def start(self, application):
"""
Initialize the global logging system for the given application.
If a custom logger was specified on the command line it will be used.
If not, and an L{logger.ILogObserver} or legacy L{log.ILogObserver}
component has been set on C{application}, then it will be used as the
log observer. Otherwise a log observer will be created based on the
command line options for built-in loggers (e.g. C{--logfile}).
@param application: The application on which to check for an
L{logger.ILogObserver} or legacy L{log.ILogObserver}.
@type application: L{twisted.python.components.Componentized}
"""
if self._observerFactory is not None:
observer = self._observerFactory()
else:
observer = application.getComponent(logger.ILogObserver, None)
if observer is None:
# If there's no new ILogObserver, try the legacy one
observer = application.getComponent(log.ILogObserver, None)
if observer is None:
observer = self._getLogObserver()
self._observer = observer
if logger.ILogObserver.providedBy(self._observer):
observers = [self._observer]
elif log.ILogObserver.providedBy(self._observer):
observers = [logger.LegacyLogObserverWrapper(self._observer)]
else:
warnings.warn(
(
"Passing a logger factory which makes log observers which do "
"not implement twisted.logger.ILogObserver or "
"twisted.python.log.ILogObserver to "
"twisted.application.app.AppLogger was deprecated in "
"Twisted 16.2. Please use a factory that produces "
"twisted.logger.ILogObserver (or the legacy "
"twisted.python.log.ILogObserver) implementing objects "
"instead."
),
DeprecationWarning,
stacklevel=2,
)
observers = [logger.LegacyLogObserverWrapper(self._observer)]
logger.globalLogBeginner.beginLoggingTo(observers)
self._initialLog()
def _startLoggingWithObserver(observer, setStdout=1):
"""Replacement for `t.p.log.startLoggingWithObserver`.
When `twistd` starts in 16.0 it initialises the legacy logging system.
Intercept this to DTRT with either a modern or legacy observer.
In Xenial (with Twisted 16.0) `observer` is probably a legacy observer,
like twisted.python.log.FileLogObserver, but we should check if it's
modern. In either case we should call through to the `globalLogBeginner`
ourselves. In Yakkety (with Twisted 16.4) this function will not be
called; `t.application.app.AppLogger` does the right thing already.
"""
if not twistedModern.ILogObserver.providedBy(observer):
observer = twistedModern.LegacyLogObserverWrapper(observer)
twistedModern.globalLogBeginner.beginLoggingTo(
[observer], discardBuffer=False, redirectStandardIO=bool(setStdout))
