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# this work for additional information regarding copyright ownership.
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# http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
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from __future__ import absolute_import
import logging
import os
import shutil
import signal
import socket
import subprocess
import tempfile
import threading
import time
import grpc
from future.moves.urllib.error import URLError
from future.moves.urllib.request import urlopen
from apache_beam.version import __version__ as beam_version
_LOGGER = logging.getLogger()
[docs]class SubprocessServer(object):
"""An abstract base class for running GRPC Servers as an external process.
This class acts as a context which will start up a server, provides a stub
to connect to it, and then shuts the server down. For example::
with SubprocessServer(GrpcStubClass, [executable, arg, ...]) as stub:
stub.CallService(...)
"""
def __init__(self, stub_class, cmd, port=None):
"""Creates the server object.
:param stub_class: the auto-generated GRPC client stub class used for
connecting to the GRPC service
:param cmd: command (including arguments) for starting up the server,
suitable for passing to `subprocess.POpen`.
:param port: (optional) the port at which the subprocess will serve its
service. If not given, one will be randomly chosen and the special
string "{{PORT}}" will be substituted in the command line arguments
with the chosen port.
"""
self._process_lock = threading.RLock()
self._process = None
self._stub_class = stub_class
self._cmd = [str(arg) for arg in cmd]
self._port = port
def __enter__(self):
return self.start()
def __exit__(self, *unused_args):
self.stop()
[docs] def start(self):
with self._process_lock:
if self._process:
self.stop()
if self._port:
port = self._port
cmd = self._cmd
else:
port, = pick_port(None)
cmd = [arg.replace('{{PORT}}', str(port)) for arg in self._cmd]
endpoint = 'localhost:%s' % port
_LOGGER.warning("Starting service with %s", str(cmd).replace("',", "'"))
try:
self._process = subprocess.Popen(cmd)
wait_secs = .1
channel = grpc.insecure_channel(endpoint)
channel_ready = grpc.channel_ready_future(channel)
while True:
if self._process.poll() is not None:
_LOGGER.error("Starting job service with %s", cmd)
raise RuntimeError(
'Service failed to start up with error %s' %
self._process.poll())
try:
channel_ready.result(timeout=wait_secs)
break
except (grpc.FutureTimeoutError, grpc._channel._Rendezvous):
wait_secs *= 1.2
logging.log(logging.WARNING if wait_secs > 1 else logging.DEBUG,
'Waiting for grpc channel to be ready at %s.',
endpoint)
return self._stub_class(channel)
except: # pylint: disable=bare-except
_LOGGER.exception("Error bringing up service")
self.stop()
raise
[docs] def stop(self):
with self._process_lock:
if not self._process:
return
for _ in range(5):
if self._process.poll() is not None:
break
logging.debug("Sending SIGINT to job_server")
self._process.send_signal(signal.SIGINT)
time.sleep(1)
if self._process.poll() is None:
self._process.kill()
self._process = None
[docs] def local_temp_dir(self, **kwargs):
return tempfile.mkdtemp(dir=self._local_temp_root, **kwargs)
[docs]class JavaJarServer(SubprocessServer):
APACHE_REPOSITORY = 'https://repo.maven.apache.org/maven2'
BEAM_GROUP_ID = 'org.apache.beam'
JAR_CACHE = os.path.expanduser("~/.apache_beam/cache/jars")
def __init__(self, stub_class, path_to_jar, java_arguments):
super(JavaJarServer, self).__init__(
stub_class, ['java', '-jar', path_to_jar] + list(java_arguments))
[docs] @classmethod
def jar_name(cls, artifact_id, version, classifier=None, appendix=None):
return '-'.join(filter(
None, [artifact_id, appendix, version, classifier])) + '.jar'
[docs] @classmethod
def path_to_maven_jar(
cls,
artifact_id,
group_id,
version,
repository=APACHE_REPOSITORY,
classifier=None):
return '/'.join([
repository,
group_id.replace('.', '/'),
artifact_id,
version,
cls.jar_name(artifact_id, version, classifier)])
[docs] @classmethod
def path_to_beam_jar(cls, gradle_target, appendix=None):
gradle_package = gradle_target.strip(':')[:gradle_target.rindex(':')]
artifact_id = 'beam-' + gradle_package.replace(':', '-')
project_root = os.path.sep.join(
os.path.abspath(__file__).split(os.path.sep)[:-5])
local_path = os.path.join(
project_root,
gradle_package.replace(':', os.path.sep),
'build',
'libs',
cls.jar_name(
artifact_id,
beam_version.replace('.dev', ''),
classifier='SNAPSHOT',
appendix=appendix))
if os.path.exists(local_path):
_LOGGER.info('Using pre-built snapshot at %s', local_path)
return local_path
elif '.dev' in beam_version:
# TODO: Attempt to use nightly snapshots?
raise RuntimeError(
('%s not found. '
'Please build the server with \n cd %s; ./gradlew %s') % (
local_path, os.path.abspath(project_root), gradle_target))
else:
return cls.path_to_maven_jar(
artifact_id, cls.BEAM_GROUP_ID, beam_version, cls.APACHE_REPOSITORY)
[docs] @classmethod
def local_jar(cls, url):
# TODO: Verify checksum?
if os.path.exists(url):
return url
else:
_LOGGER.warning('Downloading job server jar from %s' % url)
cached_jar = os.path.join(cls.JAR_CACHE, os.path.basename(url))
if not os.path.exists(cached_jar):
if not os.path.exists(cls.JAR_CACHE):
os.makedirs(cls.JAR_CACHE)
# TODO: Clean up this cache according to some policy.
try:
url_read = urlopen(url)
with open(cached_jar + '.tmp', 'wb') as jar_write:
shutil.copyfileobj(url_read, jar_write, length=1 << 20)
os.rename(cached_jar + '.tmp', cached_jar)
except URLError as e:
raise RuntimeError(
'Unable to fetch remote job server jar at %s: %s' % (url, e))
return cached_jar
[docs]def pick_port(*ports):
"""
Returns a list of ports, same length as input ports list, but replaces
all None or 0 ports with a random free port.
"""
sockets = []
def find_free_port(port):
if port:
return port
else:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sockets.append(s)
s.bind(('localhost', 0))
_, free_port = s.getsockname()
return free_port
ports = list(map(find_free_port, ports))
# Close sockets only now to avoid the same port to be chosen twice
for s in sockets:
s.close()
return ports