root / lib / logger.py @ 74b4217d
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# Copyright (C) 2006, 2007 Google Inc.
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 2 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful, but
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# WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301, USA.
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"""Logging for Ganeti
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This module abstracts the logging handling away from the rest of the
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Ganeti code. It offers some utility functions for easy logging.
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"""
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# pylint: disable-msg=W0603,C0103
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import sys |
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import logging |
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import os, os.path |
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from ganeti import constants |
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_program = '(unknown)'
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_errlog = None
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_inflog = None
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_dbglog = None
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_stdout = None
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_stderr = None
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_debug = False
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def _SetDestination(name, filename, stream=None): |
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"""Configure the destination for a given logger
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This function configures the logging destination for a given loger.
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Parameters:
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- name: the logger name
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- filename: if not empty, log messages will be written (also) to this file
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- stream: if not none, log messages will be output (also) to this stream
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Returns:
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- the logger identified by the `name` argument
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"""
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ret = logging.getLogger(name) |
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if filename:
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fmtr = logging.Formatter('%(asctime)s %(message)s')
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hdlr = logging.FileHandler(filename) |
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hdlr.setFormatter(fmtr) |
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ret.addHandler(hdlr) |
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if stream:
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if name in ('error', 'info', 'debug'): |
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fmtr = logging.Formatter('%(asctime)s %(message)s')
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else:
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fmtr = logging.Formatter('%(message)s')
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hdlr = logging.StreamHandler(stream) |
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hdlr.setFormatter(fmtr) |
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ret.addHandler(hdlr) |
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ret.setLevel(logging.INFO) |
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return ret
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def _GenericSetup(program, errfile, inffile, dbgfile, |
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twisted_workaround=False):
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"""Configure logging based on arguments
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Arguments:
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- name of program
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- error log filename
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- info log filename
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- debug log filename
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- twisted_workaround: if true, emit all messages to stderr
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"""
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global _program
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global _errlog
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global _inflog
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global _dbglog
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global _stdout
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global _stderr
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_program = program |
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if twisted_workaround:
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_errlog = _SetDestination('error', None, sys.stderr) |
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_inflog = _SetDestination('info', None, sys.stderr) |
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_dbglog = _SetDestination('debug', None, sys.stderr) |
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else:
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_errlog = _SetDestination('error', errfile)
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_inflog = _SetDestination('info', inffile)
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_dbglog = _SetDestination('debug', dbgfile)
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_stdout = _SetDestination('user', None, sys.stdout) |
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_stderr = _SetDestination('stderr', None, sys.stderr) |
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def SetupLogging(twisted_workaround=False, debug=False, program='ganeti'): |
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"""Setup logging for ganeti
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On failure, a check is made whether process is run by root or not,
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and an appropriate error message is printed on stderr, then process
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exits.
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This function is just a wraper over `_GenericSetup()` using specific
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arguments.
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Parameter:
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twisted_workaround: passed to `_GenericSetup()`
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"""
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try:
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_GenericSetup(program, |
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os.path.join(constants.LOG_DIR, "errors"),
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os.path.join(constants.LOG_DIR, "info"),
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os.path.join(constants.LOG_DIR, "debug"),
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twisted_workaround) |
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except IOError: |
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# The major reason to end up here is that we're being run as a
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# non-root user. We might also get here if xen has not been
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# installed properly. This is not the correct place to enforce
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# being run by root; nevertheless, here makes sense because here
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# is where we first notice it.
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if os.getuid() != 0: |
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sys.stderr.write('This program must be run by the superuser.\n')
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else:
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sys.stderr.write('Unable to open log files. Incomplete system?\n')
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sys.exit(2)
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global _debug
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_debug = debug |
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def _WriteEntry(log, txt): |
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"""
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Write a message to a given log.
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Splits multi-line messages up into a series of log writes, to
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keep consistent format on lines in file.
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Parameters:
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- log: the destination log
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- txt: the message
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"""
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if log is None: |
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sys.stderr.write("Logging system not initialized while processing"
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" message:\n")
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sys.stderr.write("%s\n" % txt)
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return
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lines = txt.split('\n')
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spaces = ' ' * len(_program) + '| ' |
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lines = ([ _program + ': ' + lines[0] ] + |
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map(lambda a: spaces + a, lines[1:])) |
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for line in lines: |
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log.log(logging.INFO, line) |
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def ToStdout(txt): |
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"""Write a message to stdout only, bypassing the logging system
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Parameters:
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- txt: the message
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"""
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sys.stdout.write(txt + '\n')
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sys.stdout.flush() |
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def ToStderr(txt): |
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"""Write a message to stderr only, bypassing the logging system
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Parameters:
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- txt: the message
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"""
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sys.stderr.write(txt + '\n')
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sys.stderr.flush() |
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def Error(txt): |
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"""Write a message to our error log
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Parameters:
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- dbg: if true, the message will also be output to stderr
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- txt: the log message
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"""
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_WriteEntry(_errlog, txt) |
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sys.stderr.write(txt + '\n')
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def Info(txt): |
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"""Write a message to our general messages log
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If the global debug flag is true, the log message will also be
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output to stderr.
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Parameters:
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- txt: the log message
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"""
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_WriteEntry(_inflog, txt) |
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if _debug:
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_WriteEntry(_stderr, txt) |
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def Debug(txt): |
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"""Write a message to the debug log
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If the global debug flag is true, the log message will also be
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output to stderr.
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Parameters:
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- txt: the log message
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"""
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_WriteEntry(_dbglog, txt) |
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if _debug:
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_WriteEntry(_stderr, txt) |