synapse-product/synapse/app/_base.py
Jorik Schellekens 38a6d3eea7
Add basic opentracing support (#5544)
* Configure and initialise tracer

Includes config options for the tracer and sets up JaegerClient.

* Scope manager using LogContexts

We piggy-back our tracer scopes by using log context.
The current log context gives us the current scope. If new scope is
created we create a stack of scopes in the context.

* jaeger is a dependency now

* Carrier inject and extraction for Twisted Headers

* Trace federation requests on the way in and out.

The span is created in _started_processing and closed in
_finished_processing because we need a meaningful log context.

* Create logcontext for new scope.

Instead of having a stack of scopes in a logcontext we create a new
context for a new scope if the current logcontext already has a scope.

* Remove scope from logcontext if logcontext is top level

* Disable tracer if not configured

* typo

* Remove dependence on jaeger internals

* bools

* Set service name

* :Explicitely state that the tracer is disabled

* Black is the new black

* Newsfile

* Code style

* Use the new config setup.

* Generate config.

* Copyright

* Rename config to opentracing

* Remove user whitelisting

* Empty whitelist by default

* User ConfigError instead of RuntimeError

* Use isinstance

* Use tag constants for opentracing.

* Remove debug comment and no need to explicitely record error

* Two errors a "s(c)entry"

* Docstrings!

* Remove debugging brainslip

* Homeserver Whitlisting

* Better opentracing config comment

* linting

* Inclue worker name in service_name

* Make opentracing an optional dependency

* Neater config retreival

* Clean up dummy tags

* Instantiate tracing as object instead of global class

* Inlcude opentracing as a homeserver member.

* Thread opentracing to the request level

* Reference opetnracing through hs

* Instantiate dummy opentracin g for tests.

* About to revert, just keeping the unfinished changes just in case

* Revert back to global state, commit number:

9ce4a3d9067bf9889b86c360c05ac88618b85c4f

* Use class level methods in tracerutils

* Start and stop requests spans in a place where we
have access to the authenticated entity

* Seen it, isort it

* Make sure to close the active span.

* I'm getting black and blue from this.

* Logger formatting

Co-Authored-By: Erik Johnston <erik@matrix.org>

* Outdated comment

* Import opentracing at the top

* Return a contextmanager

* Start tracing client requests from the servlet

* Return noop context manager if not tracing

* Explicitely say that these are federation requests

* Include servlet name in client requests

* Use context manager

* Move opentracing to logging/

* Seen it, isort it again!

* Ignore twisted return exceptions on context exit

* Escape the scope

* Scopes should be entered to make them useful.

* Nicer decorator names

* Just one init, init?

* Don't need to close something that isn't open

* Docs make you smarter
2019-07-11 10:36:03 +01:00

379 lines
12 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2017 New Vector Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import gc
import logging
import signal
import sys
import traceback
from daemonize import Daemonize
from twisted.internet import defer, error, reactor
from twisted.protocols.tls import TLSMemoryBIOFactory
import synapse
from synapse.app import check_bind_error
from synapse.crypto import context_factory
from synapse.logging.context import PreserveLoggingContext
from synapse.util.async_helpers import Linearizer
from synapse.util.rlimit import change_resource_limit
from synapse.util.versionstring import get_version_string
logger = logging.getLogger(__name__)
_sighup_callbacks = []
def register_sighup(func):
"""
Register a function to be called when a SIGHUP occurs.
Args:
func (function): Function to be called when sent a SIGHUP signal.
Will be called with a single argument, the homeserver.
"""
_sighup_callbacks.append(func)
def start_worker_reactor(appname, config):
""" Run the reactor in the main process
Daemonizes if necessary, and then configures some resources, before starting
the reactor. Pulls configuration from the 'worker' settings in 'config'.
Args:
appname (str): application name which will be sent to syslog
config (synapse.config.Config): config object
"""
logger = logging.getLogger(config.worker_app)
start_reactor(
appname,
soft_file_limit=config.soft_file_limit,
gc_thresholds=config.gc_thresholds,
pid_file=config.worker_pid_file,
daemonize=config.worker_daemonize,
print_pidfile=config.print_pidfile,
logger=logger,
)
def start_reactor(
appname, soft_file_limit, gc_thresholds, pid_file, daemonize, print_pidfile, logger
):
""" Run the reactor in the main process
Daemonizes if necessary, and then configures some resources, before starting
the reactor
Args:
appname (str): application name which will be sent to syslog
soft_file_limit (int):
gc_thresholds:
pid_file (str): name of pid file to write to if daemonize is True
daemonize (bool): true to run the reactor in a background process
print_pidfile (bool): whether to print the pid file, if daemonize is True
logger (logging.Logger): logger instance to pass to Daemonize
"""
install_dns_limiter(reactor)
def run():
logger.info("Running")
change_resource_limit(soft_file_limit)
if gc_thresholds:
gc.set_threshold(*gc_thresholds)
reactor.run()
# make sure that we run the reactor with the sentinel log context,
# otherwise other PreserveLoggingContext instances will get confused
# and complain when they see the logcontext arbitrarily swapping
# between the sentinel and `run` logcontexts.
#
# We also need to drop the logcontext before forking if we're daemonizing,
# otherwise the cputime metrics get confused about the per-thread resource usage
# appearing to go backwards.
with PreserveLoggingContext():
if daemonize:
if print_pidfile:
print(pid_file)
daemon = Daemonize(
app=appname,
pid=pid_file,
action=run,
auto_close_fds=False,
verbose=True,
logger=logger,
)
daemon.start()
else:
run()
def quit_with_error(error_string):
message_lines = error_string.split("\n")
line_length = max([len(l) for l in message_lines if len(l) < 80]) + 2
sys.stderr.write("*" * line_length + "\n")
for line in message_lines:
sys.stderr.write(" %s\n" % (line.rstrip(),))
sys.stderr.write("*" * line_length + "\n")
sys.exit(1)
def listen_metrics(bind_addresses, port):
"""
Start Prometheus metrics server.
"""
from synapse.metrics import RegistryProxy
from prometheus_client import start_http_server
for host in bind_addresses:
logger.info("Starting metrics listener on %s:%d", host, port)
start_http_server(port, addr=host, registry=RegistryProxy)
def listen_tcp(bind_addresses, port, factory, reactor=reactor, backlog=50):
"""
Create a TCP socket for a port and several addresses
Returns:
list[twisted.internet.tcp.Port]: listening for TCP connections
"""
r = []
for address in bind_addresses:
try:
r.append(reactor.listenTCP(port, factory, backlog, address))
except error.CannotListenError as e:
check_bind_error(e, address, bind_addresses)
return r
def listen_ssl(
bind_addresses, port, factory, context_factory, reactor=reactor, backlog=50
):
"""
Create an TLS-over-TCP socket for a port and several addresses
Returns:
list of twisted.internet.tcp.Port listening for TLS connections
"""
r = []
for address in bind_addresses:
try:
r.append(
reactor.listenSSL(port, factory, context_factory, backlog, address)
)
except error.CannotListenError as e:
check_bind_error(e, address, bind_addresses)
return r
def refresh_certificate(hs):
"""
Refresh the TLS certificates that Synapse is using by re-reading them from
disk and updating the TLS context factories to use them.
"""
if not hs.config.has_tls_listener():
# attempt to reload the certs for the good of the tls_fingerprints
hs.config.read_certificate_from_disk(require_cert_and_key=False)
return
hs.config.read_certificate_from_disk(require_cert_and_key=True)
hs.tls_server_context_factory = context_factory.ServerContextFactory(hs.config)
if hs._listening_services:
logger.info("Updating context factories...")
for i in hs._listening_services:
# When you listenSSL, it doesn't make an SSL port but a TCP one with
# a TLS wrapping factory around the factory you actually want to get
# requests. This factory attribute is public but missing from
# Twisted's documentation.
if isinstance(i.factory, TLSMemoryBIOFactory):
addr = i.getHost()
logger.info(
"Replacing TLS context factory on [%s]:%i", addr.host, addr.port
)
# We want to replace TLS factories with a new one, with the new
# TLS configuration. We do this by reaching in and pulling out
# the wrappedFactory, and then re-wrapping it.
i.factory = TLSMemoryBIOFactory(
hs.tls_server_context_factory, False, i.factory.wrappedFactory
)
logger.info("Context factories updated.")
def start(hs, listeners=None):
"""
Start a Synapse server or worker.
Args:
hs (synapse.server.HomeServer)
listeners (list[dict]): Listener configuration ('listeners' in homeserver.yaml)
"""
try:
# Set up the SIGHUP machinery.
if hasattr(signal, "SIGHUP"):
def handle_sighup(*args, **kwargs):
for i in _sighup_callbacks:
i(hs)
signal.signal(signal.SIGHUP, handle_sighup)
register_sighup(refresh_certificate)
# Load the certificate from disk.
refresh_certificate(hs)
# Start the tracer
synapse.logging.opentracing.init_tracer(hs.config)
# It is now safe to start your Synapse.
hs.start_listening(listeners)
hs.get_datastore().start_profiling()
setup_sentry(hs)
except Exception:
traceback.print_exc(file=sys.stderr)
reactor = hs.get_reactor()
if reactor.running:
reactor.stop()
sys.exit(1)
def setup_sentry(hs):
"""Enable sentry integration, if enabled in configuration
Args:
hs (synapse.server.HomeServer)
"""
if not hs.config.sentry_enabled:
return
import sentry_sdk
sentry_sdk.init(dsn=hs.config.sentry_dsn, release=get_version_string(synapse))
# We set some default tags that give some context to this instance
with sentry_sdk.configure_scope() as scope:
scope.set_tag("matrix_server_name", hs.config.server_name)
app = hs.config.worker_app if hs.config.worker_app else "synapse.app.homeserver"
name = hs.config.worker_name if hs.config.worker_name else "master"
scope.set_tag("worker_app", app)
scope.set_tag("worker_name", name)
def install_dns_limiter(reactor, max_dns_requests_in_flight=100):
"""Replaces the resolver with one that limits the number of in flight DNS
requests.
This is to workaround https://twistedmatrix.com/trac/ticket/9620, where we
can run out of file descriptors and infinite loop if we attempt to do too
many DNS queries at once
"""
new_resolver = _LimitedHostnameResolver(
reactor.nameResolver, max_dns_requests_in_flight
)
reactor.installNameResolver(new_resolver)
class _LimitedHostnameResolver(object):
"""Wraps a IHostnameResolver, limiting the number of in-flight DNS lookups.
"""
def __init__(self, resolver, max_dns_requests_in_flight):
self._resolver = resolver
self._limiter = Linearizer(
name="dns_client_limiter", max_count=max_dns_requests_in_flight
)
def resolveHostName(
self,
resolutionReceiver,
hostName,
portNumber=0,
addressTypes=None,
transportSemantics="TCP",
):
# We need this function to return `resolutionReceiver` so we do all the
# actual logic involving deferreds in a separate function.
# even though this is happening within the depths of twisted, we need to drop
# our logcontext before starting _resolve, otherwise: (a) _resolve will drop
# the logcontext if it returns an incomplete deferred; (b) _resolve will
# call the resolutionReceiver *with* a logcontext, which it won't be expecting.
with PreserveLoggingContext():
self._resolve(
resolutionReceiver,
hostName,
portNumber,
addressTypes,
transportSemantics,
)
return resolutionReceiver
@defer.inlineCallbacks
def _resolve(
self,
resolutionReceiver,
hostName,
portNumber=0,
addressTypes=None,
transportSemantics="TCP",
):
with (yield self._limiter.queue(())):
# resolveHostName doesn't return a Deferred, so we need to hook into
# the receiver interface to get told when resolution has finished.
deferred = defer.Deferred()
receiver = _DeferredResolutionReceiver(resolutionReceiver, deferred)
self._resolver.resolveHostName(
receiver, hostName, portNumber, addressTypes, transportSemantics
)
yield deferred
class _DeferredResolutionReceiver(object):
"""Wraps a IResolutionReceiver and simply resolves the given deferred when
resolution is complete
"""
def __init__(self, receiver, deferred):
self._receiver = receiver
self._deferred = deferred
def resolutionBegan(self, resolutionInProgress):
self._receiver.resolutionBegan(resolutionInProgress)
def addressResolved(self, address):
self._receiver.addressResolved(address)
def resolutionComplete(self):
self._deferred.callback(())
self._receiver.resolutionComplete()