log_daemon_common.py revision 5d122a264d9cfeb1ba2fa6eae4a49f1a09d486f3 
1from __future__ import print_function
2
3import sys
4from logging import handlers
5
6import common
7
8from chromite.lib import cros_logging as logging
9from infra_libs import ts_mon
10
11
12def RunMatchers(stream, matchers):
13    """Parses lines of |stream| using patterns and emitters from |matchers|
14
15    @param stream: A file object to read from.
16    @param matchers: A list of pairs of (matcher, emitter), where matcher is a
17        regex and emitter is a function called when the regex matches.
18    """
19    # The input might terminate if the log gets rotated. Make sure that Monarch
20    # flushes any pending metrics before quitting.
21    try:
22        for line in iter(stream.readline, ''):
23            for matcher, emitter in matchers:
24                m = matcher.match(line)
25                if m:
26                    logging.debug('Emitting %s for input "%s"',
27                                  emitter.__name__, line.strip())
28                    emitter(m)
29    finally:
30        ts_mon.close()
31        ts_mon.flush()
32
33
34def SetupLogging(args):
35    """Sets up logging based on the parsed arguments."""
36    # Set up logging.
37    root = logging.getLogger()
38    if args.output_logfile:
39        handler = handlers.RotatingFileHandler(
40            args.output_logfile, maxBytes=10**6, backupCount=5)
41        root.addHandler(handler)
42    else:
43        root.addHandler(logging.StreamHandler(sys.stdout))
44    root.setLevel(logging.DEBUG)
45