# crontab
0 3 * * * /path/to/backup.sh
0 6 * * * /path/to/report.sh
0 */2 * * * /path/to/cleanup.sh
# crontab
0 3 * * * /path/to/backup.sh
0 6 * * * /path/to/report.sh
0 */2 * * * /path/to/cleanup.sh
# crontab
0 3 * * * /path/to/backup.sh
0 6 * * * /path/to/report.sh
0 */2 * * * /path/to/cleanup.sh
import subprocess
import json
from datetime import datetime
from pathlib import Path
import urllib.request DB = Path.home() / '.cron-monitor.json' def load_db(): return json.loads(DB.read_text()) if DB.exists() else {'jobs': {}} def save_db(db): DB.write_text(json.dumps(db, indent=2, default=str)) def alert(message, bot_token, chat_id): url = f'https://api.telegram.org/bot{bot_token}/sendMessage' data = json.dumps({'chat_id': chat_id, 'text': message}).encode() req = urllib.request.Request(url, data=data, headers={'Content-Type': 'application/json'}) urllib.request.urlopen(req, timeout=10) def run_job(name, command, bot_token=None, chat_id=None): db = load_db() -weight: 500;">start = datetime.now() result = subprocess.run(command, capture_output=True, text=True) db['jobs'][name] = { 'last_run': -weight: 500;">start.isoformat(), 'duration': (datetime.now() - -weight: 500;">start).total_seconds(), 'exit_code': result.returncode, '-weight: 500;">status': 'success' if result.returncode == 0 else 'failed' } save_db(db) if result.returncode != 0 and bot_token: alert( f"🔴 CRON FAILED: {name}\n" f"Exit code: {result.returncode}\n" f"Error: {result.stderr[:200]}", bot_token, chat_id ) # Usage
run_job("daily-backup", ["bash", "/path/to/backup.sh"], bot_token="YOUR_BOT_TOKEN", chat_id="YOUR_CHAT_ID")
import subprocess
import json
from datetime import datetime
from pathlib import Path
import urllib.request DB = Path.home() / '.cron-monitor.json' def load_db(): return json.loads(DB.read_text()) if DB.exists() else {'jobs': {}} def save_db(db): DB.write_text(json.dumps(db, indent=2, default=str)) def alert(message, bot_token, chat_id): url = f'https://api.telegram.org/bot{bot_token}/sendMessage' data = json.dumps({'chat_id': chat_id, 'text': message}).encode() req = urllib.request.Request(url, data=data, headers={'Content-Type': 'application/json'}) urllib.request.urlopen(req, timeout=10) def run_job(name, command, bot_token=None, chat_id=None): db = load_db() -weight: 500;">start = datetime.now() result = subprocess.run(command, capture_output=True, text=True) db['jobs'][name] = { 'last_run': -weight: 500;">start.isoformat(), 'duration': (datetime.now() - -weight: 500;">start).total_seconds(), 'exit_code': result.returncode, '-weight: 500;">status': 'success' if result.returncode == 0 else 'failed' } save_db(db) if result.returncode != 0 and bot_token: alert( f"🔴 CRON FAILED: {name}\n" f"Exit code: {result.returncode}\n" f"Error: {result.stderr[:200]}", bot_token, chat_id ) # Usage
run_job("daily-backup", ["bash", "/path/to/backup.sh"], bot_token="YOUR_BOT_TOKEN", chat_id="YOUR_CHAT_ID")
import subprocess
import json
from datetime import datetime
from pathlib import Path
import urllib.request DB = Path.home() / '.cron-monitor.json' def load_db(): return json.loads(DB.read_text()) if DB.exists() else {'jobs': {}} def save_db(db): DB.write_text(json.dumps(db, indent=2, default=str)) def alert(message, bot_token, chat_id): url = f'https://api.telegram.org/bot{bot_token}/sendMessage' data = json.dumps({'chat_id': chat_id, 'text': message}).encode() req = urllib.request.Request(url, data=data, headers={'Content-Type': 'application/json'}) urllib.request.urlopen(req, timeout=10) def run_job(name, command, bot_token=None, chat_id=None): db = load_db() -weight: 500;">start = datetime.now() result = subprocess.run(command, capture_output=True, text=True) db['jobs'][name] = { 'last_run': -weight: 500;">start.isoformat(), 'duration': (datetime.now() - -weight: 500;">start).total_seconds(), 'exit_code': result.returncode, '-weight: 500;">status': 'success' if result.returncode == 0 else 'failed' } save_db(db) if result.returncode != 0 and bot_token: alert( f"🔴 CRON FAILED: {name}\n" f"Exit code: {result.returncode}\n" f"Error: {result.stderr[:200]}", bot_token, chat_id ) # Usage
run_job("daily-backup", ["bash", "/path/to/backup.sh"], bot_token="YOUR_BOT_TOKEN", chat_id="YOUR_CHAT_ID")
# Before (silent failures)
0 3 * * * /path/to/backup.sh # After (monitored)
0 3 * * * python3 /path/to/monitor.py --name "daily-backup" -- bash /path/to/backup.sh
# Before (silent failures)
0 3 * * * /path/to/backup.sh # After (monitored)
0 3 * * * python3 /path/to/monitor.py --name "daily-backup" -- bash /path/to/backup.sh
# Before (silent failures)
0 3 * * * /path/to/backup.sh # After (monitored)
0 3 * * * python3 /path/to/monitor.py --name "daily-backup" -- bash /path/to/backup.sh
=== Cron Job Monitor === Job: daily-backup Last run: 2026-03-25 03:00:01 Status: ✅ Success (exit code 0) Duration: 4m 23s Job: db-cleanup Last run: 2026-03-25 02:00:00 Status: 🔴 Failed (exit code 1) Error: "connection refused" Alert sent: Telegram ✅
=== Cron Job Monitor === Job: daily-backup Last run: 2026-03-25 03:00:01 Status: ✅ Success (exit code 0) Duration: 4m 23s Job: db-cleanup Last run: 2026-03-25 02:00:00 Status: 🔴 Failed (exit code 1) Error: "connection refused" Alert sent: Telegram ✅
=== Cron Job Monitor === Job: daily-backup Last run: 2026-03-25 03:00:01 Status: ✅ Success (exit code 0) Duration: 4m 23s Job: db-cleanup Last run: 2026-03-25 02:00:00 Status: 🔴 Failed (exit code 1) Error: "connection refused" Alert sent: Telegram ✅
0 3 * * * /path/to/backup.sh >> /var/log/backup.log 2>&1
0 3 * * * /path/to/backup.sh >> /var/log/backup.log 2>&1
0 3 * * * /path/to/backup.sh >> /var/log/backup.log 2>&1
0 3 * * * flock -n /tmp/backup.lock /path/to/backup.sh
0 3 * * * flock -n /tmp/backup.lock /path/to/backup.sh
0 3 * * * flock -n /tmp/backup.lock /path/to/backup.sh
PATH=/usr/local/bin:/usr/bin:/bin
0 3 * * * /path/to/backup.sh
PATH=/usr/local/bin:/usr/bin:/bin
0 3 * * * /path/to/backup.sh
PATH=/usr/local/bin:/usr/bin:/bin
0 3 * * * /path/to/backup.sh - Logs -weight: 500;">start/end time and exit code
- Sends a Telegram/Slack alert on failure
- Detects missed runs - Healthchecks.io — great -weight: 500;">service, but it's external. I want self-hosted.
- Cronitor — $20/month. This is free.
- systemd timers — powerful but complex to set up.
- Dead Man's Snitch — SaaS, costs money.
