zabbix-deploy/collector/history_tick.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Write the periodic history row from the last complete snapshot.

This runs every minute from cron, independently of the heavier full collection.
The SQL guard in l2_snapshot.write_history() enforces the configured interval,
so it only inserts when a new interval is due.  Keeping this out of the
refresh_alarms.sh full-lock gate is what guarantees a five-minute history even
while a full collection is running.
"""
import json
import os
import sys
import time

HERE = os.path.dirname(os.path.abspath(__file__))
sys.path.insert(0, HERE)

import l2_snapshot  # noqa: E402


def main():
    try:
        with open(l2_snapshot.OUT, encoding='utf-8') as f:
            snap = json.load(f)
        if not isinstance(snap, dict):
            return
        generated = int(snap.get('generated') or 0)
        # Do not snapshot a stale file if the full collector has stopped.
        if generated and time.time() - generated > 3600:
            return
        l2_snapshot.write_history(snap, int(time.time()))
    except Exception as e:
        print('history tick error:', e)


if __name__ == '__main__':
    main()