ui: manage logger instances and event filtering by core ui
The setup code in blackbox needs more tweaks since it has lots of black
magics. I'll fix them by follow-up patches.
To be clear, the goal of this series is to provide a proper way for command
server to install its own logger. I need it to debug in-memory repository
cache.
# logtoprocess.py - send ui.log() data to a subprocess
#
# Copyright 2016 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""send ui.log() data to a subprocess (EXPERIMENTAL)
This extension lets you specify a shell command per ui.log() event,
sending all remaining arguments to as environment variables to that command.
Positional arguments construct a log message, which is passed in the `MSG1`
environment variables. Each keyword argument is set as a `OPT_UPPERCASE_KEY`
variable (so the key is uppercased, and prefixed with `OPT_`). The original
event name is passed in the `EVENT` environment variable, and the process ID
of mercurial is given in `HGPID`.
So given a call `ui.log('foo', 'bar %s\n', 'baz', spam='eggs'), a script
configured for the `foo` event can expect an environment with `MSG1=bar baz`,
and `OPT_SPAM=eggs`.
Scripts are configured in the `[logtoprocess]` section, each key an event name.
For example::
[logtoprocess]
commandexception = echo "$MSG1" > /var/log/mercurial_exceptions.log
would log the warning message and traceback of any failed command dispatch.
Scripts are run asynchronously as detached daemon processes; mercurial will
not ensure that they exit cleanly.
"""
from __future__ import absolute_import
import os
from mercurial import (
pycompat,
)
from mercurial.utils import (
procutil,
)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
class processlogger(object):
"""Map log events to external commands
Arguments are passed on as environment variables.
"""
def __init__(self, ui):
self._scripts = dict(ui.configitems(b'logtoprocess'))
def tracked(self, event):
return bool(self._scripts.get(event))
def log(self, ui, event, msg, opts):
script = self._scripts[event]
env = {
b'EVENT': event,
b'HGPID': os.getpid(),
b'MSG1': msg[0] % msg[1:],
}
# keyword arguments get prefixed with OPT_ and uppercased
env.update((b'OPT_%s' % key.upper(), value)
for key, value in pycompat.byteskwargs(opts).items())
fullenv = procutil.shellenviron(env)
procutil.runbgcommand(script, fullenv, shell=True)
def uipopulate(ui):
ui.setlogger(b'logtoprocess', processlogger(ui))