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community.general/plugins/modules/monitoring/monit.py
Simon Kelly 8de1c0c205
monit: fix module detection of monitored process state (#1107)
* refactor and test

* require version >= 5.21.0

Prior to this version the status output was different

* python version compatability

* use exception classes from utils

* modify monit to use 'status' output instead of 'summary' output

The summary output is a fixed width table which truncates the
contents and prevents us from parsing the actual status of the
program.

* add integration tests + fixes

* remove unused handlers in monit integration test

* fix lint

* add '__metaclass__ = type' to integration python files

* raise AttributeError

* simplify status

* lint: add type to parameter docs

* remove lint ignore

* move monit process config into main file

* specify path to monit PID file

* set config location based on os_family

* create required directories

* update aliases to set group and skips

* add changelog

* add author

* add types to docs

* add EPEL repo

* custom vars for centos-6

* uninstall EPEL

* support older versions

* wait for status to change before exiting

* use 'validate' to force status updates

* handle 'execution failed'

* better status output for errors

* add more context to failure + standardize

* don't check rc for validate

* legacy string format support

* add integration test for 'reloaded' and 'present'

* don't wait after reload

* lint

* Revert "uninstall EPEL"

This reverts commit 4d548718d0.

* make 'present' more robust

* Apply suggestions from code review

Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>

* add license header

* drop daemon.py and use python-daemon instead

* skip python2.6 which is not supported by python-daemon

* refactor test tasks for reuse

* cleanup files after test

* lint

* start process before enabling monit

This shouldn't be necessary but I'm adding it in the hopes
it will make tests more robust.

* retry task

* attempt to rescue the task on failure

* fix indentation

* ignore check if rescue ran

* restart monit instead of reload

Co-authored-by: Andrew Klychkov <aaklychkov@mail.ru>
2020-10-23 12:26:23 +02:00

335 lines
11 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
# (c) 2013, Darryl Stoflet <stoflet@gmail.com>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
from __future__ import absolute_import, division, print_function
__metaclass__ = type
DOCUMENTATION = '''
---
module: monit
short_description: Manage the state of a program monitored via Monit
description:
- Manage the state of a program monitored via I(Monit).
options:
name:
description:
- The name of the I(monit) program/process to manage.
required: true
type: str
state:
description:
- The state of service.
required: true
choices: [ "present", "started", "stopped", "restarted", "monitored", "unmonitored", "reloaded" ]
type: str
timeout:
description:
- If there are pending actions for the service monitored by monit, then Ansible will check
for up to this many seconds to verify the requested action has been performed.
Ansible will sleep for five seconds between each check.
default: 300
type: int
author:
- Darryl Stoflet (@dstoflet)
- Simon Kelly (@snopoke)
'''
EXAMPLES = '''
- name: Manage the state of program httpd to be in started state
community.general.monit:
name: httpd
state: started
'''
import time
import re
from collections import namedtuple
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.six import python_2_unicode_compatible
STATE_COMMAND_MAP = {
'stopped': 'stop',
'started': 'start',
'monitored': 'monitor',
'unmonitored': 'unmonitor',
'restarted': 'restart'
}
@python_2_unicode_compatible
class StatusValue(namedtuple("Status", "value, is_pending")):
MISSING = 'missing'
OK = 'ok'
NOT_MONITORED = 'not_monitored'
INITIALIZING = 'initializing'
DOES_NOT_EXIST = 'does_not_exist'
EXECUTION_FAILED = 'execution_failed'
ALL_STATUS = [
MISSING, OK, NOT_MONITORED, INITIALIZING, DOES_NOT_EXIST, EXECUTION_FAILED
]
def __new__(cls, value, is_pending=False):
return super(StatusValue, cls).__new__(cls, value, is_pending)
def pending(self):
return StatusValue(self.value, True)
def __getattr__(self, item):
if item in ('is_%s' % status for status in self.ALL_STATUS):
return self.value == getattr(self, item[3:].upper())
raise AttributeError(item)
def __str__(self):
return "%s%s" % (self.value, " (pending)" if self.is_pending else "")
class Status(object):
MISSING = StatusValue(StatusValue.MISSING)
OK = StatusValue(StatusValue.OK)
RUNNING = StatusValue(StatusValue.OK)
NOT_MONITORED = StatusValue(StatusValue.NOT_MONITORED)
INITIALIZING = StatusValue(StatusValue.INITIALIZING)
DOES_NOT_EXIST = StatusValue(StatusValue.DOES_NOT_EXIST)
EXECUTION_FAILED = StatusValue(StatusValue.EXECUTION_FAILED)
class Monit(object):
def __init__(self, module, monit_bin_path, service_name, timeout):
self.module = module
self.monit_bin_path = monit_bin_path
self.process_name = service_name
self.timeout = timeout
self._monit_version = None
self._raw_version = None
self._status_change_retry_count = 6
def monit_version(self):
if self._monit_version is None:
self._raw_version, version = self._get_monit_version()
# Use only major and minor even if there are more these should be enough
self._monit_version = version[0], version[1]
return self._monit_version
def _get_monit_version(self):
rc, out, err = self.module.run_command('%s -V' % self.monit_bin_path, check_rc=True)
version_line = out.split('\n')[0]
raw_version = re.search(r"([0-9]+\.){1,2}([0-9]+)?", version_line).group()
return raw_version, tuple(map(int, raw_version.split('.')))
def exit_fail(self, msg, status=None, **kwargs):
kwargs.update({
'msg': msg,
'monit_version': self._raw_version,
'process_status': str(status) if status else None,
})
self.module.fail_json(**kwargs)
def exit_success(self, state):
self.module.exit_json(changed=True, name=self.process_name, state=state)
@property
def command_args(self):
return "-B" if self.monit_version() > (5, 18) else ""
def get_status(self, validate=False):
"""Return the status of the process in monit.
:@param validate: Force monit to re-check the status of the process
"""
monit_command = "validate" if validate else "status"
check_rc = False if validate else True # 'validate' always has rc = 1
command = ' '.join([self.monit_bin_path, monit_command, self.command_args, self.process_name])
rc, out, err = self.module.run_command(command, check_rc=check_rc)
return self._parse_status(out, err)
def _parse_status(self, output, err):
if "Process '%s'" % self.process_name not in output:
return Status.MISSING
status_val = re.findall(r"^\s*status\s*([\w\- ]+)", output, re.MULTILINE)
if not status_val:
self.exit_fail("Unable to find process status", stdout=output, stderr=err)
status_val = status_val[0].strip().upper()
if ' | ' in status_val:
status_val = status_val.split(' | ')[0]
if ' - ' not in status_val:
status_val = status_val.replace(' ', '_')
return getattr(Status, status_val)
else:
status_val, substatus = status_val.split(' - ')
action, state = substatus.split()
if action in ['START', 'INITIALIZING', 'RESTART', 'MONITOR']:
status = Status.OK
else:
status = Status.NOT_MONITORED
if state == 'pending':
status = status.pending()
return status
def is_process_present(self):
rc, out, err = self.module.run_command('%s summary %s' % (self.monit_bin_path, self.command_args), check_rc=True)
return bool(re.findall(r'\b%s\b' % self.process_name, out))
def is_process_running(self):
return self.get_status().is_ok
def run_command(self, command):
"""Runs a monit command, and returns the new status."""
return self.module.run_command('%s %s %s' % (self.monit_bin_path, command, self.process_name), check_rc=True)
def wait_for_status_change(self, current_status):
running_status = self.get_status()
if running_status.value != current_status.value or current_status.value == StatusValue.EXECUTION_FAILED:
return running_status
loop_count = 0
while running_status.value == current_status.value:
if loop_count >= self._status_change_retry_count:
self.exit_fail('waited too long for monit to change state', running_status)
loop_count += 1
time.sleep(0.5)
validate = loop_count % 2 == 0 # force recheck of status every second try
running_status = self.get_status(validate)
return running_status
def wait_for_monit_to_stop_pending(self, current_status=None):
"""Fails this run if there is no status or it's pending/initializing for timeout"""
timeout_time = time.time() + self.timeout
if not current_status:
current_status = self.get_status()
waiting_status = [
StatusValue.MISSING,
StatusValue.INITIALIZING,
StatusValue.DOES_NOT_EXIST,
]
while current_status.is_pending or (current_status.value in waiting_status):
if time.time() >= timeout_time:
self.exit_fail('waited too long for "pending", or "initiating" status to go away', current_status)
time.sleep(5)
current_status = self.get_status(validate=True)
return current_status
def reload(self):
rc, out, err = self.module.run_command('%s reload' % self.monit_bin_path)
if rc != 0:
self.exit_fail('monit reload failed', stdout=out, stderr=err)
self.exit_success(state='reloaded')
def present(self):
self.run_command('reload')
timeout_time = time.time() + self.timeout
while not self.is_process_present():
if time.time() >= timeout_time:
self.exit_fail('waited too long for process to become "present"')
time.sleep(5)
self.exit_success(state='present')
def change_state(self, state, expected_status, invert_expected=None):
current_status = self.get_status()
self.run_command(STATE_COMMAND_MAP[state])
status = self.wait_for_status_change(current_status)
status = self.wait_for_monit_to_stop_pending(status)
status_match = status.value == expected_status.value
if invert_expected:
status_match = not status_match
if status_match:
self.exit_success(state=state)
self.exit_fail('%s process not %s' % (self.process_name, state), status)
def stop(self):
self.change_state('stopped', Status.NOT_MONITORED)
def unmonitor(self):
self.change_state('unmonitored', Status.NOT_MONITORED)
def restart(self):
self.change_state('restarted', Status.OK)
def start(self):
self.change_state('started', Status.OK)
def monitor(self):
self.change_state('monitored', Status.NOT_MONITORED, invert_expected=True)
def main():
arg_spec = dict(
name=dict(required=True),
timeout=dict(default=300, type='int'),
state=dict(required=True, choices=['present', 'started', 'restarted', 'stopped', 'monitored', 'unmonitored', 'reloaded'])
)
module = AnsibleModule(argument_spec=arg_spec, supports_check_mode=True)
name = module.params['name']
state = module.params['state']
timeout = module.params['timeout']
monit = Monit(module, module.get_bin_path('monit', True), name, timeout)
def exit_if_check_mode():
if module.check_mode:
module.exit_json(changed=True)
if state == 'reloaded':
exit_if_check_mode()
monit.reload()
present = monit.is_process_present()
if not present and not state == 'present':
module.fail_json(msg='%s process not presently configured with monit' % name, name=name)
if state == 'present':
if present:
module.exit_json(changed=False, name=name, state=state)
exit_if_check_mode()
monit.present()
monit.wait_for_monit_to_stop_pending()
running = monit.is_process_running()
if running and state in ['started', 'monitored']:
module.exit_json(changed=False, name=name, state=state)
if running and state == 'stopped':
exit_if_check_mode()
monit.stop()
if running and state == 'unmonitored':
exit_if_check_mode()
monit.unmonitor()
elif state == 'restarted':
exit_if_check_mode()
monit.restart()
elif not running and state == 'started':
exit_if_check_mode()
monit.start()
elif not running and state == 'monitored':
exit_if_check_mode()
monit.monitor()
module.exit_json(changed=False, name=name, state=state)
if __name__ == '__main__':
main()