This commit is contained in:
IamTheFij 2018-02-15 18:10:19 -08:00
parent e34fa38d51
commit 202ca73e96
2 changed files with 234 additions and 37 deletions

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@ -1,4 +1,8 @@
from argparse import ArgumentParser
from datetime import datetime
from os import environ
from subprocess import CalledProcessError
from subprocess import call
from subprocess import check_call
from time import sleep
@ -6,38 +10,218 @@ import yamlenv
# TODO: validate on start
def get_config(path):
def read_yaml(path):
"""Loads config from a YAML file with env interpolation"""
with open(path, 'r') as yaml:
contents = yaml.read()
return yamlenv.load(contents)
def check_monitor(monitor):
cmd = monitor.get('command', [])
if cmd:
check_call(cmd, shell=isinstance(cmd, str))
class InvalidAlertException(Exception):
pass
def alert_for_monitor(monitor, alerts):
for alert_name in monitor.get('alerts', []):
cmd = alerts.get(alert_name, {}).get('command', [])
if cmd:
check_call(cmd, shell=isinstance(cmd, str))
class InvalidMonitorException(Exception):
pass
def main():
# TODO: get config file off command line
config = get_config('config.yml')
alerts = config.get('alerts', {})
while True:
for monitor in config.get('monitors', []):
try:
check_monitor(monitor)
except CalledProcessError:
# Need some way to not alert EVERY time
alert_for_monitor(monitor, alerts)
sleep(config.get('interval', 1))
class MinitorAlert(Exception):
pass
class Monitor(object):
"""Primary configuration item for Minitor"""
def __init__(self, config):
"""Accepts a dictionary of configuration items to override defaults"""
settings = {
'alerts': [ 'log' ],
'check_interval': 30,
'alert_after': 3,
'alert_every': 4,
}
settings.update(config)
self.validate_settings(settings)
self.name = settings['name']
self.command = settings['command']
self.alerts = settings.get('alerts', [])
self.check_interval = settings.get('check_interval')
self.alert_after = settings.get('alert_after')
self.alert_every = settings.get('alert_every')
self.last_check = None
self.failure_count = 0
def validate_settings(self, settings):
"""Validates that settings for this Monitor are valid
Note: Cannot yet validate the Alerts exist from within this class.
That will be done by Minitor later
"""
name = settings.get('name')
if not name:
raise InvalidMonitorException('Invalid name for monitor')
if not settings.get('command'):
raise InvalidMonitorException(
'Invalid command for monitor {}'.format(name)
)
type_assertions = (
('check_interval', int),
('alert_after', int),
('alert_every', int),
)
for key, val_type in type_assertions:
val = settings.get(key)
if not isinstance(val, val_type):
raise InvalidMonitorException(
'Invalid type on {} {}. Expected {} and found {}'.format(
name, key, val_type.__name__, type(val).__name__
)
)
def should_check(self):
"""Determines if this Monitor should run it's check command"""
if not self.last_check:
return True
since_last_check = (datetime.now()-self.last_check).total_seconds()
return since_last_check >= self.check_interval
def check(self):
"""Returns None if skipped, False if failed, and True if successful
Will raise an exception if should alert
"""
if not self.should_check():
return None
result = call(self.command, shell=isinstance(self.command, str))
self.last_check = datetime.now()
if result == 0:
self.success()
return True
else:
self.failure()
return False
def success(self):
"""Handles success tasks"""
self.failure_count = 0
def failure(self):
"""Handles failure tasks and possibly raises MinitorAlert"""
self.failure_count += 1
min_failures = self.failure_count >= self.alert_after
failure_interval = (self.failure_count % self.alert_every) == 0
if min_failures and failure_interval:
raise MinitorAlert('{} check has failed {} times'.format(
self.name, self.failure_count
))
class Alert(object):
def __init__(self, name, config):
"""An alert must be named and have a config dict"""
self.name = name
self.command = config.get('command')
if not self.command:
raise InvalidAlertException('Invalid alert {}'.format(self.name))
def _formated_command(self, **kwargs):
"""Formats command array or string with kwargs from Monitor"""
if isinstance(self.command, str):
return self.command.format(**kwargs)
args = []
for arg in self.command:
args.append(arg.format(**kwargs))
return args
def alert(self, monitor):
"""Calls the alert command for the provided monitor"""
check_call(
self._formated_command(monitor_name=monitor.name),
shell=isinstance(self.command, str),
)
class Minitor(object):
monitors = None
alerts = None
state = None
check_interval = None
def setup(self, config_path):
"""Load all setup from YAML file at provided path"""
config = read_yaml(config_path)
self.check_interval = config.get('check_interval', 30)
self.monitors = [Monitor(mon) for mon in config.get('monitors', [])]
# Add default alert for logging
self.alerts = {
'log': Alert(
'log',
{'command': ['echo', '{monitor_name} has failed!']}
)
}
self.alerts.update({
alert_name: Alert(alert_name, alert)
for alert_name, alert in config.get('alerts', {}).items()
})
def validate_monitors(self):
"""Validates monitors are valid against other config values"""
for monitor in self.monitors:
# Validate that the interval is valid
if monitor.check_interval < self.check_interval:
raise InvalidMonitorException(
'Monitor {} check interval is lower global value {}'.format(
monitor.name, self.check_interval
)
)
# Validate that the the alerts for the monitor exist
for alert in monitor.alerts:
if alert not in self.alerts:
raise InvalidMonitorException(
'Monitor {} contains an unknown alert: {}'.format(
monitor.name, alert
)
)
def alert_for_monitor(self, monitor):
"""Issues all alerts for a provided monitor"""
for alert in monitor.alerts:
self.alerts[alert].alert(monitor)
def parse_args(self):
"""Parses command line arguments and returns them"""
parser = ArgumentParser(description='Minimal monitoring')
parser.add_argument(
'--config', '-c',
dest='config_path',
default='config.yml',
help='Path to the config YAML file to use'
)
return parser.parse_args()
def run(self):
"""Runs Minitor in a loop"""
args = self.parse_args()
self.setup(args.config_path)
self.validate_monitors()
while True:
for monitor in self.monitors:
try:
result = monitor.check()
if result is not None:
print('{}: {}'.format(
monitor.name,
'SUCCESS' if result else 'FAILURE'
))
except MinitorAlert as minitor_alert:
print(minitor_alert)
self.alert_for_monitor(monitor)
sleep(self.check_interval)
if __name__ == '__main__':
main()
Minitor().run()

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@ -1,21 +1,34 @@
interval: 5
check_interval: 30
monitors:
- name: View
command: [ 'curl', 'https://localhost:5000' ]
# environment:
# PATH: ${PATH}
alerts: [ email, sms ]
# other settings from other health check apps like interval and back off
- name: My Website
command: [ 'curl', 'https://minitor.mon' ]
alerts: [ log, email, sms ]
check_interval: 30
alert_after: 3
alert_every: 4
alerts:
email:
command: echo 'Send an email'
command: [ sendmail, "me@minitor.mon", "Failure: {monitor_name}", "This thing failed!" ]
mailgun:
command: >
curl -s -X POST
-F subject="Alert! {alert_name} failed"
-F from="Minitor <minitor@minitor.mon>"
-F to=me@minitor.mon
-F text="Our monitor failed"
https://api.mailgun.net/v3/minitor.mon/messages
-u "api:${TWILIO_API_KEY}"
sms:
command: echo 'Send an SMS'
command: >
curl -s -X POST -F "Body=Failure: {monitor_name} has failed"
-F "From=${AVAILABLE_NUMBER}" -F "To=${MY_PHONE}"
"https://api.twilio.com/2010-04-01/Accounts/${ACCOUNT_SID}/Messages"
-u "${ACCOUNT_SID}:${AUTH_TOKEN}"
federation:
- location: https://host1.com
client_key: keyfromhost1
server_key: keyhost1uses
alerts: [ sms ]
# federation:
# - location: https://host1.com
# client_key: keyfromhost1
# server_key: keyhost1uses
# alerts: [ sms ]