cron-doctor

name	cron-doctor
version	1.1.0
author	Polycat
tags	["cron","monitoring","diagnosis"]
license	MIT
platform	universal
description	Diagnose and triage cron job failures. Checks job states, identifies error patterns, prioritizes by criticality, generates health reports. Triggers on: cron failures, job health check, scheduled task errors, cron diagnosis, job not running, backup failed.

Compatible with Claude Code, Codex CLI, Cursor, Windsurf, and any SKILL.md-compatible agent.

Cron Doctor

Diagnose and triage cron job failures.

Usage

When asked to check cron health or diagnose failures:

1. List All Jobs

# List user's crontab
crontab -l

# List system crontabs
sudo cat /etc/crontab
ls -la /etc/cron.d/

2. Check Recent Execution

# Check cron logs (location varies by system)
# Debian/Ubuntu:
grep CRON /var/log/syslog | tail -50

# RHEL/CentOS:
tail -50 /var/log/cron

# macOS:
log show --predicate 'process == "cron"' --last 1h

# Check for specific job output
grep "your_job_name" /var/log/syslog | tail -20

3. Identify Problems

Error patterns to watch:

• "command not found" — Missing executable or PATH issue
• "Permission denied" — File/directory permissions wrong
• "No such file or directory" — Script path incorrect
• "timeout" — Job took too long
• "ECONNREFUSED" — Network/service down
• "rate limit" — API throttling
• Missing output — Job may not be running at all

4. Triage Priority

Priority	Criteria
🔴 Critical	Trading, backup, security jobs
🟠 High	User-facing deliveries
🟡 Medium	Monitoring, research jobs
🟢 Low	Nice-to-have, non-essential

5. Generate Report

Write to ~/reports/cron-health-YYYY-MM-DD.md:

# Cron Health Report - [DATE]

## Summary
- ✅ Healthy: X jobs
- ⚠️ Warning: X jobs  
- ❌ Failed: X jobs

## Failed Jobs

### [Job Name]
- **Error:** [message]
- **Last Success:** [date]
- **Priority:** [level]
- **Fix:** [suggested action]

## Recommendations
1. [Action item]
2. [Action item]

6. Common Fixes

Error	Fix
Command not found	Use full path to executable, or set PATH in crontab
Permission denied	Check file permissions, run chmod +x script.sh
No output	Add >> /tmp/job.log 2>&1 to capture output
Wrong timezone	Set TZ= in crontab or use system timezone
Rate limit	Reduce frequency or add backoff

7. Debugging Tips

# Test cron environment (cron has minimal PATH)
env -i /bin/sh -c 'echo $PATH'

# Verify script runs manually
/path/to/your/script.sh

# Check if cron daemon is running
systemctl status cron   # Linux
launchctl list | grep cron  # macOS

Escalation

If 3+ critical jobs failed, alert the user immediately.

Verification Gates

Before claiming diagnosis complete:

• All failed jobs listed — none skipped or ignored
• Priority assigned — based on impact, not just recency
• Fix suggested — actionable next step for each failure
• Report written — to ~/reports/cron-health-YYYY-MM-DD.md
• Critical failures escalated — 3+ critical = alert user