1eab25f292
* Fix paver violations to stablize edx-lint update * Parens, Line2Long * Fix missing docstrings * Fix PEP8 issues * Address PR feedback (thanks @nedbat!)
125 lines
3.3 KiB
Python
125 lines
3.3 KiB
Python
"""
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Helper functions for managing processes.
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"""
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from __future__ import print_function
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import sys
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import os
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import subprocess
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import signal
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import psutil
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import atexit
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from paver import tasks
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def kill_process(proc):
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"""
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Kill the process `proc` created with `subprocess`.
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"""
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p1_group = psutil.Process(proc.pid)
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# pylint: disable=unexpected-keyword-arg
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child_pids = p1_group.get_children(recursive=True)
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for child_pid in child_pids:
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os.kill(child_pid.pid, signal.SIGKILL)
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def run_multi_processes(cmd_list, out_log=None, err_log=None):
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"""
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Run each shell command in `cmd_list` in a separate process,
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piping stdout to `out_log` (a path) and stderr to `err_log` (also a path).
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Terminates the processes on CTRL-C and ensures the processes are killed
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if an error occurs.
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"""
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kwargs = {'shell': True, 'cwd': None}
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pids = []
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if out_log:
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out_log_file = open(out_log, 'w')
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kwargs['stdout'] = out_log_file
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if err_log:
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err_log_file = open(err_log, 'w')
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kwargs['stderr'] = err_log_file
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# If the user is performing a dry run of a task, then just log
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# the command strings and return so that no destructive operations
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# are performed.
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if tasks.environment.dry_run:
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for cmd in cmd_list:
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tasks.environment.info(cmd)
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return
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try:
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for cmd in cmd_list:
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pids.extend([subprocess.Popen(cmd, **kwargs)])
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# pylint: disable=unused-argument
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def _signal_handler(*args):
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"""
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What to do when process is ended
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"""
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print("\nEnding...")
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signal.signal(signal.SIGINT, _signal_handler)
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print("Enter CTL-C to end")
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signal.pause()
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print("Processes ending")
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# pylint: disable=broad-except
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except Exception as err:
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print("Error running process {}".format(err), file=sys.stderr)
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finally:
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for pid in pids:
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kill_process(pid)
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def run_process(cmd, out_log=None, err_log=None):
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"""
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Run the shell command `cmd` in a separate process,
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piping stdout to `out_log` (a path) and stderr to `err_log` (also a path).
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Terminates the process on CTRL-C or if an error occurs.
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"""
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return run_multi_processes([cmd], out_log=out_log, err_log=err_log)
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def run_background_process(cmd, out_log=None, err_log=None, cwd=None):
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"""
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Runs a command as a background process. Sends SIGINT at exit.
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"""
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kwargs = {'shell': True, 'cwd': cwd}
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if out_log:
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out_log_file = open(out_log, 'w')
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kwargs['stdout'] = out_log_file
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if err_log:
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err_log_file = open(err_log, 'w')
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kwargs['stderr'] = err_log_file
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proc = subprocess.Popen(cmd, **kwargs)
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def exit_handler():
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"""
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Send SIGINT to the process's children. This is important
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for running commands under coverage, as coverage will not
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produce the correct artifacts if the child process isn't
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killed properly.
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"""
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p1_group = psutil.Process(proc.pid)
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# pylint: disable=unexpected-keyword-arg
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child_pids = p1_group.get_children(recursive=True)
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for child_pid in child_pids:
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os.kill(child_pid.pid, signal.SIGINT)
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# Wait for process to actually finish
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proc.wait()
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atexit.register(exit_handler)
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