77 lines
1.9 KiB
Python

import logging
import sys
import time
from django.core.management.base import BaseCommand
from django.db.models import Q
from django.utils import timezone
from hc.api.models import Check
logger = logging.getLogger(__name__)
def _stdout(message):
sys.stdout.write(message)
sys.stdout.flush()
def handle_one():
""" Send an alert for a single check.
Return True if an appropriate check was selected and processed.
Return False if no checks need to be processed.
"""
query = Check.objects.filter(user__isnull=False)
now = timezone.now()
going_down = Q(alert_after__lt=now, status="up")
going_up = Q(alert_after__gt=now, status="down")
query = query.filter(going_down | going_up)
try:
check = query[0]
except IndexError:
return False
check.status = check.get_status()
tmpl = "\nSending alert, status=%s, code=%s\n"
_stdout(tmpl % (check.status, check.code))
try:
check.send_alert()
except:
# Catch EVERYTHING. If we crash here, what can happen is:
# - the sendalerts command will crash
# - supervisor will respawn sendalerts command
# - sendalerts will try same thing again, resulting in infinite loop
# So instead we catch and log all exceptions, and mark
# the checks as paused so they are not retried.
logger.error("Could not alert %s" % check.code, exc_info=True)
check.status = "paused"
finally:
check.save()
return True
class Command(BaseCommand):
help = 'Sends UP/DOWN email alerts'
def handle(self, *args, **options):
ticks = 0
while True:
success = True
while success:
success = handle_one()
ticks = 0 if success else ticks + 1
time.sleep(1)
_stdout(".")
if ticks % 60 == 0:
_stdout("\n")