watchStatus

#!/usr/bin/env python
#
# This file is part of antiSMASH.
#
# antiSMASH is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# antiSMASH is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with antiSMASH.  If not, see <http://www.gnu.org/licenses/>.
"""Watch the status directory for status updates from jobs
"""
import os
from os import path
import pyinotify
from argparse import ArgumentParser
from datetime import datetime
from dispatcher.storage import get_storage


version = "0.0.2"

class EventHandler(pyinotify.ProcessEvent):
    """Event handler to grab modify events"""
    def __init__(self, redis_store):
        self.redis_store = redis_store

    def get_job_id(self, event):
        return path.basename(event.pathname)

    def process_IN_CREATE(self, event):
        print "New job '%s'" % self.get_job_id(event)

    def process_IN_DELETE(self, event):
        print "Removing job '%s'" % self.get_job_id(event)

    def process_IN_MODIFY(self, event):
        jobid  = u'job:%s' % self.get_job_id(event)
        fh = None
        try:
            fh = open(event.pathname, 'r')
            status = fh.readline().strip()
            self.redis_store.hset(jobid, 'status', status)
            self.redis_store.hset(jobid, 'last_changed', datetime.utcnow())
        except IOError, e:
            print "Failed to get info for '%s': %s" % (jobid, e)
        finally:
            if fh is not None:
                fh.close()


def main():
    """Parse the command line, set up the database, start the main loop"""
    default_queue = os.getenv('AS_QUEUE', "redis://localhost:6379/0")
    parser = ArgumentParser(version=version)
    parser.add_argument('-q', '--queue', dest="queue",
                        help="URI of the database containing the job queue (default: %(default)s)",
                        default=default_queue)
    parser.add_argument('-s', '--statusdir', dest="statusdir",
                        default="/tmp/antismash_status",
                        help="Directory to keep job status files in (default: %(default)s)")
    options = parser.parse_args()

    redis_store = get_storage(options.queue)
    if not path.isdir(options.statusdir):
        os.mkdir(options.statusdir)

    wm = pyinotify.WatchManager()
    mask = pyinotify.IN_DELETE | pyinotify.IN_CREATE | pyinotify.IN_MODIFY

    handler = EventHandler(redis_store)
    notifier = pyinotify.Notifier(wm, handler)
    wdd = wm.add_watch(options.statusdir, mask, rec=True)
    notifier.loop()

if __name__ == "__main__":
    main()