#
# Copyright 2012 Facebook
#
# 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.
"""Logging support for Tornado.
Tornado uses three logger streams:
* ``tornado.access``: Per-request logging for Tornado's HTTP servers (and
potentially other servers in the future)
* ``tornado.application``: Logging of errors from application code (i.e.
uncaught exceptions from callbacks)
* ``tornado.general``: General-purpose logging, including any errors
or warnings from Tornado itself.
These streams may be configured independently using the standard library's
`logging` module. For example, you may wish to send ``tornado.access`` logs
to a separate file for analysis.
"""
from __future__ import absolute_import, division, print_function
import logging
import logging.handlers
import sys
from tornado.escape import _unicode
from tornado.util import unicode_type, basestring_type
try:
import colorama
except ImportError:
colorama = None
try:
import curses # type: ignore
except ImportError:
curses = None
# Logger objects for internal tornado use
access_log = logging.getLogger("tornado.access")
app_log = logging.getLogger("tornado.application")
gen_log = logging.getLogger("tornado.general")
def _stderr_supports_color():
try:
if hasattr(sys.stderr, 'isatty') and sys.stderr.isatty():
if curses:
curses.setupterm()
if curses.tigetnum("colors") > 0:
return True
elif colorama:
if sys.stderr is getattr(colorama.initialise, 'wrapped_stderr',
object()):
return True
except Exception:
# Very broad exception handling because it's always better to
# fall back to non-colored logs than to break at startup.
pass
return False
def _safe_unicode(s):
try:
return _unicode(s)
except UnicodeDecodeError:
return repr(s)
class LogFormatter(logging.Formatter):
"""Log formatter used in Tornado.
Key features of this formatter are:
* Color support when logging to a terminal that supports it.
* Timestamps on every log line.
* Robust against str/bytes encoding problems.
This formatter is enabled automatically by
`tornado.options.parse_command_line` or `tornado.options.parse_config_file`
(unless ``--logging=none`` is used).
Color support on Windows versions that do not support ANSI color codes is
enabled by use of the colorama__ library. Applications that wish to use
this must first initialize colorama with a call to ``colorama.init``.
See the colorama documentation for details.
__ https://pypi.python.org/pypi/colorama
.. versionchanged:: 4.5
Added support for ``colorama``. Changed the constructor
signature to be compatible with `logging.config.dictConfig`.
"""
DEFAULT_FORMAT = \
'%(color)s[%(levelname)1.1s %(asctime)s %(module)s:%(lineno)d]%(end_color)s %(message)s'
DEFAULT_DATE_FORMAT = '%y%m%d %H:%M:%S'
DEFAULT_COLORS = {
logging.DEBUG: 4, # Blue
logging.INFO: 2, # Green
logging.WARNING: 3, # Yellow
logging.ERROR: 1, # Red
}
def __init__(self, fmt=DEFAULT_FORMAT, datefmt=DEFAULT_DATE_FORMAT,
style='%', color=True, colors=DEFAULT_COLORS):
r"""
:arg bool color: Enables color support.
:arg str fmt: Log message format.
It will be applied to the attributes dict of log records. The
text between ``%(color)s`` and ``%(end_color)s`` will be colored
depending on the level if color support is on.
:arg dict colors: color mappings from logging level to terminal color
code
:arg str datefmt: Datetime format.
Used for formatting ``(asctime)`` placeholder in ``prefix_fmt``.
.. versionchanged:: 3.2
Added ``fmt`` and ``datefmt`` arguments.
"""
logging.Formatter.__init__(self, datefmt=datefmt)
self._fmt = fmt
self._colors = {}
if color and _stderr_supports_color():
if curses is not None:
# The curses module has some str/bytes confusion in
# python3. Until version 3.2.3, most methods return
# bytes, but only accept strings. In addition, we want to
# output these strings with the logging module, which
# works with unicode strings. The explicit calls to
# unicode() below are harmless in python2 but will do the
# right conversion in python 3.
fg_color = (curses.tigetstr("setaf") or
curses.tigetstr("setf") or "")
if (3, 0) < sys.version_info < (3, 2, 3):
fg_color = unicode_type(fg_color, "ascii")
for levelno, code in colors.items():
self._colors[levelno] = unicode_type(curses.tparm(fg_color, code), "ascii")
self._normal = unicode_type(curses.tigetstr("sgr0"), "ascii")
else:
# If curses is not present (currently we'll only get here for
# colorama on windows), assume hard-coded ANSI color codes.
for levelno, code in colors.items():
self._colors[levelno] = '\033[2;3%dm' % code
self._normal = '\033[0m'
else:
self._normal = ''
def format(self, record):
try:
message = record.getMessage()
assert isinstance(message, basestring_type) # guaranteed by logging
# Encoding notes: The logging module prefers to work with character
# strings, but only enforces that log messages are instances of
# basestring. In python 2, non-ascii bytestrings will make
# their way through the logging framework until they blow up with
# an unhelpful decoding error (with this formatter it happens
# when we attach the prefix, but there are other opportunities for
# exceptions further along in the framework).
#
# If a byte string makes it this far, convert it to unicode to
# ensure it will make it out to the logs. Use repr() as a fallback
# to ensure that all byte strings can be converted successfully,
# but don't do it by default so we don't add extra quotes to ascii
# bytestrings. This is a bit of a hacky place to do this, but
# it's worth it since the encoding errors that would otherwise
# result are so useless (and tornado is fond of using utf8-encoded
# byte strings wherever possible).
record.message = _safe_unicode(message)
except Exception as e:
record.message = "Bad message (%r): %r" % (e, record.__dict__)
record.asctime = self.formatTime(record, self.datefmt)
if record.levelno in self._colors:
record.color = self._colors[record.levelno]
record.end_color = self._normal
else:
record.color = record.end_color = ''
formatted = self._fmt % record.__dict__
if record.exc_info:
if not record.exc_text:
record.exc_text = self.formatException(record.exc_info)
if record.exc_text:
# exc_text contains multiple lines. We need to _safe_unicode
# each line separately so that non-utf8 bytes don't cause
# all the newlines to turn into '\n'.
lines = [formatted.rstrip()]
lines.extend(_safe_unicode(ln) for ln in record.exc_text.split('\n'))
formatted = '\n'.join(lines)
return formatted.replace("\n", "\n ")
def enable_pretty_logging(options=None, logger=None):
"""Turns on formatted logging output as configured.
This is called automatically by `tornado.options.parse_command_line`
and `tornado.options.parse_config_file`.
"""
if options is None:
import tornado.options
options = tornado.options.options
if options.logging is None or options.logging.lower() == 'none':
return
if logger is None:
logger = logging.getLogger()
logger.setLevel(getattr(logging, options.logging.upper()))
if options.log_file_prefix:
rotate_mode = options.log_rotate_mode
if rotate_mode == 'size':
channel = logging.handlers.RotatingFileHandler(
filename=options.log_file_prefix,
maxBytes=options.log_file_max_size,
backupCount=options.log_file_num_backups)
elif rotate_mode == 'time':
channel = logging.handlers.TimedRotatingFileHandler(
filename=options.log_file_prefix,
when=options.log_rotate_when,
interval=options.log_rotate_interval,
backupCount=options.log_file_num_backups)
else:
error_message = 'The value of log_rotate_mode option should be ' +\
'"size" or "time", not "%s".' % rotate_mode
raise ValueError(error_message)
channel.setFormatter(LogFormatter(color=False))
logger.addHandler(channel)
if (options.log_to_stderr or
(options.log_to_stderr is None and not logger.handlers)):
# Set up color if we are in a tty and curses is installed
channel = logging.StreamHandler()
channel.setFormatter(LogFormatter())
logger.addHandler(channel)
def define_logging_options(options=None):
"""Add logging-related flags to ``options``.
These options are present automatically on the default options instance;
this method is only necessary if you have created your own `.OptionParser`.
.. versionadded:: 4.2
This function existed in prior versions but was broken and undocumented until 4.2.
"""
if options is None:
# late import to prevent cycle
import tornado.options
options = tornado.options.options
options.define("logging", default="info",
help=("Set the Python log level. If 'none', tornado won't touch the "
"logging configuration."),
metavar="debug|info|warning|error|none")
options.define("log_to_stderr", type=bool, default=None,
help=("Send log output to stderr (colorized if possible). "
"By default use stderr if --log_file_prefix is not set and "
"no other logging is configured."))
options.define("log_file_prefix", type=str, default=None, metavar="PATH",
help=("Path prefix for log files. "
"Note that if you are running multiple tornado processes, "
"log_file_prefix must be different for each of them (e.g. "
"include the port number)"))
options.define("log_file_max_size", type=int, default=100 * 1000 * 1000,
help="max size of log files before rollover")
options.define("log_file_num_backups", type=int, default=10,
help="number of log files to keep")
options.define("log_rotate_when", type=str, default='midnight',
help=("specify the type of TimedRotatingFileHandler interval "
"other options:('S', 'M', 'H', 'D', 'W0'-'W6')"))
options.define("log_rotate_interval", type=int, default=1,
help="The interval value of timed rotating")
options.define("log_rotate_mode", type=str, default='size',
help="The mode of rotating files(time or size)")
options.add_parse_callback(lambda: enable_pretty_logging(options))