System Health Monitor

Perform a comprehensive health check of the multi-version Moodle development environment.

Check in this order:

1. Container Status

   • Run docker ps to verify all 3 containers are running
   • Check uptime and restart counts
   • Show container names, ports, and status

2. Service Status (inside moodle-dev container)

   • Nginx status: docker exec moodle-dev sudo systemctl status nginx
   • PHP-FPM pools: docker exec moodle-dev sudo systemctl status php8.1-fpm php8.2-fpm php8.3-fpm
   • Verify all services are active and running

3. PHP-FPM Sockets

   • List sockets: docker exec moodle-dev ls -la /run/php/
   • Verify all 4 sockets exist:
     • php8.1-fpm-41.sock
     • php8.1-fpm-dh-prod.sock
     • php8.2-fpm-45.sock
     • php8.3-fpm-51.sock

4. Database Connectivity

   • Test connection: docker exec moodle-dev mysql -h db -u moodleuser -pm@0dl3ing -e "SHOW DATABASES;"
   • Verify all 4 Moodle databases exist
   • Check database server uptime

5. Web Service Availability

   • Test each Moodle instance with curl (from inside container):
     • Port 8041 (Moodle 4.1)
     • Port 8043 (DH-Prod)
     • Port 8045 (Moodle 4.5)
     • Port 8051 (Moodle 5.1)
   • Expect HTTP 200 or 303 responses

6. System Resources

   • Disk usage: df -h (focus on /opt and /workspace)
   • Memory: free -h
   • Container resource usage: docker stats --no-stream

7. Recent Errors

   • Check last 10 lines of Nginx error logs for each instance
   • Check last 10 lines of PHP-FPM error logs
   • Highlight any critical errors

Output Format

Present results in a clear table format:

SERVICE HEALTH CHECK
====================

Containers: ✓ 3/3 running
Services:   ✓ nginx, php8.1-fpm, php8.2-fpm, php8.3-fpm
Sockets:    ✓ 4/4 present
Database:   ✓ Connected, 4 databases
Web:        ✓ 4/4 instances responding

Disk:       45% used (/opt)
Memory:     12.3 GB / 16 GB used

Recent Errors: None

If any checks fail, provide specific details and suggested remediation steps.