[ovs-dev] [PATCH 1/1] Python Logging Formatting Improvements
Dave Tucker
dave at dtucker.co.uk
Thu Mar 27 14:28:29 UTC 2014
The Open vSwitch daemons written in C support user-configured logging
patterns as described in ovs-appctl(8). This commit adds this capability
to the daemons written in Python.
- Add a '__log_patterns' attribute to the Vlog class
- Populate this using the default patterns in ovs-appctl(8)
- Add a '__start_time' attribute to the Vlog class to support '%r'
- Update the '_log' method to build the log message according to the
pattern
- Add a 'set_pattern' method to allow the default patterns to be changed
- Update 'set_levels_from_string' to support setting the pattern from a
string
- Remove milliseconds from date/time format as not available in strftime
Signed-off-by: Dave Tucker <dave at dtucker.co.uk>
---
python/ovs/vlog.py | 121 +++++++++++++++++++++++++++++++++++++++++++++++------
tests/vlog.at | 12 +++++-
2 files changed, 119 insertions(+), 14 deletions(-)
diff --git a/python/ovs/vlog.py b/python/ovs/vlog.py
index 478f08e..523d7d7 100644
--- a/python/ovs/vlog.py
+++ b/python/ovs/vlog.py
@@ -24,7 +24,15 @@ import ovs.dirs
import ovs.unixctl
import ovs.util
+DEFAULT_FILE_PATTERN = "%D{%Y-%m-%dT%H:%M:%SZ}|%0N|%0c|%0p|%0m"
+DEFAULT_SYSLOG_PATTERN = "%0N|%0c|%0p|%0m"
+
FACILITIES = {"console": "info", "file": "info", "syslog": "info"}
+PATTERNS = {
+ "console": DEFAULT_FILE_PATTERN,
+ "file": DEFAULT_FILE_PATTERN,
+ "syslog": DEFAULT_SYSLOG_PATTERN
+}
LEVELS = {
"dbg": logging.DEBUG,
"info": logging.INFO,
@@ -42,9 +50,11 @@ def get_level(level_str):
class Vlog:
__inited = False
__msg_num = 0
+ __start_time = 0
__mfl = {} # Module -> facility -> level
__log_file = None
__file_handler = None
+ __log_patterns = PATTERNS
def __init__(self, name):
"""Creates a new Vlog object representing a module called 'name'. The
@@ -60,22 +70,86 @@ class Vlog:
if not Vlog.__inited:
return
- dt = datetime.datetime.utcnow();
- now = dt.strftime("%Y-%m-%dT%H:%M:%S.%%03iZ") % (dt.microsecond/1000)
- syslog_message = ("%s|%s|%s|%s"
- % (Vlog.__msg_num, self.name, level, message))
-
- level = LEVELS.get(level.lower(), logging.DEBUG)
+ level_num = LEVELS.get(level.lower(), logging.DEBUG)
+ msg_num = Vlog.__msg_num
Vlog.__msg_num += 1
for f, f_level in Vlog.__mfl[self.name].iteritems():
f_level = LEVELS.get(f_level, logging.CRITICAL)
- if level >= f_level:
- if f == "syslog":
- message = "ovs|" + syslog_message
- else:
- message = "%s|%s" % (now, syslog_message)
- logging.getLogger(f).log(level, message, **kwargs)
+ if level_num >= f_level:
+ msg = self._build_message(message, f, level, msg_num)
+ logging.getLogger(f).log(level_num, msg, **kwargs)
+
+ def _build_message(self, message, facility, level, msg_num):
+ pattern = self.__log_patterns[facility]
+ tmp = pattern
+
+ tmp = self._format_time(tmp)
+
+ matches = re.findall("(%-?[0]?[0-9]?[AcmNnpPrtT])", tmp)
+ for m in matches:
+ if "A" in m:
+ #ToDo: Not sure how we can get the application name
+ tmp = self._format_field(tmp, m, "")
+ elif "c" in m:
+ tmp = self._format_field(tmp, m, self.name)
+ elif "m" in m:
+ tmp = self._format_field(tmp, m, message)
+ elif "N" in m:
+ tmp = self._format_field(tmp, m, str(msg_num))
+ elif "n" in m:
+ tmp = re.sub(m, "\n", tmp)
+ elif "p" in m:
+ tmp = self._format_field(tmp, m, level.upper())
+ elif "P" in m:
+ #ToDo: Not sure how we can get the process ID
+ self._format_field(tmp, m, "")
+ elif "r" in m:
+ now = datetime.datetime.utcnow()
+ delta = now - self.__start_time
+ ms = int(delta.microseconds * 0.001)
+ tmp = self._format_field(tmp, m, str(ms))
+ elif "t" in m:
+ #ToDo: Not sure how we can get the sub-process name
+ tmp = self._format_field(tmp, m, "")
+ elif "T" in m:
+ #ToDo: Not sure how we can get the sub-process name
+ tmp = self._format_field(tmp, m, "")
+ return tmp
+
+ def _format_field(self, tmp, match, replace):
+ formatting = re.compile("%(0)?([1-9])?")
+ matches = formatting.match(match)
+ # Do we need to apply padding?
+ if not matches.group(1):
+ replace = replace.center(len(replace)+2)
+ # Does the field have a minimum width
+ if matches.group(2):
+ min_width = int(matches.group(2))
+ if len(replace) < min_width:
+ replace = replace.center(min_width)
+ return re.sub(match, replace, tmp)
+
+ def _format_time(self, tmp):
+ date_regex = re.compile('(%([dD])(\{(.*)\})?)')
+ match = date_regex.search(tmp)
+
+ if match is None:
+ return tmp
+
+ # UTC date or Local TZ?
+ if match.group(2) == "d":
+ now = datetime.datetime.now()
+ elif match.group(2) == "D":
+ now = datetime.datetime.utcnow()
+
+ # Custom format or ISO format?
+ if match.group(3):
+ time = datetime.date.strftime(now, match.group(4))
+ else:
+ time = datetime.datetime.isoformat(now.replace(microsecond=0))
+
+ return re.sub(match.group(1), time, tmp)
def emer(self, message, **kwargs):
self.__log("EMER", message, **kwargs)
@@ -130,6 +204,7 @@ class Vlog:
return
Vlog.__inited = True
+ Vlog.__start_time = datetime.datetime.utcnow()
logging.raiseExceptions = False
Vlog.__log_file = log_file
for f in FACILITIES:
@@ -191,12 +266,31 @@ class Vlog:
Vlog.__mfl[m][f] = level
@staticmethod
+ def set_pattern(facility, pattern):
+ """ Sets the log pattern of the 'facility' to 'pattern' """
+ facility = facility.lower()
+ Vlog.__log_patterns[facility] = pattern
+
+ @staticmethod
def set_levels_from_string(s):
module = None
level = None
facility = None
- for word in [w.lower() for w in re.split('[ :]', s)]:
+ words = re.split('[ :]', s)
+ if words[0] == "pattern":
+ try:
+ if words[1] in FACILITIES and words[2]:
+ segments = [words[i] for i in range(2, len(words))]
+ pattern = "".join(segments)
+ Vlog.set_pattern(words[1], pattern)
+ return
+ else:
+ return "Facility %s does not exist" % words[1]
+ except IndexError:
+ return "Please supply a valid pattern and facility"
+
+ for word in [w.lower() for w in words]:
if word == "any":
pass
elif word in FACILITIES:
@@ -260,6 +354,7 @@ class Vlog:
def _unixctl_vlog_list(conn, unused_argv, unused_aux):
conn.reply(Vlog.get_levels())
+
def add_args(parser):
"""Adds vlog related options to 'parser', an ArgumentParser object. The
resulting arguments parsed by 'parser' should be passed to handle_args."""
diff --git a/tests/vlog.at b/tests/vlog.at
index 35336ce..eb70cdb 100644
--- a/tests/vlog.at
+++ b/tests/vlog.at
@@ -9,7 +9,7 @@ AT_CHECK([$PYTHON $srcdir/test-vlog.py --log-file log_file \
AT_CHECK([diff log_file stderr_log])
-AT_CHECK([sed -e 's/.*-.*-.*T..:..:..\....Z|//' \
+AT_CHECK([sed -e 's/.*-.*-.*T..:..:..Z|//' \
-e 's/File ".*", line [[0-9]][[0-9]]*,/File <name>, line <number>,/' \
stderr_log], [0], [dnl
0|module_0|EMER|emergency
@@ -225,4 +225,14 @@ stream info info dbg
test-unixctl info info dbg
unixctl_server info info dbg
])
+
+AT_CHECK([APPCTL -t test-unixctl.py vlog/set pattern], [0],
+ [Please supply a valid pattern and facility
+])
+AT_CHECK([APPCTL -t test-unixctl.py vlog/set pattern:nonexistent], [0],
+ [Facility nonexistent does not exist
+])
+AT_CHECK([APPCTL -t test-unixctl.py vlog/set pattern:file:'I<3OVS|%m'])
+AT_CHECK([APPCTL -t test-unixctl.py log patterntest])
+AT_CHECK([grep -q 'I<3OVS' log])
AT_CLEANUP
--
1.9.1
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