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diff --git a/python/pacemaker/_cts/watcher.py b/python/pacemaker/_cts/watcher.py
index da3b5f12a7..55e7c33f69 100644
--- a/python/pacemaker/_cts/watcher.py
+++ b/python/pacemaker/_cts/watcher.py
@@ -1,555 +1,552 @@
"""Log searching classes for Pacemaker's Cluster Test Suite (CTS)."""
__all__ = ["LogKind", "LogWatcher"]
__copyright__ = "Copyright 2014-2024 the Pacemaker project contributors"
__license__ = "GNU General Public License version 2 or later (GPLv2+) WITHOUT ANY WARRANTY"
from enum import Enum, unique
import re
import time
import threading
from pacemaker.buildoptions import BuildOptions
from pacemaker._cts.logging import LogFactory
from pacemaker._cts.remote import RemoteFactory
LOG_WATCHER_BIN = "%s/cts-log-watcher" % BuildOptions.DAEMON_DIR
@unique
class LogKind(Enum):
"""The various kinds of log files that can be watched."""
ANY = 0
FILE = 1
REMOTE_FILE = 2
JOURNAL = 3
def __str__(self):
"""Return a printable string for a LogKind value."""
if self.value == 0:
return "any"
if self.value == 1:
return "combined syslog"
if self.value == 2:
return "remote"
return "journal"
class SearchObj:
"""
The base class for various kinds of log watchers.
Log-specific watchers need to be built on top of this one.
"""
def __init__(self, filename, host=None, name=None):
"""
Create a new SearchObj instance.
Arguments:
filename -- The log to watch
host -- The cluster node on which to watch the log
name -- A unique name to use when logging about this watch
"""
self.cache = []
self.filename = filename
self.limit = None
self.logger = LogFactory()
self.name = name
self.offset = "EOF"
self.rsh = RemoteFactory().getInstance()
if host:
self.host = host
else:
self.host = "localhost"
def __str__(self):
if self.host:
return "%s:%s" % (self.host, self.filename)
return self.filename
def log(self, args):
"""Log a message."""
message = "lw: %s: %s" % (self, args)
self.logger.log(message)
def debug(self, args):
"""Log a debug message."""
message = "lw: %s: %s" % (self, args)
self.logger.debug(message)
def harvest(self, delegate=None):
"""Collect lines from a log, optionally calling delegate when complete."""
async_task = self.harvest_async(delegate)
async_task.join()
def harvest_async(self, delegate=None):
"""
Collect lines from a log asynchronously.
Optionally, also call delegate when complete. This method must be
implemented by all subclasses.
"""
raise NotImplementedError
def end(self):
"""
Mark that a log is done being watched.
This function also resets internal data structures to the beginning
of the file. Subsequent watches will therefore start from the
beginning again.
"""
self.debug("Unsetting the limit")
self.limit = None
class FileObj(SearchObj):
"""A specialized SearchObj subclass for watching log files."""
def __init__(self, filename, host=None, name=None):
"""
Create a new FileObj instance.
Arguments:
filename -- The file to watch
host -- The cluster node on which to watch the file
name -- A unique name to use when logging about this watch
"""
SearchObj.__init__(self, filename, host, name)
self._delegate = None
self.harvest()
def async_complete(self, pid, returncode, out, err):
"""
Handle completion of an asynchronous log file read.
This function saves the output from that read for look()/look_for_all()
to process and records the current position in the journal. Future
reads will pick back up from that spot.
Arguments:
pid -- The ID of the process that did the read
returncode -- The return code of the process that did the read
out -- stdout from the file read
err -- stderr from the file read
"""
for line in out:
match = re.search(r"^CTSwatcher:Last read: (\d+)", line)
if match:
self.offset = match.group(1)
self.debug("Got %d lines, new offset: %s %r" % (len(out), self.offset, self._delegate))
elif re.search(r"^CTSwatcher:.*truncated", line):
self.log(line)
elif re.search(r"^CTSwatcher:", line):
self.debug("Got control line: %s" % line)
else:
self.cache.append(line)
if self._delegate:
self._delegate.async_complete(pid, returncode, self.cache, err)
def harvest_async(self, delegate=None):
"""
Collect lines from the log file on a single host asynchronously.
Optionally, call delegate when complete. This can be called
repeatedly, reading a chunk each time or until the end of the
log file is hit.
"""
self._delegate = delegate
self.cache = []
if self.limit and (self.offset == "EOF" or int(self.offset) > self.limit):
if self._delegate:
self._delegate.async_complete(-1, -1, [], [])
return None
return self.rsh.call_async(self.host,
"%s -t %s -p CTSwatcher: -l 200 -f %s -o %s" % (LOG_WATCHER_BIN, self.name, self.filename, self.offset),
delegate=self)
def set_end(self):
"""
Internally record where we expect to find the end of a log file.
Calls to harvest from the log file will not go any farther than
what this function records.
"""
if self.limit:
return
# pylint: disable=not-callable
(_, lines) = self.rsh(self.host,
"%s -t %s -p CTSwatcher: -l 2 -f %s -o %s" % (LOG_WATCHER_BIN, self.name, self.filename, "EOF"),
verbose=0)
for line in lines:
match = re.search(r"^CTSwatcher:Last read: (\d+)", line)
if match:
self.limit = int(match.group(1))
self.debug("Set limit to: %d" % self.limit)
class JournalObj(SearchObj):
"""A specialized SearchObj subclass for watching systemd journals."""
def __init__(self, host=None, name=None):
"""
Create a new JournalObj instance.
Arguments:
host -- The cluster node on which to watch the journal
name -- A unique name to use when logging about this watch
"""
SearchObj.__init__(self, name, host, name)
self._delegate = None
self._hit_limit = False
self.harvest()
def async_complete(self, pid, returncode, out, err):
"""
Handle completion of an asynchronous journal read.
This function saves the output from that read for look()/look_for_all()
to process and records the current position in the journal. Future
reads will pick back up from that spot.
Arguments:
pid -- The ID of the process that did the journal read
returncode -- The return code of the process that did the journal read
out -- stdout from the journal read
err -- stderr from the journal read
"""
found_cursor = False
for line in out:
match = re.search(r"^-- cursor: ([^.]+)", line)
if match:
found_cursor = True
self.offset = match.group(1).strip()
self.debug("Got %d lines, new cursor: %s" % (len(out), self.offset))
else:
self.cache.append(line)
if self.limit and not found_cursor:
self._hit_limit = True
self.debug("Got %d lines but no cursor: %s" % (len(out), self.offset))
# Get the current cursor
# pylint: disable=not-callable
(_, out) = self.rsh(self.host, "journalctl -q -n 0 --show-cursor", verbose=0)
for line in out:
match = re.search(r"^-- cursor: ([^.]+)", line)
if match:
self.offset = match.group(1).strip()
self.debug("Got %d lines, new cursor: %s" % (len(out), self.offset))
else:
self.log("Not a new cursor: %s" % line)
self.cache.append(line)
if self._delegate:
self._delegate.async_complete(pid, returncode, self.cache, err)
def harvest_async(self, delegate=None):
"""
Collect lines from the journal on a single host asynchronously.
Optionally, call delegate when complete. This can be called
repeatedly, reading a chunk each time or until the end of the journal
is hit.
"""
self._delegate = delegate
self.cache = []
# Use --lines to prevent journalctl from overflowing the Popen input buffer
if self.limit and self._hit_limit:
return None
if self.offset == "EOF":
command = "journalctl -q -n 0 --show-cursor"
elif self.limit:
command = "journalctl -q --after-cursor='%s' --until '%s' --lines=200 --show-cursor" % (self.offset, self.limit)
else:
command = "journalctl -q --after-cursor='%s' --lines=200 --show-cursor" % (self.offset)
return self.rsh.call_async(self.host, command, delegate=self)
def set_end(self):
"""
Internally record where we expect to find the end of a host's journal.
Calls to harvest from the journal will not go any farther than what
this function records.
"""
if self.limit:
return
self._hit_limit = False
# pylint: disable=not-callable
(rc, lines) = self.rsh(self.host, "date +'%Y-%m-%d %H:%M:%S'", verbose=0)
if rc == 0 and len(lines) == 1:
self.limit = lines[0].strip()
self.debug("Set limit to: %s" % self.limit)
else:
self.debug("Unable to set limit for %s because date returned %d lines with status %d"
% (self.host, len(lines), rc))
class LogWatcher:
"""
Watch a single log file or journal across multiple hosts.
Instances of this class look for lines that match given regular
expressions.
The way you use this class is as follows:
- Construct a LogWatcher object
- Call set_watch() when you want to start watching the log
- Call look() to scan the log looking for the patterns
"""
def __init__(self, log, regexes, hosts, kind=LogKind.ANY, name="Anon", timeout=10, silent=False):
"""
Create a new LogWatcher instance.
Arguments:
log -- The log file to watch
regexes -- A list of regular expressions to match against the log
hosts -- A list of cluster nodes on which to watch the log
kind -- What type of log is this object watching?
name -- A unique name to use when logging about this watch
timeout -- Default number of seconds to watch a log file at a time;
this can be overridden by the timeout= parameter to
self.look on an as-needed basis
silent -- If False, log extra information
"""
self.filename = log
self.hosts = hosts
self.kind = kind
self.name = name
self.regexes = regexes
self.unmatched = None
self.whichmatch = -1
self._cache_lock = threading.Lock()
self._file_list = []
self._line_cache = []
self._logger = LogFactory()
self._timeout = int(timeout)
# Validate our arguments. Better sooner than later ;-)
for regex in regexes:
re.compile(regex)
if not self.hosts:
raise ValueError("LogWatcher requires hosts argument")
if not self.filename:
raise ValueError("LogWatcher requires log argument")
if not silent:
for regex in self.regexes:
self._debug("Looking for regex: %s" % regex)
def _debug(self, args):
"""Log a debug message."""
message = "lw: %s: %s" % (self.name, args)
self._logger.debug(message)
def set_watch(self):
"""Mark the place to start watching the log from."""
if self.kind == LogKind.REMOTE_FILE:
for node in self.hosts:
self._file_list.append(FileObj(self.filename, node, self.name))
elif self.kind == LogKind.JOURNAL:
for node in self.hosts:
self._file_list.append(JournalObj(node, self.name))
else:
self._file_list.append(FileObj(self.filename))
def async_complete(self, pid, returncode, out, err):
"""
Handle completion of an asynchronous log file read.
This function saves the output from that read for look()/look_for_all()
to process and records the current position. Future reads will pick
back up from that spot.
Arguments:
pid -- The ID of the process that did the read
returncode -- The return code of the process that did the read
out -- stdout from the file read
err -- stderr from the file read
"""
# It's not clear to me whether this function ever gets called as
# delegate somewhere, which is what would pass returncode and err
# as parameters. Just disable the warning for now.
# pylint: disable=unused-argument
# TODO: Probably need a lock for updating self._line_cache
self._logger.debug("%s: Got %d lines from %d (total %d)" % (self.name, len(out), pid, len(self._line_cache)))
if out:
with self._cache_lock:
self._line_cache.extend(out)
def __get_lines(self):
"""Iterate over all watched log files and collect new lines from each."""
if not self._file_list:
raise ValueError("No sources to read from")
pending = []
for f in self._file_list:
t = f.harvest_async(self)
if t:
pending.append(t)
for t in pending:
t.join(60.0)
if t.is_alive():
self._logger.log("%s: Aborting after 20s waiting for %r logging commands" % (self.name, t))
return
def end(self):
"""
Mark that a log is done being watched.
This function also resets internal data structures to the beginning
of the file. Subsequent watches will therefore start from the
beginning again.
"""
for f in self._file_list:
f.end()
def look(self, timeout=None):
"""
Examine the log looking for the regexes in this object.
It starts looking from the place marked by set_watch(), continuing
through the file in the fashion of `tail -f`. It properly recovers
from log file truncation but not from removing and recreating the log.
Arguments:
timeout -- Number of seconds to watch the log file; defaults to
seconds argument passed when this object was created
Returns the first line which matches any regex
"""
if not timeout:
timeout = self._timeout
lines = 0
begin = time.time()
end = begin + timeout + 1
if not self.regexes:
self._debug("Nothing to look for")
return None
if timeout == 0:
for f in self._file_list:
f.set_end()
while True:
if self._line_cache:
lines += 1
with self._cache_lock:
line = self._line_cache[0]
self._line_cache.remove(line)
which = -1
if re.search("CTS:", line):
continue
for regex in self.regexes:
which += 1
matchobj = re.search(regex, line)
if matchobj:
self.whichmatch = which
self._debug("Matched: %s" % line)
return line
elif timeout > 0 and end < time.time():
timeout = 0
for f in self._file_list:
f.set_end()
else:
self.__get_lines()
if not self._line_cache and end < time.time():
self._debug("Single search terminated: start=%d, end=%d, now=%d, lines=%d" % (begin, end, time.time(), lines))
return None
self._debug("Waiting: start=%d, end=%d, now=%d, lines=%d" % (begin, end, time.time(), len(self._line_cache)))
time.sleep(1)
- self._debug("How did we get here")
- return None
-
def look_for_all(self, allow_multiple_matches=False, silent=False):
"""
Like look(), but looks for matches for multiple regexes.
This function returns when the timeout is reached or all regexes were
matched. As a side effect, self.unmatched will contain regexes that
were not matched. This can be inspected by the caller.
Arguments:
allow_multiple_matches -- If True, allow each regex to match more than
once. If False (the default), once a regex
matches a line, it will no longer be searched
for.
silent -- If False, log extra information
Returns the matching lines if all regexes are matched, or None.
"""
save_regexes = self.regexes
result = []
if not silent:
self._debug("starting search: timeout=%d" % self._timeout)
while self.regexes:
one_result = self.look(self._timeout)
if not one_result:
self.unmatched = self.regexes
self.regexes = save_regexes
self.end()
return None
result.append(one_result)
if not allow_multiple_matches:
del self.regexes[self.whichmatch]
else:
# Allow multiple regexes to match a single line
tmp_regexes = self.regexes
self.regexes = []
for regex in tmp_regexes:
matchobj = re.search(regex, one_result)
if not matchobj:
self.regexes.append(regex)
self.unmatched = None
self.regexes = save_regexes
return result

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