Service Watchdog

Lightweight service and endpoint monitoring for self-hosted infrastructure. Checks HTTP endpoints, TCP ports, SSL certificate expiry, and DNS resolution — then reports status in a clean, chat-friendly format.

What It Does

• HTTP Health Checks — GET/POST with expected status codes, response time tracking, content matching
• TCP Port Checks — Verify services are listening (databases, mail servers, game servers, etc.)
• SSL Certificate Monitoring — Days until expiry, issuer info, auto-warn thresholds
• DNS Resolution — Verify domains resolve correctly, detect DNS hijacking
• Smart Summaries — One-glance status for all your services, with trend data
• Alert Logic — Configurable thresholds, cooldowns, and severity levels to prevent alert fatigue

Quick Start

1. Create a watchlist

Create watchdog.json in your workspace root:

{
  "services": [
    {
      "name": "Home Assistant",
      "type": "http",
      "url": "http://192.168.1.100:8123",
      "expect_status": 200,
      "timeout_ms": 5000
    },
    {
      "name": "Proxmox",
      "type": "https",
      "url": "https://proxmox.local:8006",
      "expect_status": 200,
      "ssl_warn_days": 14,
      "timeout_ms": 5000
    },
    {
      "name": "PostgreSQL",
      "type": "tcp",
      "host": "db.local",
      "port": 5432,
      "timeout_ms": 3000
    },
    {
      "name": "My Domain",
      "type": "dns",
      "domain": "example.com",
      "expect_ip": "93.184.216.34"
    }
  ],
  "defaults": {
    "timeout_ms": 5000,
    "ssl_warn_days": 14,
    "alert_cooldown_min": 30,
    "history_retention_days": 30
  }
}

2. Run a check

bash skills/service-watchdog/watchdog.sh

Output example:

🟢 Home Assistant       — 200 OK (142ms)
🟢 Proxmox              — 200 OK (89ms) | SSL: 47 days
🟢 PostgreSQL           — port 5432 open (12ms)
🟢 My Domain            — resolves to 93.184.216.34 ✓
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
4/4 healthy | avg response: 81ms | checked: 2026-02-24 16:30 UTC

3. Detailed report

bash skills/service-watchdog/watchdog.sh --report

Shows trend data: uptime percentage, P95 response times, incident history.

4. JSON output (for cron integration)

bash skills/service-watchdog/watchdog.sh --json

5. Check SSL only

bash skills/service-watchdog/watchdog.sh --ssl-only

6. Alert summary (for messaging)

bash skills/service-watchdog/watchdog.sh --alerts-only

Only outputs services that need attention (down, slow, SSL expiring).

Cron Integration

Add to your OpenClaw cron for continuous monitoring:

Every 5 minutes (lightweight check):

Run `bash skills/service-watchdog/watchdog.sh --json` and report only if any service is unhealthy.

Daily SSL report:

Run `bash skills/service-watchdog/watchdog.sh --ssl-only` and report expiring certificates.

Configuration Reference

Service types

Type	Required Fields	Optional Fields
http / https	url	expect_status, expect_body, method, headers, timeout_ms, ssl_warn_days
tcp	host, port	timeout_ms
dns	domain	expect_ip, nameserver

Global defaults

Field	Default	Description
timeout_ms	5000	Request timeout
ssl_warn_days	14	SSL expiry warning threshold
alert_cooldown_min	30	Min minutes between repeated alerts
history_retention_days	30	How long to keep check history
history_file	watchdog-history.csv	Path for check history data

How the Agent Should Use This

When the user asks about service status, infrastructure health, or "are my services up?":

1. Run bash skills/service-watchdog/watchdog.sh for a quick overview
2. Run with --report for detailed trends and history
3. Run with --alerts-only for just the problems
4. Run with --ssl-only to check certificate status
5. Run with --json when you need structured data for further analysis

For proactive monitoring, run checks in cron jobs and only alert the user when something is wrong.

Requirements

• curl (for HTTP/HTTPS checks)
• openssl (for SSL certificate checks)
• nc or ncat (for TCP port checks) — falls back to bash /dev/tcp if unavailable
• dig or nslookup (for DNS checks) — falls back to host command
• jq (for JSON config parsing)

All standard on most Linux distributions. No external APIs or accounts needed.