#!/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
+from arvados.safeapi import ThreadSafeApiCache
import subprocess
-from arvados_fuse import Operations, SafeApi, CollectionDirectory
+from arvados_fuse import Operations, CollectionDirectory
import tempfile
import os
import llfuse
import logging
import signal
import sys
+import functools
+
+logger = logging.getLogger('arvados.arv-web')
+logger.setLevel(logging.INFO)
+
+class ArvWeb(object):
+ def __init__(self, project, docker_image, port):
+ self.project = project
+ self.loop = True
+ self.cid = None
+ self.prev_docker_image = None
+ self.mountdir = None
+ self.collection = None
+ self.override_docker_image = docker_image
+ self.port = port
+ self.evqueue = Queue.Queue()
+ self.api = ThreadSafeApiCache(arvados.config.settings())
+
+ if arvados.util.group_uuid_pattern.match(project) is None:
+ raise arvados.errors.ArgumentError("Project uuid is not valid")
+
+ collections = self.api.collections().list(filters=[["owner_uuid", "=", project]],
+ limit=1,
+ order='modified_at desc').execute()['items']
+ self.newcollection = collections[0]['uuid'] if collections else None
+
+ self.ws = arvados.events.subscribe(self.api, [["object_uuid", "is_a", "arvados#collection"]], self.on_message)
+
+ def check_docker_running(self):
+ # It would be less hacky to use "docker events" than poll "docker ps"
+ # but that would require writing a bigger pile of code.
+ if self.cid:
+ ps = subprocess.check_output(["docker", "ps", "--no-trunc=true", "--filter=status=running"])
+ for l in ps.splitlines():
+ if l.startswith(self.cid):
+ return True
+ return False
+
+ # Handle messages from Arvados event bus.
+ def on_message(self, 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 self.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 self.project == ev['properties']['new_attributes']['owner_uuid']:
+ et = 'add'
+ else:
+ et = 'remove'
+ if ev['properties']['new_attributes']['expires_at'] is not None:
+ et = 'remove'
+
+ self.evqueue.put((self.project, et, ev['object_uuid']))
+
+ # 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(self):
+ self.mountdir = tempfile.mkdtemp()
+
+ self.operations = Operations(os.getuid(), os.getgid(), self.api, "utf-8")
+ self.cdir = CollectionDirectory(llfuse.ROOT_INODE, self.operations.inodes, self.api, 2, self.collection)
+ self.operations.inodes.add_entry(self.cdir)
+
+ # Initialize the fuse connection
+ llfuse.init(self.operations, self.mountdir, ['allow_other'])
+
+ t = threading.Thread(None, llfuse.main)
+ t.start()
+
+ # wait until the driver is finished initializing
+ self.operations.initlock.wait()
+
+ def mount_collection(self):
+ if self.newcollection != self.collection:
+ self.collection = self.newcollection
+ if not self.mountdir and self.collection:
+ self.run_fuse_mount()
+
+ if self.mountdir:
+ with llfuse.lock:
+ self.cdir.clear()
+ # Switch the FUSE directory object so that it stores
+ # the newly selected collection
+ if self.collection:
+ logger.info("Mounting %s", self.collection)
+ else:
+ logger.info("Mount is empty")
+ self.cdir.change_collection(self.collection)
+
+
+ def stop_docker(self):
+ if self.cid:
+ logger.info("Stopping Docker container")
+ subprocess.call(["docker", "stop", self.cid])
+ self.cid = None
+
+ def run_docker(self):
+ try:
+ if self.collection is None:
+ self.stop_docker()
+ return
+
+ docker_image = None
+ if self.override_docker_image:
+ docker_image = self.override_docker_image
+ else:
+ try:
+ with llfuse.lock:
+ if "docker_image" in self.cdir:
+ docker_image = self.cdir["docker_image"].readfrom(0, 1024).strip()
+ except IOError as e:
+ pass
+
+ has_reload = False
+ try:
+ with llfuse.lock:
+ has_reload = "reload" in self.cdir
+ except IOError as e:
+ pass
-logging.basicConfig(level=logging.INFO)
-
-parser = argparse.ArgumentParser()
-parser.add_argument('--project', type=str, required=True, help="Project to watch")
-parser.add_argument('--port', type=int, default=8080, help="Local bind port")
-parser.add_argument('--image', type=str, help="Docker image to run")
-
-args = parser.parse_args()
-
-api = SafeApi(arvados.config)
-project = args.project
-docker_image = args.image
-port = args.port
-evqueue = Queue.Queue()
-
-def run_fuse_mount(collection):
- global api
-
- mountdir = tempfile.mkdtemp()
-
- operations = Operations(os.getuid(), os.getgid(), "utf-8", True)
- operations.inodes.add_entry(CollectionDirectory(llfuse.ROOT_INODE, operations.inodes, api, 2, collection))
-
- # Initialize the fuse connection
- llfuse.init(operations, mountdir, ['allow_other'])
-
- t = threading.Thread(None, lambda: llfuse.main())
- t.start()
-
- # wait until the driver is finished initializing
- operations.initlock.wait()
-
- return mountdir
-
-def on_message(ev):
- global project
- global evqueue
-
- 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
+ if docker_image is None:
+ logger.error("Collection must contain a file 'docker_image' or must specify --image on the command line.")
+ self.stop_docker()
+ return
- et = ev['event_type']
- if ev['event_type'] == 'update' and ev['properties']['new_attributes']['owner_uuid'] != ev['properties']['old_attributes']['owner_uuid']:
- if args.project == ev['properties']['new_attributes']['owner_uuid']:
- et = 'add'
- else:
- et = 'remove'
+ if docker_image == self.prev_docker_image and self.cid is not None and has_reload:
+ logger.info("Running container reload command")
+ subprocess.check_call(["docker", "exec", self.cid, "/mnt/reload"])
+ return
- evqueue.put((project, et, ev['object_uuid']))
+ self.stop_docker()
-collection = api.collections().list(filters=[["owner_uuid", "=", project]],
- limit=1,
- order='modified_at desc').execute()['items'][0]['uuid']
+ logger.info("Starting Docker container %s", docker_image)
+ self.cid = subprocess.check_output(["docker", "run",
+ "--detach=true",
+ "--publish=%i:80" % (self.port),
+ "--volume=%s:/mnt:ro" % self.mountdir,
+ docker_image]).strip()
-ws = arvados.events.subscribe(api, [["object_uuid", "is_a", "arvados#collection"]], on_message)
+ self.prev_docker_image = docker_image
+ logger.info("Container id %s", self.cid)
-signal.signal(signal.SIGTERM, lambda signal, frame: sys.exit(0))
+ except subprocess.CalledProcessError:
+ self.cid = None
-loop = True
-cid = None
-while loop:
- loop = False
- logging.info("Mounting %s" % collection)
- mountdir = run_fuse_mount(collection)
+ def wait_for_events(self):
+ if not self.cid:
+ logger.warning("No service running! Will wait for a new collection to appear in the project.")
+ else:
+ logger.info("Waiting for events")
- try:
- if not args.image:
- if os.path.exists(os.path.join(mountdir, "docker_image")):
- with open(os.path.join(mountdir, "docker_image")) as di:
- docker_image = di.read().strip()
- else:
- logging.error("Collection must contain a file 'docker_image' or must specify --image on the command line.")
- sys.exit(1)
-
- logging.info("Starting docker container")
- cid = subprocess.check_output(["docker", "run",
- "--detach=true",
- "--publish=%i:80" % (port),
- "--volume=%s:/mnt:ro" % mountdir,
- docker_image])
- cid = cid.rstrip()
- logging.info("Container id is %s" % cid)
-
- logging.info("Waiting for events")
running = True
- loop = True
+ self.loop = True
while running:
+ # Main run loop. Wait on project events, signals, or the
+ # Docker container stopping.
+
try:
- eq = evqueue.get(True, 1)
- logging.info("%s %s" % (eq[1], eq[2]))
- newcollection = collection
+ # 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 = self.evqueue.get(True, 1)
+ logger.info("%s %s", eq[1], eq[2])
+ self.newcollection = self.collection
if eq[1] in ('add', 'update', 'create'):
- newcollection = eq[2]
+ self.newcollection = eq[2]
elif eq[1] == 'remove':
- newcollection = api.collections().list(filters=[["owner_uuid", "=", project]],
+ collections = self.api.collections().list(filters=[["owner_uuid", "=", self.project]],
limit=1,
- order='modified_at desc').execute()['items'][0]['uuid']
- if newcollection != collection:
- logging.info("restarting web service")
- collection = newcollection
- running = False
+ order='modified_at desc').execute()['items']
+ self.newcollection = collections[0]['uuid'] if collections else None
+ running = False
except Queue.Empty:
pass
- except (KeyboardInterrupt):
- logging.info("Got keyboard interrupt")
- ws.close()
- loop = False
- except Exception as e:
- logging.exception(str(e))
- ws.close()
- loop = False
- finally:
- if cid:
- logging.info("Stopping docker container")
- cid = subprocess.call(["docker", "stop", cid])
-
- logging.info("Unmounting")
- subprocess.call(["fusermount", "-u", "-z", mountdir])
- os.rmdir(mountdir)
+
+ if self.cid and not self.check_docker_running():
+ logger.warning("Service has terminated. Will try to restart.")
+ self.cid = None
+ running = False
+
+
+ def run(self):
+ try:
+ while self.loop:
+ self.loop = False
+ self.mount_collection()
+ try:
+ self.run_docker()
+ self.wait_for_events()
+ except (KeyboardInterrupt):
+ logger.info("Got keyboard interrupt")
+ self.ws.close()
+ self.loop = False
+ except Exception as e:
+ logger.exception("Caught fatal exception, shutting down")
+ self.ws.close()
+ self.loop = False
+ finally:
+ self.stop_docker()
+
+ if self.mountdir:
+ logger.info("Unmounting")
+ subprocess.call(["fusermount", "-u", self.mountdir])
+ os.rmdir(self.mountdir)
+
+
+def main(argv):
+ 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)
+
+ signal.signal(signal.SIGTERM, lambda signal, frame: sys.exit(0))
+
+ try:
+ arvweb = ArvWeb(args.project_uuid, args.image, args.port)
+ arvweb.run()
+ except arvados.errors.ArgumentError as e:
+ logger.error(e)
+ return 1
+
+ return 0
+
+if __name__ == '__main__':
+ sys.exit(main(sys.argv[1:]))