Source code for apache_beam.utils.subprocess_server

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# pytype: skip-file

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(__name__)

[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"Starting service with %s", str(cmd).replace("',", "'")) try: self._process = subprocess.Popen( cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT) # Emit the output of this command as info level logging. def log_stdout(): line = self._process.stdout.readline() while line: # Remove newline via rstrip() to not print an empty line line = self._process.stdout.readline() t = threading.Thread(target=log_stdout) t.daemon = True t.start() 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 = '' 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, appendix=None): return '/'.join([ repository, group_id.replace('.', '/'), artifact_id, version, cls.jar_name(artifact_id, version, classifier, appendix) ])
[docs] @classmethod def path_to_beam_jar(cls, gradle_target, appendix=None, version=beam_version): 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, version.replace('.dev', ''), classifier='SNAPSHOT', appendix=appendix)) if os.path.exists(local_path):'Using pre-built snapshot at %s', local_path) return local_path elif '.dev' in 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, version, cls.APACHE_REPOSITORY, appendix=appendix)
[docs] @classmethod def local_jar(cls, url, cache_dir=None): if cache_dir is None: cache_dir = cls.JAR_CACHE # TODO: Verify checksum? if os.path.exists(url): return url else: cached_jar = os.path.join(cache_dir, os.path.basename(url)) if os.path.exists(cached_jar):'Using cached job server jar from %s' % url) else:'Downloading job server jar from %s' % url) if not os.path.exists(cache_dir): os.makedirs(cache_dir) # 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