#!/usr/bin/env python

import optparse
import os
import signal
import subprocess
import sys


if __name__ == '__main__':
    parser = optparse.OptionParser(usage='''%prog [options]

Lists and optionally kills orphaned Swift processes. This is done by scanning
/var/run/swift for .pid files and listing any processes that look like Swift
processes but aren't associated with the pids in those .pid files. Any Swift
processes running with the 'once' parameter are ignored, as those are usually
for full-speed audit scans and such.

Example (sends SIGTERM to all orphaned Swift processes older than two hours):
%prog -a 2 -k TERM
        '''.strip())
    parser.add_option('-a', '--age', dest='hours', type='int', default=24,
        help='look for processes at least HOURS old; default: 24')
    parser.add_option('-k', '--kill', dest='signal',
        help='send SIGNAL to matched processes; default: just list process '
             'information')
    parser.add_option('-w', '--wide', dest='wide', default=False,
        action='store_true', help="don't clip the listing at 80 characters")
    (options, args) = parser.parse_args()

    pids = []
    for root, directories, files in os.walk('/var/run/swift'):
        for name in files:
            if name.endswith('.pid'):
                pids.append(open(os.path.join(root, name)).read().strip())
                pids.extend(subprocess.Popen(
                    ['ps', '--ppid', pids[-1], '-o', 'pid', '--no-headers'],
                    stdout=subprocess.PIPE).communicate()[0].split())

    listing = []
    for line in subprocess.Popen(
            ['ps', '-eo', 'etime,pid,args', '--no-headers'],
            stdout=subprocess.PIPE).communicate()[0].split('\n'):
        if not line:
            continue
        hours = 0
        try:
            etime, pid, args = line.split(None, 2)
        except ValueError:
            sys.exit('Could not process ps line %r' % line)
        if pid in pids:
            continue
        if (not args.startswith('/usr/bin/python /usr/bin/swift-') and
            not args.startswith('/usr/bin/python /usr/local/bin/swift-')) or \
                'swift-orphans' in args or \
                'once' in args.split():
            continue
        args = args.split('-', 1)[1]
        etime = etime.split('-')
        if len(etime) == 2:
            hours = int(etime[0]) * 24
            etime = etime[1]
        elif len(etime) == 1:
            etime = etime[0]
        else:
            sys.exit('Could not process etime value from %r' % line)
        etime = etime.split(':')
        if len(etime) == 3:
            hours += int(etime[0])
        elif len(etime) != 2:
            sys.exit('Could not process etime value from %r' % line)
        if hours >= options.hours:
            listing.append((str(hours), pid, args))

    if not listing:
        exit()

    hours_len = len('Hours')
    pid_len = len('PID')
    args_len = len('Command')
    for hours, pid, args in listing:
        hours_len = max(hours_len, len(hours))
        pid_len = max(pid_len, len(pid))
        args_len = max(args_len, len(args))
    args_len = min(args_len, 78 - hours_len - pid_len)

    print ('%%%ds %%%ds %%s' % (hours_len, pid_len)) % \
          ('Hours', 'PID', 'Command')
    for hours, pid, args in listing:
        print ('%%%ds %%%ds %%s' % (hours_len, pid_len)) % \
              (hours, pid, args[:args_len])

    if options.signal:
        try:
            signum = int(options.signal)
        except ValueError:
            signum = getattr(signal, options.signal.upper(),
                         getattr(signal, 'SIG' + options.signal.upper(), None))
        if not signum:
            sys.exit('Could not translate %r to a signal number.' %
                     options.signal)
        print 'Sending processes %s (%d) signal...' % (options.signal, signum),
        for hours, pid, args in listing:
            os.kill(int(pid), signum)
        print 'Done.'