+++ /dev/null
-#!/usr/bin/env python
-
-# arv-web enables you to run a custom web service from the contents of an Arvados collection.
-#
-# See http://doc.arvados.org/user/topics/arv-web.html
-
-import arvados
-import subprocess
-from arvados_fuse import Operations, SafeApi, CollectionDirectory
-import tempfile
-import os
-import llfuse
-import threading
-import Queue
-import argparse
-import logging
-import signal
-import sys
-import functools
-
-# Run an arvados_fuse mount under the control of the local process. This lets
-# us switch out the contents of the directory without having to unmount and
-# remount.
-def run_fuse_mount(api, collection):
- mountdir = tempfile.mkdtemp()
-
- operations = Operations(os.getuid(), os.getgid(), "utf-8")
- cdir = CollectionDirectory(llfuse.ROOT_INODE, operations.inodes, api, 2, collection)
- operations.inodes.add_entry(cdir)
-
- # Initialize the fuse connection
- llfuse.init(operations, mountdir, ['allow_other'])
-
- t = threading.Thread(None, llfuse.main)
- t.start()
-
- # wait until the driver is finished initializing
- operations.initlock.wait()
-
- return (mountdir, cdir)
-
-# Handle messages from Arvados event bus.
-def on_message(project, evqueue, ev):
- if 'event_type' in ev:
- old_attr = None
- if 'old_attributes' in ev['properties'] and ev['properties']['old_attributes']:
- old_attr = ev['properties']['old_attributes']
- if project not in (ev['properties']['new_attributes']['owner_uuid'],
- old_attr['owner_uuid'] if old_attr else None):
- return
-
- et = ev['event_type']
- if ev['event_type'] == 'update':
- if ev['properties']['new_attributes']['owner_uuid'] != ev['properties']['old_attributes']['owner_uuid']:
- if args.project_uuid == ev['properties']['new_attributes']['owner_uuid']:
- et = 'add'
- else:
- et = 'remove'
- if ev['properties']['new_attributes']['expires_at'] is not None:
- et = 'remove'
-
- evqueue.put((project, et, ev['object_uuid']))
-
-def main(argv):
- logger = logging.getLogger('arvados.arv-web')
- logger.setLevel(logging.INFO)
-
- parser = argparse.ArgumentParser()
- parser.add_argument('--project-uuid', type=str, required=True, help="Project uuid to watch")
- parser.add_argument('--port', type=int, default=8080, help="Host port to listen on (default 8080)")
- parser.add_argument('--image', type=str, help="Docker image to run")
-
- args = parser.parse_args(argv)
-
- api = SafeApi(arvados.config)
- project = args.project_uuid
- docker_image = args.image
- port = args.port
- evqueue = Queue.Queue()
-
- collections = api.collections().list(filters=[["owner_uuid", "=", project]],
- limit=1,
- order='modified_at desc').execute()['items']
- newcollection = collections[0]['uuid'] if len(collections) > 0 else None
- collection = None
-
- ws = arvados.events.subscribe(api, [["object_uuid", "is_a", "arvados#collection"]], functools.partial(on_message, project, evqueue))
-
- signal.signal(signal.SIGTERM, lambda signal, frame: sys.exit(0))
-
- loop = True
- cid = None
- docker_proc = None
- prev_docker_image = None
- mountdir = None
-
- try:
- while loop:
- loop = False
- if newcollection != collection:
- collection = newcollection
- if not mountdir:
- (mountdir, cdir) = run_fuse_mount(api, collection)
-
- with llfuse.lock:
- cdir.clear()
- if collection:
- # Switch the FUSE directory object so that it stores
- # the newly selected collection
- logger.info("Mounting %s", collection)
- cdir.collection_locator = collection
- cdir.collection_object = None
- cdir.update()
-
- try:
- try:
- if collection:
- if not args.image:
- docker_image = None
-
- # FUSE is asynchronous, so there is a race between
- # the directory being updated above and the kernel
- # cache being refreshed. This manifests as the
- # bizare behavior where os.path.exists() returns
- # True, but open() raises "file not found". The
- # workaround is to keep trying until the kernel
- # catches up.
- while not docker_image and os.path.exists(os.path.join(mountdir, "docker_image")):
- try:
- with open(os.path.join(mountdir, "docker_image")) as di:
- docker_image = di.read().strip()
- except IOError as e:
- pass
-
- if not docker_image:
- logger.error("Collection must contain a file 'docker_image' or must specify --image on the command line.")
-
- if docker_image and ((docker_image != prev_docker_image) or cid is None):
- if cid:
- logger.info("Stopping Docker container")
- subprocess.check_call(["docker", "stop", cid])
- cid = None
- docker_proc = None
-
- if docker_image:
- logger.info("Starting Docker container %s", docker_image)
- ciddir = tempfile.mkdtemp()
- cidfilepath = os.path.join(ciddir, "cidfile")
- docker_proc = subprocess.Popen(["docker", "run",
- "--cidfile=%s" % (cidfilepath),
- "--publish=%i:80" % (port),
- "--volume=%s:/mnt:ro" % mountdir,
- docker_image])
- cid = None
- while not cid and docker_proc.poll() is None:
- try:
- with open(cidfilepath) as cidfile:
- cid = cidfile.read().strip()
- except IOError:
- pass
- try:
- os.unlink(cidfilepath)
- os.rmdir(ciddir)
- except OSError:
- pass
-
- prev_docker_image = docker_image
- logger.info("Container id %s", cid)
- elif cid:
- logger.info("Sending refresh signal to container")
- # Send SIGHUP to all the processes inside the
- # container. By convention, services are expected
- # to reload their configuration. If they die
- # instead, that's okay, because then we'll just
- # start a new container.
- #
- # Getting the services inside the container to
- # refresh turned out to be really hard. Here are
- # some of the other things I tried:
- #
- # docker kill --signal=HUP # no effect
- # docker_proc.send_signal(signal.SIGHUP) # no effect
- # os.killpg(os.getpgid(docker_proc.pid), signal.SIGHUP) # docker-proxy dies as collatoral damage
- # docker exec apache2ctl restart # only works if service is using apache.
- # Sending HUP directly to the processes inside the container: permission denied
-
- subprocess.check_call(["docker", "exec", cid, "killall", "--regexp", ".*", "--signal", "HUP"])
- elif cid:
- logger.info("Stopping docker container")
- subprocess.check_call(["docker", "stop", cid])
- except subprocess.CalledProcessError:
- cid = None
-
- if not cid:
- logger.warning("No service running! Will wait for a new collection to appear in the project.")
- else:
- logger.info("Waiting for events")
-
- running = True
- loop = True
- while running:
- # Main run loop. Wait on project events, signals, or the
- # Docker container stopping.
-
- try:
- # Poll the queue with a 1 second timeout, if we have no
- # timeout the Python runtime doesn't have a chance to
- # process SIGINT or SIGTERM.
- eq = evqueue.get(True, 1)
- logger.info("%s %s", eq[1], eq[2])
- newcollection = collection
- if eq[1] in ('add', 'update', 'create'):
- newcollection = eq[2]
- elif eq[1] == 'remove':
- collections = api.collections().list(filters=[["owner_uuid", "=", project]],
- limit=1,
- order='modified_at desc').execute()['items']
- newcollection = collections[0]['uuid'] if len(collections) > 0 else None
- running = False
- except Queue.Empty:
- pass
-
- if docker_proc and docker_proc.poll() is not None:
- logger.warning("Service has terminated. Will try to restart.")
- cid = None
- docker_proc = None
- running = False
-
- except (KeyboardInterrupt):
- logger.info("Got keyboard interrupt")
- ws.close()
- loop = False
- except Exception as e:
- logger.exception(e)
- ws.close()
- loop = False
- finally:
- if cid:
- logger.info("Stopping docker container")
- subprocess.check_call(["docker", "stop", cid])
-
- if mountdir:
- logger.info("Unmounting")
- subprocess.call(["fusermount", "-u", "-z", mountdir])
- os.rmdir(mountdir)
-
-if __name__ == '__main__':
- main(sys.argv[1:])