after** the command. (Note: Post hooks are not run for spwaned commands because the resolver function is a post hook itself.) These functions can be passed arguments, too. ### Command Hook Expressions ``` # Run before commands that match that pattern hook-cmd "pattern" hook-function parms # Run before commands that match that pattern, but is non-recursive hook-cmd-nr "pattern" hook-function parms # Run after commands that match that pattern post-hook-cmd "pattern" hook-function parms # Run after commands that match that pattern, but is non-recursive post-hook-cmd-nr "pattern" hook-function parms ``` ### Hook Recursion Hooks, which are nothing more than Python functions called before or after a command is run, can issue their own commands and, thus, cause the hook to be recursively called. However, if the command in the hook block of code matches a command pattern that causes that same hook function to be run again, an infinte loop can occur. To prevent that, use the **-nr** suffix on the Watiba hook expression. (-nr stands for non-recursive.) This will ensure that the hook cannot be re-invoked for any commands that are within it.
To attach a hook: 1. Code one or more Python functions that will be the hooks. At the end of each hook, you must return True if the hook was successful, or False if something wrong. 2. Use the _hook-cmd_ expression to attach those hooks to a command pattern, which is a regular expression 3. To remove the hooks, use the _remove-hooks "pattern"_ expression. If a pattern, i.e. command regex pattern, is omitted, then all command hooks are removed. **hook-cmd "command pattern" function parms** The first parameter always passed to the hook function is the Python _match_ object from the command match. This is provided so the hook has access to the tokens on the command should it need them. Example: ``` def my_hook(match, parms): print(match.groups()) print(f'Tar file name is {match.group(1)}') print(parms["parmA"]) print(parms["parmB"]) return True # Successful execution def your_hook(match, parms): # This hook doesn't need the match object, so ignores it print(parms["something"]) if parms["something-else"] != "blah": return False # Failed execution return True # Successful excution # Add first hook to my tar command hook-cmd "tar -zcvf (\S.*)" my_hook: {"parmA":"A", "parmB":"B"} # Add another hook to my tar command hook-cmd "tar -zcvf (\S.*)" your_hook: {"parmD":1, "parmE":"something"} # Spawn command, but hooks will be invoked first... spawn `tar -zcvf files.tar.gz /tmp/files/* `: # Resolver code block return True # Resolve promise ``` Your parameters are whatever is valid for Python. These are simply passed to their attached functions, essentially each one's key is the function name, as specified. _Where are the hooks run for spawned commands?_ All hooks run under the thread of the issuer on the local host, not the target thread. _Where are the hooks run for remote commands?_ As with spawned commands, all hooks are issued on the local host, not the remote. Note that you can have remote backticked commands in your hook and that will run those remotely. If your remote command matches a hook(s) pattern, then those hooks will be run. This means if your command pattern for the first remote call runs a hook that contains another remote command that matches that same command pattern, then the hook is run again. Since this can lead to infinte hook loops, Watiba offers a non-recursive definition for the command pattern. Note that this non-recursive setting only applies to the command pattern and not the hook function itself. So if _hookA_ is run for two different command patterns, say, "ls -lrt" and "ls -laF" you can make one non-recusrive and still run the same hook for both commands. For the recursive command pattern, the hook has no limit to its recursion. For non-recursive, it will only be called once during the recursion process. To set a command pattern as non-recursive, use _hook-cmd-nr_. Example using a variation on a previous example: ``` def my_hook(match, parms) `tar -zcvf /tmp/files` # my_hook will NOT because for this command even though it matches print("Will be called only once!") return True # Note the "-nr" on the expression. That's for non-recursive hook-cmd-nr "tar -zcvf (\S.*)" my_hook: {"parmA":"A", "parmB":"B"} # my_hook will be called before this command runs ` tar -zcvf tarball.tar.gz /home/user/files.*` ```
## Command Chaining Watiba extends its remote command execution to chaining commands across multiple remote hosts. This is achieved by the _chain_ expression. This expression will execute the backticked command across a list of hosts, passed by the user, sequentially, synchronously until the hosts list is exhausted, or the command fails. _chain_ returns a Python dictionary where the keys are the host names and the values the WTOutput from the command run on that host. #### Chain Exception The _chain_ expression raises a WTChainException on the first failed command. The exception raised has the following properties: _WTChainException_:
PropertyData TypeDescription
commandStringCommand that failed
hostStringHost where command failed
messageStringError message
outputWTOutput structure: - stdout - stderr - exit_code - cwdOutput from command
Import this exception to catch it: ```buildoutcfg from watiba import WTChainException ``` Examples: ``` from watiba import WTChainException try: out = chain `tar -zcvf backup/file.tar.gz dir/*` {"hosts", ["serverA", "serverB"]} for host,output in out.items(): print(f'{host} exit code: {output.exit_code}') for line in output.stderr: print(line) except WTChainException(ex): print(f"Error: {ex.message}") print(f" host: {ex.host} exit code: {ex.output.exit_code} command: {ex.command}) ```
## Command Chain Piping (Experimental) The _chain_ expression supports piping STDOUT and/or STDERR to other commands executed on remote servers. Complex arrangements can be constructed through the Python dictionary passed to the _chain_ expression. The dictionary contents function as follows: - "hosts": [server, server, ...] This entry instructions _chain_ on which hosts the backticked command will run. This is a required entry. - "stdout": {server:command, server:command, ...} This is an optional entry. - "stderr": {server:command, server:command, ...} This is an optional entry. Just like a _chain_ expression that does not pipe output, the return object is a dictionary of WTOutput object keyed by the host name from the _hosts_ list and *not* from the commands recieving the piped output. If any command fails, a WTChainException is raised. Import this exception to catch it: ```buildoutcfg from watiba import WTChainException ``` _Note_: _The piping feature is experimental as of this release, and a better design will eventually supercede it._ Examples: ``` from watiba import WTChainException # This is a simple chain with no piping try: args = {"hosts": ["serverA", "serverB", "serverC"]} out = chain `ls -lrt dir/` args for host, output in out.items(): print(f'{host} exit code: {output.exit_code}') except WTChainException as ex: print(f'ERROR: {ex.message}, {ex.host}, {ex.command}, {ex.output.stderr}') ``` ``` # This is a more complex chain that runs the "ls -lrt" command on each server listed in "hosts" # and pipes the STDOUT output from serverC to serverV and serverD, to those commands, and serverB's STDERR # to serverX and its command try: args = {"hosts": ["serverA", "serverB", "serverC"], "stdout": {"serverC":{"serverV": "grep something", "serverD":"grep somethingelse"}}, "stderr": {"serverB":{"serverX": "cat >> /tmp/serverC.err"}} } out = chain `ls -lrt dir/` args for host, output in out.items(): print(f'{host} exit code: {output.exit_code}') except WTChainException as ex: print(f'ERROR: {ex.message}, {ex.host}, {ex.command}, {ex.output.stderr}') ``` ####How does this work? Watiba will run the backticked command in the expression on each host listed in _hosts_, in sequence and synchronously. If there is a "stdout" found in the arguments, then it will name the source host as the key, i.e. the host from which STDOUT will be read, and fed to each host and command listed under that host. This is true for STDERR as well. The method in which Watiba feeds the piped output is through a an _echo_ command shell piped to the command to be run on that host. So, "stdout": {"serverC":{"serverV": "grep something"}} causes Watiba to read each line of STDOUT from serverC and issue ```echo "$line" | grep something``` on serverV. It is piping from serverC to serverV.
## Installation ### PIP If you installed this as a Python package, e.g. pip, then the pre-compiler, _watiba-c_, will be placed in your system's PATH by PIP. ### GITHUB If you cloned this from github, you'll still need to install the package with pip, first, for the watbia module. Follow these steps to install Watiba locally. ``` # Watiba package required python3 -m pip install watiba ```
## Pre-compiling Test that the pre-compiler functions in your environment: ``` watiba-c version ``` For example: ```buildoutcfg rwalk@walkubu:~$ watiba-c version Watiba 0.3.26 ``` To pre-compile a .wt file: ``` watiba-c my_file.wt > my_file.py chmod +x my_file.py ./my_file.py ``` Where _my_file.wt_ is your Watiba code.
## Code Examples **my_file.wt** ``` #!/usr/bin/python3 # Stand alone commands. One with directory context, one without # This CWD will be active until a subsequent command changes it `cd /tmp` # Simple statement utilizing command and results in one statement print(`cd /tmp`.cwd) # This will not change the Watiba CWD context, because of the dash prefix, but within # the command itself the cd is honored. file.txt is created in /home/user/blah but # this does not impact the CWD of any subsequent commands. They # are still operating from the previous cd command to /tmp -`cd /home/user/blah && touch file.txt` # This will print "/tmp" _not_ /home because of the leading dash on the command print(f"CWD is not /home: {-`cd /home`.cwd)}" # This will find text files in /tmp/, not /home/user/blah (CWD context!) w=`find . -name '*.txt'` for l in w.stdout: print(f"File: {l}") # Embedding commands in print expressions that will print the stderr output, which tar writes to print(`echo "Some textual comment" > /tmp/blah.txt && tar -zcvf /tmp/blah.tar.gz /tmp`).stdout) # This will print the first line of stdout from the echo print(`echo "hello!"`.stdout[0]) # Example of more than one command in a statement line if len(`ls -lrt`.stdout) > 0 or len(-`cd /tmp`.stdout) > 0: print("You have stdout or stderr messages") # Example of a command as a Python varible and # receiving a Watiba object cmd = "tar -zcvf /tmp/watiba_test.tar.gz /mnt/data/git/watiba/src" cmd_results = `$cmd` if cmd_results.exit_code == 0: for l in cmd_results.stderr: print(l) # Simple reading of command output # Iterate on the stdout property for l in `cat blah.txt`.stdout: print(l) # Example of a failed command to see its exit code xc = `lsvv -lrt`.exit_code print(f"Return code: {xc}") # Example of running a command asynchronously and resolving promise spawn `cd /tmp && tar -zxvf tarball.tar.gz`: for l in promise.output.stderr: print(l) return True # Mark promise resolved # List dirs from CWD, iterate through them, spawn a tar command # then within the resolver, spawn a move command # Demonstrates spawns within resolvers for dir in `ls -d *`.stdout: tar = "tar -zcvf {}.tar.gz {}" prom = spawn `$tar` {"dir": dir}: print(f"{}args['dir'] tar complete") mv = f"mv -r {args['dir']}/* /tmp/." spawn `$mv`: print("Move done") # Resolve outer promise promise.resolve_parent() return True # Do not resolve this promise yet. Let the inner resolver do it return False prom.join() ``` %package help Summary: Development documents and examples for watiba Provides: python3-watiba-doc %description help # Watiba #### Version: **0.6.59** #### Date: 2021/12/04 Watiba, pronounced wah-TEE-bah, is a lightweight Python pre-compiler for embedding Linux shell commands within Python applications. It is similar to other languages' syntactical enhancements where XML or HTML is integrated into a language such as JavaScript. That is the concept applied here but integrating BASH shell commands with Python. As you browse this document, you'll find Watiba is rich with features for shell command integration with Python. Features: - Shell command integration with Python code - In-line access to shell command results - Current directory context maintained across commands throughout your Python code - Async/promise support for integrated shell commands - Remote shell command execution - Remote shell command chaining and piping ## Table of Contents 1. [Usage](#usage) 2. [Directory Context](#directory-context) 3. [Commands as Variables](#commands-as-variables) 4. [Command Results](#command-results) 5. [Asynchronous Spawning and Promises](#async-spawing-and-promises) 1. [Useful Properties in Promise](#useful-properties-in-promise) 2. [Spawn Controller](#spawn-controller) 3. [Join, Wait or Watch](#join-wait-watch) 4. [The Promise Tree](#promise-tree) 5. [Threads](#threads) 6. [Remote Execution](#remote-execution) 1. [Change SSH port for remote execution](#change-ssh-port) 7. [Command Hooks](#command-hooks) 8. [Command Chaining](#command-chaining) 9. [Command Chain Piping (Experimental)](#piping-output) 10. [Installation](#installation) 11. [Pre-compiling](#pre-compiling) 12. [Code Examples](#code-examples)
## Usage Watiba files, suffixed with ".wt", are Python programs containing embedded shell commands. Shell commands are expressed within backtick characters emulating BASH's original capture syntax. They can be placed in any Python statement or expression. Watiba keeps track of the current working directory after the execution of any shell command so that all subsequent shell commands keep context. For example: Basic example of embedded commands: ``` #!/usr/bin/python3 # Typical Python program if __name__ == "__main__": # Change directory context `cd /tmp` # Directory context maintained for file in `ls -lrt`.stdout: # In-line access to command results print(f"File in /tmp: {file}") ``` This loop will display the file list from /tmp. The `ls -lrt` is run in the context of previous `cd /tmp`.
#### Commands Expressed as Variables Commands within backticks can _be_ a variable, but cannot contain snippets of Python code or Python variables. The statement within the backticks _must_ be either a pure shell command or a Python variable containing a pure shell command. To execute commands in a Python variable, prefix the variable name between backticks with a dollar sign. _A command variable is denoted by prepending a dollar sign on the variable name within backticks_: ``` # Set the Python variable to the command cmdA = 'echo "This is a line of output" > /tmp/blah.txt' cmdB = 'cat /tmp/blah.txt' # Execute first command `$cmdA` # Execute the command within Python variable cmdA # Execute second command for line in `$cmdB`.stdout: print(line) ``` _This example demonstrates keeping dir context and executing a command by variable_: ``` #!/usr/bin/python3 if __name__ == "__main__": # Change CWD to /tmp `cd /tmp` # Set a command string my_cmd = "tar -zxvf tmp.tar.gz" # Execute that command and save the command results in variable "w" w = `$my_cmd` if w.exit_code == 0: for l in w.stderr: print(l) ``` _These constructs are **not** supported_: ``` file_name = "blah.txt" # Python variable within backticks `touch file_name` # NOT SUPPORTED! # Attempting to access Python variable with dollar sign `touch $file_name` # NOT SUPPORTED! # Python within backticks is NOT SUPPORTED! `if x not in l: ls -lrt x` ```
## Directory Context An important Watiba usage point is directory context is kept for dispersed shell commands. Any command that changes the shell's CWD is discovered and kept by Watiba. Watiba achieves this by tagging a `&& echo pwd` to the user's command, locating the result in the command's STDOUT, and finally setting the Python environment to that CWD with `os.chdir(dir)`. This is automatic and opaque to the user. The user will not see the results of the generated suffix. If the `echo` suffix presents a problem for the user, it can be eliminated by prefixing the leading backtick with a dash. The dash turns off the context tracking by not suffixing the command and so causes Watiba to lose its context. However, the context is maintained _within_ the set of commands in the backticks just not when it returns. For example, **out = -\`cd /tmp && ls -lrt\`** honors the ```cd``` within the scope of that execution line, but not for any backticked commands that follow later in your code. **_Warning!_** The dash will cause Watiba to lose its directory context should the command cause a CWD change either explicitly or implicitly. _Example_: ``` `cd /tmp` # Context will be kept # This will print from /home/user, but context is NOT kept for line in -`cd /home/user && ls -lrt`.stdout: print(line) # This will print from /tmp, not /home/user for line in `ls -lrt`.stdout: print(line) ```
## Command Results The results of the command issued in backticks are available in the properties of the object returned by Watiba. Following are those properties:
PropertyData TypeDescription
stdoutListSTDOUT lines from the command normalized for display
stderrListSTDERR lines from the command normalized for display
exit_codeIntegerExit code value from command
cwdStringCurrent working directory after command was executed
Technically, the returned object for any shell command is defined in the WTOutput class.
## Asynchronous Spawning and Promises Shell commands can be executed asynchronously with a defined resolver callback block. Each _spawn_ expression creates and runs a new OS thread. The resolver is a callback block that follows the Watiba _spawn_ expression. The spawn feature is executed when a ```spawn `cmd` args: resolver block``` code block is encountered. The resolver is passed the results in the promise object. (The promise structure contains the properties defined in section ["Results from Spawned Commands"](#spawn-results) The _spawn_ expression also returns a _promise_ object to the caller of _spawn_. The promise object is passed to the _resolver block_ in argument _promise_. The outer code can check its state with a call to _resolved()_ on the *returned* promise object. Output from the command is found in _promise.output_. The examples throughout this README and in the _examples.wt_ file make this clear.
##### Useful properties in promise structure A promise is either returned in assignment from outermost spawn, or passed to child spawns in argument "promise".
Property Data Type Description
hostStringHost name on which spawned command ran
childrenListChildren promises for this promise node
parentReferenceParent promise node of child promise. None if root promise.
commandStringShell command issued for this promise
resolved()MethodCall to find out if this promise is resolved
resolve_parent()MethodCall inside resolver block to resolve parent promise
tree_dump()MethodCall to show the promise tree. Takes subtree argument otherwise it defaults to the root promise
join()MethodCall to wait on on promise and all its children
wait()MethodCall to wait on just this promise
watch()MethodCall to create watcher on this promise
start_timeTimeTime that spawned command started
end_timeTimeTime that promise resolved
_Example of simple spawn_: ```buildoutcfg prom = spawn `tar -zcvf big_file.tar.gz some_dir/*`: # Resolver block to which "promise" and "args" is passed... print(f"{promise.command} completed.") return True # Resolve promise # Do other things while tar is running # Finally wait for tar promise to resolve prom.join() ```
#### Spawn Controller All spawned threads are managed by Watiba's Spawn Controller. The controller watches for too many threads and incrementally slows down each thread start when that threshold is exceeded until either all the promises in the tree resolve, or an expiration count is reached, at which time an exception is thrown on the last spawned command. This exception is raised by the default error method. This method as well as other spawn controlling parameters can be overridden. The controller's purpose is to not allow run away threads and provide signaling of possible hung threads. _spawn-ctl_ example: ```buildoutcfg # Only allow 20 spawns max, # and increase slowdown by 1/2 second each 3rd cycle ...python code... spawn-ctl {"max":20, "sleep-increment":.500} ``` Spawn control parameters:
Key Name Data Type Description Default
maxIntegerThe maximum number of spawned commands allowed before the controller enters slowdown mode10
sleep-floorIntegerSeconds of starting sleep value when the controller enters slowdown mode.125 (start at 1/8th second pause)
sleep-incrementIntegerSeconds the amount of seconds sleep will increase every 3rd cycle when in slowdown mode.125 (Increase pause 1/8th second every 3rd cycle)
sleep-ceilingIntegerSeconds the highest length sleep value allowed when in slowdown mode (As slow as it will get)3 (won't get slower than 3 second pauses)
expireIntegerTotal number of slowdown cycles allowed before the error method is calledNo expiration
errorMethod Callback method invoked when slowdown mode expires. Use this to catch hung commands. This method is passed 2 arguments: - **promise** - The promise attempting execution at the time of expiration - **count** - The thread count (unresolved promises) at the time of expiration Generic error handler. Just throws WTSpawnException that hold properties promise and message
**_spawn-ctl_** only overrides the values it sets and does not affect values not specified. _spawn-ctl_ statements can set whichever values it wants, can be dispersed throughout your code (i.e. multiple _spawn-ctl_ statements) and only affects subsequent spawn expressions. _Notes:_ 1. Arguments can be passed to the resolver by specifying a trailing variable after the command. If the arguments variable is omitted, an empty dictionary, i.e. {}, is passed to the resolver in _args_. **_Warning!_** Python threading does not deep copy objects passed as arguments to threads. What you place in ```args``` of the spawn expression will only be shallow copied so if there are references to other objects, it's not likely to survive the copy. 2. The resolver must return _True_ to set the promise to resolved, or _False_ to leave it unresolved. 3. A resolver can also set the promise to resolved by calling ```promise.set_resolved()```. This is handy in cases where a resolver has spawned another command and doesn't want the outer promise resolved until the inner resolvers are done. To resolve an outer, i.e. parent, resolver issue _promise.resolve_parent()_. Then the parent resolver can return _False_ at the end of its block so it leaves the resolved determination to the inner resolver block. 4. Each promise object holds its OS thread object in property _thread_ and its thread id in property _thread_id_. This can be useful for controlling the thread directly. For example, to signal a kill. 5. _spawn-ctl_ has no affect on _join_, _wait_, or _watch_. This is because _spawn-ctl_ establishes an upper end throttle on the overall spawning process. When the number of spawns hits the max value, throttling (i.e. slowdown mode) takes affect and will expire if none of the promises resolve. Conversely, the arguments used by _join_, _wait_ and _watch_ control the sleep cycle and expiration of just those calls, not the spawned threads as a whole. When an expiration is set for, say, _join_, then that join will expire at that time. When an expiration is set in _spawn-ctl_, then if all the spawned threads as a whole don't resolve in time then an expiration function is called. **_Spawn Syntax:_** ``` my_promise = spawn `cmd` [args]: resolver block (promise, args) args passed in args return resolved or unresolved (True or False) ``` _Spawn with resolver arguments omitted_: ``` my_promise = spawn `cmd`: resolver block (promise, args) return resolved or unresolved (True or False) ``` _Simple spawn example_: ```buildoutcfg p = spawn `tar -zcvf /tmp/file.tar.gz /home/user/dir`: # Resolver block to which "promise" and "args" are passed # Resolver block is called when spawned command has completed for line in promise.output.stderr: print(line) # This marks the promise resolved return True # Wait for spawned command to resolve (not merely complete) try: p.join({"expire": 3}) print("tar resolved") except Exception as ex: print(ex.args) ``` _Example of file that overrides spawn controller parameters_: ``` #!/usr/bin/python3 def spawn_expired(promise, count): print("I do nothing just to demonstrate the error callback.") print(f"This command failed {promise.command} at this threshold {count}") raise Exception("Too many threads.") if __name__ == "__main__": # Example showing default values parms = {"max": 10, # Max number of threads allowed before slowdown mode "sleep-floor": .125, # Starting sleep value "sleep-ceiling": 3, # Maximum sleep value "sleep-increment": .125, # Incremental sleep value "expire": -1, # Default: no expiration "error": spawn_expired # Method called upon slowdown expiration } # Set spawn controller parameter values spawn-ctl parms ```
#### Join, Wait, or Watch Once commands are spawned, the caller can wait for _all_ promises, including inner or child promises, to complete, or the caller can wait for just a specific promise to complete. To wait for all _child_ promises including the promise on which you're calling this method, call _join()_. It will wait for that promise and all its children. To wait for just one specific promise, call _wait()_ on the promise of interest. To wait for _all_ promises in the promise tree, call _join()_ on the root promise. _join_ and _wait_ can be controlled through parameters. Each are iterators paused with a sleep method and will throw an expiration exception should you set a limit for iterations. If an expiration value is not set, no exception will be thrown and the cycle will run only until the promise(s) are resolved. _join_ and _wait_ are not affected by _spawn-ctl_. _watch_ is called to establish a separate asynchronous thread that will call back a function of your choosing should the command the promise is attached to time out. This is different than _join_ and _wait_ in that _watch_ is not synchronous and does not pause. This is used to keep an eye on a spawned command and take action should it hang. Your watcher function is passed the promise on which the watcher was attached, and the arguments, if any, from the spawn expression. If your command does not time out (i.e. hangs and expires), the watcher thread will quietly go away when the promise is resolved. _watch_ expiration is expressed in **seconds**, unlike _join_ and _wait_ which are expressed as total _iterations_ paused at the sleep value. _watch_'s polling cycle pause is .250 seconds, so the expiration value is multiplied by 4. The default expiration is 15 seconds. Examples: ``` # Spawn a thread running this command p = spawn `ls -lrt`: ## resolver block ## return True # Wait for promises, pause for 1/4 second each iteration, and throw an exception after 4 iterations (1 second) try: p.join({"sleep": .250, "expire": 4}) except Exception as ex: print(ex.args) # Wait for this promise, pause for 1 second each iteration, and throw an exception after 5 iterations (5 seconds) try: p.wait({"sleep": 1, "expire": 5}) except Exception as ex: print(ex.args) # My watcher function (called if spawned command never resolves by its experation period) def watcher(promise, args): print(f"This promise is likely hung: {promise.command}") print(f"and I still have the spawn expression's args: {args}") p = spawn `echo "hello" && sleep 5` args: print(f"Args passed to me: {args}") return True # Attach a watcher to this thread. It will be called upon experation. p.watch(watcher) print("watch() does not pause like join or wait") # Attach a watcher that will expire in 5 seconds p.watch(watcher, {"expire": 5}) ``` **_join_ syntax** ``` promise.join({optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of joining parent and children promises_: ``` p = spawn `ls *.txt`: for f in promise.output.stdout: cmd = f"tar -zcvf {f}.tar.gz {f}" spawn `$cmd` {"file":f}: print(f"{f} completed") promise.resolve_parent() return True return False # Wait for all commands to complete try: p.join({"sleep":1, "expire":20}) except Exception as ex: print(ex.args) ``` **_wait_ syntax** ``` promise.wait({optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of waiting on just the parent promise_: ``` p = spawn `ls *.txt`: for f in promise.output.stdout: cmd = f"tar -zcvf {f}.tar.gz {}" spawn `$cmd` {"file":f}: print(f"{f} completed") promise.resolve_parent() # Wait completes here return True return False # Wait for just the parent promise to complete try: p.wait({"sleep":1, "expire":20}) except Exception as ex: print(ex.args) ``` **_watch_ syntax** ``` promise.watch(callback, {optional args}) Where args is a Python dictionary with the following options: "sleep" - seconds of sleep for each iteration (fractions such as .5 are honored) default: .5 seconds "expire" - number of sleep iterations until an excpetions is raised default: no expiration Note: "args" is optional and can be omitted ``` _Example of creating a watcher_: ```buildoutcfg # Define watcher method. Called if command times out (i.e. expires) def time_out(promise, args): print(f"Command {promise.command} timed out.") # Spawn a thread running some command that hangs p = spawn `long-running.sh`: print("Finally completed. Watcher method won't be called.") return True p.watch(time_out) # Does not wait. Calls method "time_out" if this promise expires (i.e. command hangs) # Do other things... ```
#### The Promise Tree Each _spawn_ issued inserts its promise object into the promise tree. The outermost _spawn_ will generate the root promise and each inner _spawn_ will be among its children. There's no limit to how far it can nest. _wait_ only applies to the promise on which it is called and is how it is different than _join_. _wait_ does not consider any other promise state but the one it's called for, whereas _join_ considers the one it's called for **and** anything below it in the tree. The promise tree can be printed with the ```dump_tree()``` method on the promise. This method is intended for diagnostic purposes where it must be determined why spawned commands hung. ```dump_tree(subtree)``` accepts a subtree promise as an argument. If no arguments are passed, ```dump_tree()``` dumps from the root promise on down. ``` # Simple example with no child promises p = spawn `date`: return True p.tree_dump() # Dump tree from root # or p.tree_dump(subtree_promise) # Dump tree from node in argument ``` Example dumping tree from subtree node: ```buildoutcfg # Complex example with child and grandchild promises # Demonstrates how to dump the promise tree from various points within it p = spawn `date`: # Spawn child command (child promise) spawn `pwd`: # Spawn a grandchild to the parent promise spawn `python --version`: promise.tree_dump(promise) # Dump the subtree from this point down return False # Spawn another child spawn `echo "blah"`: # Resolve parent promise promise.resolve_parent() # Resolve child promise return True # Do NOT resolve parent promise, let child do that return False p.join() p.tree_dump(p.children[0]) # Dump subtree from first child on down p.tree_dump(p.children[1]) # Dump subtree from the second child p.tree_dump(p.children[0].children[0]) # Dump subtree from the grandchild # Dump all children for c in p.children: p.tree_dump(c) ``` _Parent and child joins shown in these two examples_: ``` root_promise = spawn `ls -lr`: for file in promise.stdout: t = f"touch {file}" spawn `$t` {"file" file}: # This promise is a child of root print(f"{file} updated".) spawn `echo "done" > /tmp/done"`: # Another child promise (root's grandchild) print("Complete") promise.resolve_parent() return True promise.resolve_parent() return False return False root_promise.join() # Wait on the root promise and all its children. Thus, waiting for everything. ``` ``` root_promise = spawn `ls -lr`: for file in promise.output.stdout: t = f"touch {file}" spawn `$t` {"file" file}: # This promise is a child of root print(f"{promise.args['file'])} updated") promise.join() # Wait for this promise and its children but not its parent (root) spawn `echo "done" > /tmp/done"`: print("Complete") ``` _Resolving a parent promise_: ``` p = spawn `ls -lrt`: for f in promise.output.stdout: cmd = f"touch {f}" # Spawn command from this resolver and pass our promise spawn `$cmd`: print("Resolving all promises") promise.resolve_parent() # Resolve parent promise here return True # Resolve child promise return False # Do NOT resolve parent promise here p.join() # Wait for ALL promises to be resolved ```
### Results from Spawned Commands Spawned commands return their results in the _promise.output_ property of the _promise_ object passed to the resolver block, and in the spawn expression if there is an assignment in that spawn expression. The result properties can then be accessed as followed:
PropertyData TypeDescription
promise.output.stdoutListSTDOUT lines from the command normalized for display
promise.output.stderrListSTDERR lines from the command normalized for display
promise.output.exit_codeIntegerExit code value from command
promise.output.cwdStringCurrent working directory after command was executed
_Notes:_ 1. Watiba backticked commands can exist within the resolver 2. Other _spawn_ blocks can be embedded within a resolver (recursion allowed) 3. The command within the _spawn_ definition can be a variable (The same rules apply as for all backticked shell commands. This means the variable must contain pure shell commands.) 4. The leading dash to ignore CWD _cannot_ be used in the _spawn_ expression 5. The _promise.output_ object is not available until _promise.resolved()_ returns True _Simple example with the shell command as a Python variable_: ``` #!/usr/bin/python3 # run "date" command asynchronously d = 'date "+%Y/%m/%d"' spawn `$d`: print(promise.output.stdout[0]) return True ``` _Example with shell commands executed within resolver block_: ``` #!/usr/bin/python3 print("Running Watiba spawn with wait") `rm /tmp/done` # run "ls -lrt" command asynchronously p = spawn `ls -lrt`: print(f"Exit code: {promise.output.exit_code}") print(f"CWD: {promise.output.cwd}") print(f"STDERR: {promise.output.stderr}") # Loop through STDOUT from command for l in promise.output.stdout: print(l) `echo "Done" > /tmp/done` # Resolve promise return True # Pause until spawn command is complete p.wait() print("complete") ```
### Threads Each promise produced from a _spawn_ expression results in one OS thread. To access the number of threads your code has spawned collectively, you can do the following: ``` num_of_spawns = promise.spawn_count() # Returns number of nodes in the promise tree num_of_resolved_promises = promise.resolved_count() # Returns the number of promises resolved in tree ```
## Remote Execution Shell commands can be executed remotely. This is achieved though the SSH command, issued by Watiba, and has the following requirements: - OpenSSH is installed on the local and remote hosts - The local SSH key is in the remote's _authorized_keys_ file. _The details of this process is beyond the scope of this README. For those instructions, consult www.ssh.com_ - Make sure that SSH'ing to the target host does not cause any prompts. Test that your SSH environment is setup first by manually entering: ``` ssh {user}@{host} "ls -lrt" # For example ssh rwalk@walkubu "ls -lrt" # If SSH prompts you, then Watiba remote execution cannot function. ``` To execute a command remotely, a _@host_ parameter is suffixed to the backticked command. The host name can be a literal or a variable. To employ a variable, prepend a _$_ to the name following _@_ such as _@$var_.
#### Change SSH port for remote execution To change the default SSH port 22 to a custom value, add to your Watiba code: ```watiba-ctl {"ssh-port": custom port}``` Example: ```buildoutcfg watiba-ctl {"ssh-port": 2233} ``` Examples: ```buildoutcfg p = spawn `ls -lrt`@remoteserver {parms}: for line in promise.output.stdout: print(line) return True ``` ```buildoutcfg remotename = "serverB" p = spawn `ls -lrt`@$remotename {parms}: for line in p.output.stdout: print(line) return True ``` ```buildoutcfg out = `ls -lrt`@remoteserver for line in out.stdout: print(line) ``` ```buildoutcfg remotename = "serverB" out = `ls -lrt`@$remotename for line in out.stdout: print(line) ```
## Command Hooks Hooks are pre- or -post functions that are attached to a _command_ _pattern_, which is a regular expression (regex). Anytime Watiba encounters a command that matches the pattern for the hook, the hook function is called. All commands, spawned, remote, or local, can have Python functions executed **before** exection, by default, or **post hooks** that are run **after** the command. (Note: Post hooks are not run for spwaned commands because the resolver function is a post hook itself.) These functions can be passed arguments, too. ### Command Hook Expressions ``` # Run before commands that match that pattern hook-cmd "pattern" hook-function parms # Run before commands that match that pattern, but is non-recursive hook-cmd-nr "pattern" hook-function parms # Run after commands that match that pattern post-hook-cmd "pattern" hook-function parms # Run after commands that match that pattern, but is non-recursive post-hook-cmd-nr "pattern" hook-function parms ``` ### Hook Recursion Hooks, which are nothing more than Python functions called before or after a command is run, can issue their own commands and, thus, cause the hook to be recursively called. However, if the command in the hook block of code matches a command pattern that causes that same hook function to be run again, an infinte loop can occur. To prevent that, use the **-nr** suffix on the Watiba hook expression. (-nr stands for non-recursive.) This will ensure that the hook cannot be re-invoked for any commands that are within it.
To attach a hook: 1. Code one or more Python functions that will be the hooks. At the end of each hook, you must return True if the hook was successful, or False if something wrong. 2. Use the _hook-cmd_ expression to attach those hooks to a command pattern, which is a regular expression 3. To remove the hooks, use the _remove-hooks "pattern"_ expression. If a pattern, i.e. command regex pattern, is omitted, then all command hooks are removed. **hook-cmd "command pattern" function parms** The first parameter always passed to the hook function is the Python _match_ object from the command match. This is provided so the hook has access to the tokens on the command should it need them. Example: ``` def my_hook(match, parms): print(match.groups()) print(f'Tar file name is {match.group(1)}') print(parms["parmA"]) print(parms["parmB"]) return True # Successful execution def your_hook(match, parms): # This hook doesn't need the match object, so ignores it print(parms["something"]) if parms["something-else"] != "blah": return False # Failed execution return True # Successful excution # Add first hook to my tar command hook-cmd "tar -zcvf (\S.*)" my_hook: {"parmA":"A", "parmB":"B"} # Add another hook to my tar command hook-cmd "tar -zcvf (\S.*)" your_hook: {"parmD":1, "parmE":"something"} # Spawn command, but hooks will be invoked first... spawn `tar -zcvf files.tar.gz /tmp/files/* `: # Resolver code block return True # Resolve promise ``` Your parameters are whatever is valid for Python. These are simply passed to their attached functions, essentially each one's key is the function name, as specified. _Where are the hooks run for spawned commands?_ All hooks run under the thread of the issuer on the local host, not the target thread. _Where are the hooks run for remote commands?_ As with spawned commands, all hooks are issued on the local host, not the remote. Note that you can have remote backticked commands in your hook and that will run those remotely. If your remote command matches a hook(s) pattern, then those hooks will be run. This means if your command pattern for the first remote call runs a hook that contains another remote command that matches that same command pattern, then the hook is run again. Since this can lead to infinte hook loops, Watiba offers a non-recursive definition for the command pattern. Note that this non-recursive setting only applies to the command pattern and not the hook function itself. So if _hookA_ is run for two different command patterns, say, "ls -lrt" and "ls -laF" you can make one non-recusrive and still run the same hook for both commands. For the recursive command pattern, the hook has no limit to its recursion. For non-recursive, it will only be called once during the recursion process. To set a command pattern as non-recursive, use _hook-cmd-nr_. Example using a variation on a previous example: ``` def my_hook(match, parms) `tar -zcvf /tmp/files` # my_hook will NOT because for this command even though it matches print("Will be called only once!") return True # Note the "-nr" on the expression. That's for non-recursive hook-cmd-nr "tar -zcvf (\S.*)" my_hook: {"parmA":"A", "parmB":"B"} # my_hook will be called before this command runs ` tar -zcvf tarball.tar.gz /home/user/files.*` ```
## Command Chaining Watiba extends its remote command execution to chaining commands across multiple remote hosts. This is achieved by the _chain_ expression. This expression will execute the backticked command across a list of hosts, passed by the user, sequentially, synchronously until the hosts list is exhausted, or the command fails. _chain_ returns a Python dictionary where the keys are the host names and the values the WTOutput from the command run on that host. #### Chain Exception The _chain_ expression raises a WTChainException on the first failed command. The exception raised has the following properties: _WTChainException_:
PropertyData TypeDescription
commandStringCommand that failed
hostStringHost where command failed
messageStringError message
outputWTOutput structure: - stdout - stderr - exit_code - cwdOutput from command
Import this exception to catch it: ```buildoutcfg from watiba import WTChainException ``` Examples: ``` from watiba import WTChainException try: out = chain `tar -zcvf backup/file.tar.gz dir/*` {"hosts", ["serverA", "serverB"]} for host,output in out.items(): print(f'{host} exit code: {output.exit_code}') for line in output.stderr: print(line) except WTChainException(ex): print(f"Error: {ex.message}") print(f" host: {ex.host} exit code: {ex.output.exit_code} command: {ex.command}) ```
## Command Chain Piping (Experimental) The _chain_ expression supports piping STDOUT and/or STDERR to other commands executed on remote servers. Complex arrangements can be constructed through the Python dictionary passed to the _chain_ expression. The dictionary contents function as follows: - "hosts": [server, server, ...] This entry instructions _chain_ on which hosts the backticked command will run. This is a required entry. - "stdout": {server:command, server:command, ...} This is an optional entry. - "stderr": {server:command, server:command, ...} This is an optional entry. Just like a _chain_ expression that does not pipe output, the return object is a dictionary of WTOutput object keyed by the host name from the _hosts_ list and *not* from the commands recieving the piped output. If any command fails, a WTChainException is raised. Import this exception to catch it: ```buildoutcfg from watiba import WTChainException ``` _Note_: _The piping feature is experimental as of this release, and a better design will eventually supercede it._ Examples: ``` from watiba import WTChainException # This is a simple chain with no piping try: args = {"hosts": ["serverA", "serverB", "serverC"]} out = chain `ls -lrt dir/` args for host, output in out.items(): print(f'{host} exit code: {output.exit_code}') except WTChainException as ex: print(f'ERROR: {ex.message}, {ex.host}, {ex.command}, {ex.output.stderr}') ``` ``` # This is a more complex chain that runs the "ls -lrt" command on each server listed in "hosts" # and pipes the STDOUT output from serverC to serverV and serverD, to those commands, and serverB's STDERR # to serverX and its command try: args = {"hosts": ["serverA", "serverB", "serverC"], "stdout": {"serverC":{"serverV": "grep something", "serverD":"grep somethingelse"}}, "stderr": {"serverB":{"serverX": "cat >> /tmp/serverC.err"}} } out = chain `ls -lrt dir/` args for host, output in out.items(): print(f'{host} exit code: {output.exit_code}') except WTChainException as ex: print(f'ERROR: {ex.message}, {ex.host}, {ex.command}, {ex.output.stderr}') ``` ####How does this work? Watiba will run the backticked command in the expression on each host listed in _hosts_, in sequence and synchronously. If there is a "stdout" found in the arguments, then it will name the source host as the key, i.e. the host from which STDOUT will be read, and fed to each host and command listed under that host. This is true for STDERR as well. The method in which Watiba feeds the piped output is through a an _echo_ command shell piped to the command to be run on that host. So, "stdout": {"serverC":{"serverV": "grep something"}} causes Watiba to read each line of STDOUT from serverC and issue ```echo "$line" | grep something``` on serverV. It is piping from serverC to serverV.
## Installation ### PIP If you installed this as a Python package, e.g. pip, then the pre-compiler, _watiba-c_, will be placed in your system's PATH by PIP. ### GITHUB If you cloned this from github, you'll still need to install the package with pip, first, for the watbia module. Follow these steps to install Watiba locally. ``` # Watiba package required python3 -m pip install watiba ```
## Pre-compiling Test that the pre-compiler functions in your environment: ``` watiba-c version ``` For example: ```buildoutcfg rwalk@walkubu:~$ watiba-c version Watiba 0.3.26 ``` To pre-compile a .wt file: ``` watiba-c my_file.wt > my_file.py chmod +x my_file.py ./my_file.py ``` Where _my_file.wt_ is your Watiba code.
## Code Examples **my_file.wt** ``` #!/usr/bin/python3 # Stand alone commands. One with directory context, one without # This CWD will be active until a subsequent command changes it `cd /tmp` # Simple statement utilizing command and results in one statement print(`cd /tmp`.cwd) # This will not change the Watiba CWD context, because of the dash prefix, but within # the command itself the cd is honored. file.txt is created in /home/user/blah but # this does not impact the CWD of any subsequent commands. They # are still operating from the previous cd command to /tmp -`cd /home/user/blah && touch file.txt` # This will print "/tmp" _not_ /home because of the leading dash on the command print(f"CWD is not /home: {-`cd /home`.cwd)}" # This will find text files in /tmp/, not /home/user/blah (CWD context!) w=`find . -name '*.txt'` for l in w.stdout: print(f"File: {l}") # Embedding commands in print expressions that will print the stderr output, which tar writes to print(`echo "Some textual comment" > /tmp/blah.txt && tar -zcvf /tmp/blah.tar.gz /tmp`).stdout) # This will print the first line of stdout from the echo print(`echo "hello!"`.stdout[0]) # Example of more than one command in a statement line if len(`ls -lrt`.stdout) > 0 or len(-`cd /tmp`.stdout) > 0: print("You have stdout or stderr messages") # Example of a command as a Python varible and # receiving a Watiba object cmd = "tar -zcvf /tmp/watiba_test.tar.gz /mnt/data/git/watiba/src" cmd_results = `$cmd` if cmd_results.exit_code == 0: for l in cmd_results.stderr: print(l) # Simple reading of command output # Iterate on the stdout property for l in `cat blah.txt`.stdout: print(l) # Example of a failed command to see its exit code xc = `lsvv -lrt`.exit_code print(f"Return code: {xc}") # Example of running a command asynchronously and resolving promise spawn `cd /tmp && tar -zxvf tarball.tar.gz`: for l in promise.output.stderr: print(l) return True # Mark promise resolved # List dirs from CWD, iterate through them, spawn a tar command # then within the resolver, spawn a move command # Demonstrates spawns within resolvers for dir in `ls -d *`.stdout: tar = "tar -zcvf {}.tar.gz {}" prom = spawn `$tar` {"dir": dir}: print(f"{}args['dir'] tar complete") mv = f"mv -r {args['dir']}/* /tmp/." spawn `$mv`: print("Move done") # Resolve outer promise promise.resolve_parent() return True # Do not resolve this promise yet. Let the inner resolver do it return False prom.join() ``` %prep %autosetup -n watiba-0.6.59 %build %py3_build %install %py3_install install -d -m755 %{buildroot}/%{_pkgdocdir} if [ -d doc ]; then cp -arf doc %{buildroot}/%{_pkgdocdir}; fi if [ -d docs ]; then cp -arf docs %{buildroot}/%{_pkgdocdir}; fi if [ -d example ]; then cp -arf example %{buildroot}/%{_pkgdocdir}; fi if [ -d examples ]; then cp -arf examples %{buildroot}/%{_pkgdocdir}; fi pushd %{buildroot} if [ -d usr/lib ]; then find usr/lib -type f -printf "\"/%h/%f\"\n" >> filelist.lst fi if [ -d usr/lib64 ]; then find usr/lib64 -type f -printf "\"/%h/%f\"\n" >> filelist.lst fi if [ -d usr/bin ]; then find usr/bin -type f -printf "\"/%h/%f\"\n" >> filelist.lst fi if [ -d usr/sbin ]; then find usr/sbin -type f -printf "\"/%h/%f\"\n" >> filelist.lst fi touch doclist.lst if [ -d usr/share/man ]; then find usr/share/man -type f -printf "\"/%h/%f.gz\"\n" >> doclist.lst fi popd mv %{buildroot}/filelist.lst . mv %{buildroot}/doclist.lst . %files -n python3-watiba -f filelist.lst %dir %{python3_sitelib}/* %files help -f doclist.lst %{_docdir}/* %changelog * Thu Jun 08 2023 Python_Bot - 0.6.59-1 - Package Spec generated