# DevOps Subagent Guide

This guide covers DevOps-related subagents for deployment, infrastructure, and operations:

- **devops**: Containers, services, CI/CD pipelines, deployments
- **infra-architect**: Resource optimization, capacity planning
- **bg-worker**: Background jobs, PM2 workers, BullMQ queues

---

## CRITICAL: Server Access Model

**Claude Code has READ-ONLY access to production/test servers.**

The `claude-win10` user cannot execute write operations (PM2 restart, systemctl, file modifications) directly on servers. The devops subagent must **provide commands for the user to execute**, not attempt to run them via SSH.

### Command Delegation Workflow

When troubleshooting or making changes to production/test servers:

| Phase    | Actor  | Action                                                      |
| -------- | ------ | ----------------------------------------------------------- |
| Diagnose | Claude | Provide read-only diagnostic commands                       |
| Report   | User   | Execute commands, share output with Claude                  |
| Analyze  | Claude | Interpret results, identify root cause                      |
| Fix      | Claude | Provide 1-3 fix commands (never more, errors may cascade)   |
| Execute  | User   | Run fix commands, report results                            |
| Verify   | Claude | Provide verification commands to confirm success            |
| Document | Claude | Update relevant documentation with findings and resolutions |

### Example: PM2 Process Issue

Step 1 - Diagnostic Commands (Claude provides, user runs):

```bash
# Check PM2 process status
pm2 list

# View recent error logs
pm2 logs flyer-crawler-api --err --lines 50

# Check system resources
free -h
df -h /var/www
```

Step 2 - User reports output to Claude

Step 3 - Fix Commands (Claude provides 1-3 at a time):

```bash
# Restart the failing process
pm2 restart flyer-crawler-api
```

Step 4 - User executes and reports result

Step 5 - Verification Commands:

```bash
# Confirm process is running
pm2 list

# Test API health
curl -s https://flyer-crawler.projectium.com/api/health/ready | jq .
```

### What NOT to Do

```bash
# WRONG - Claude cannot execute this directly
ssh root@projectium.com "pm2 restart all"

# WRONG - Providing too many commands at once
pm2 stop all && rm -rf node_modules && npm install && pm2 start all

# WRONG - Assuming commands succeeded without user confirmation
```

---

## The devops Subagent

### When to Use

Use the **devops** subagent when you need to:

- Debug container issues in development
- Modify CI/CD pipelines
- Configure PM2 for production
- Update deployment workflows
- Troubleshoot service startup issues
- Configure NGINX or reverse proxy
- Set up SSL/TLS certificates

### What devops Knows

The devops subagent understands:

- Podman/Docker container management
- Dev container configuration (`.devcontainer/`)
- Compose files (`compose.dev.yml`)
- PM2 ecosystem configuration
- Gitea Actions CI/CD workflows
- NGINX configuration
- Systemd service management

### Development Environment

**Container Architecture:**

```
┌─────────────────────────────────────────────────────────────┐
│                    Development Environment                   │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────┐    ┌─────────────┐    ┌─────────────┐     │
│  │     app     │    │   postgres  │    │    redis    │     │
│  │  (Node.js)  │───►│  (PostGIS)  │    │   (Cache)   │     │
│  │             │───►│             │    │             │     │
│  └─────────────┘    └─────────────┘    └─────────────┘     │
│     :3000/:3001         :5432              :6379           │
└─────────────────────────────────────────────────────────────┘
```

**Container Services:**

| Service    | Image                   | Purpose                | Port       |
| ---------- | ----------------------- | ---------------------- | ---------- |
| `app`      | Custom (Dockerfile.dev) | Node.js application    | 3000, 3001 |
| `postgres` | postgis/postgis:15-3.4  | Database with PostGIS  | 5432       |
| `redis`    | redis:alpine            | Caching and job queues | 6379       |

### Example Requests

**Container debugging:**

```
"Use devops to debug why the dev container fails to start.
The postgres service shows as unhealthy and the app can't connect."
```

**CI/CD pipeline update:**

```
"Use devops to add a step to the deploy-to-test.yml workflow
that runs database migrations before restarting the app."
```

**PM2 configuration:**

```
"Use devops to update the PM2 ecosystem config to use cluster
mode with 4 instances instead of max for the API server."
```

### Container Commands Reference

```bash
# Start development environment
podman-compose -f compose.dev.yml up -d

# View container logs
podman-compose -f compose.dev.yml logs -f app

# Restart specific service
podman-compose -f compose.dev.yml restart app

# Rebuild container (after Dockerfile changes)
podman-compose -f compose.dev.yml build app

# Reset everything
podman-compose -f compose.dev.yml down -v
podman-compose -f compose.dev.yml up -d --build

# Enter container shell
podman exec -it flyer-crawler-dev bash

# Run tests in container (from Windows)
podman exec -it flyer-crawler-dev npm run test:unit
```

### Git Bash Path Conversion (Windows)

When running commands from Git Bash on Windows, paths may be incorrectly converted:

| Solution                   | Example                                                  |
| -------------------------- | -------------------------------------------------------- |
| `sh -c` with single quotes | `podman exec container sh -c '/usr/local/bin/script.sh'` |
| Double slashes             | `podman exec container //usr//local//bin//script.sh`     |
| MSYS_NO_PATHCONV=1         | `MSYS_NO_PATHCONV=1 podman exec ...`                     |

### PM2 Production Configuration

**ecosystem.config.cjs Structure:**

```javascript
module.exports = {
  apps: [
    {
      name: 'flyer-crawler-api',
      script: './node_modules/.bin/tsx',
      args: 'server.ts',
      instances: 'max', // Use all CPU cores
      exec_mode: 'cluster', // Enable cluster mode
      max_memory_restart: '500M',
      kill_timeout: 5000, // Graceful shutdown

      env_production: {
        NODE_ENV: 'production',
        cwd: '/var/www/flyer-crawler.projectium.com',
      },
    },
    {
      name: 'flyer-crawler-worker',
      script: './node_modules/.bin/tsx',
      args: 'src/services/worker.ts',
      instances: 1, // Single instance for workers
      max_memory_restart: '1G',
      kill_timeout: 10000, // Workers need more time
    },
  ],
};
```

**PM2 Commands:**

```bash
# Start/reload with environment
pm2 startOrReload ecosystem.config.cjs --env production --update-env

# Save process list
pm2 save

# View logs
pm2 logs flyer-crawler-api --lines 50

# Monitor processes
pm2 monit

# Describe process
pm2 describe flyer-crawler-api
```

### CI/CD Workflow Files

| File                                  | Purpose                     |
| ------------------------------------- | --------------------------- |
| `.gitea/workflows/deploy-to-prod.yml` | Production deployment       |
| `.gitea/workflows/deploy-to-test.yml` | Test environment deployment |

**Deployment Flow:**

1. Push to `main` branch
2. Gitea Actions triggered
3. SSH to production server
4. Pull latest code
5. Install dependencies
6. Run build
7. Run migrations
8. Restart PM2 processes

### Directory Structure (Production)

```
/var/www/
├── flyer-crawler.projectium.com/          # Production
│   ├── server.ts
│   ├── ecosystem.config.cjs
│   ├── package.json
│   ├── flyer-images/
│   │   ├── icons/
│   │   └── archive/
│   └── logs/
│       └── app.log
└── flyer-crawler-test.projectium.com/     # Test environment
    └── ... (same structure)
```

## The infra-architect Subagent

### When to Use

Use the **infra-architect** subagent when you need to:

- Analyze resource usage and optimize
- Plan for scaling
- Reduce infrastructure costs
- Configure memory limits
- Analyze disk usage
- Plan capacity for growth

### What infra-architect Knows

The infra-architect subagent understands:

- Node.js memory management
- PostgreSQL resource tuning
- Redis memory configuration
- Container resource limits
- PM2 process monitoring
- Disk and storage management

### Example Requests

**Memory optimization:**

```
"Use infra-architect to analyze memory usage of the worker
processes. They're frequently hitting the 1GB limit and restarting."
```

**Capacity planning:**

```
"Use infra-architect to estimate resource requirements for
handling 10x current traffic. Include database, Redis, and
application server recommendations."
```

**Cost optimization:**

```
"Use infra-architect to identify opportunities to reduce
infrastructure costs without impacting performance."
```

### Resource Limits Reference

| Process          | Memory Limit | Notes                 |
| ---------------- | ------------ | --------------------- |
| API Server       | 500MB        | Per cluster instance  |
| Worker           | 1GB          | Single instance       |
| Analytics Worker | 1GB          | Single instance       |
| PostgreSQL       | System RAM   | Tune `shared_buffers` |
| Redis            | 256MB        | `maxmemory` setting   |

## The bg-worker Subagent

### When to Use

Use the **bg-worker** subagent when you need to:

- Debug BullMQ queue issues
- Add new background job types
- Configure job retry logic
- Analyze job processing failures
- Optimize worker performance
- Handle job timeouts

### What bg-worker Knows

The bg-worker subagent understands:

- BullMQ queue patterns
- PM2 worker configuration
- Job retry and backoff strategies
- Queue monitoring and debugging
- Redis connection for queues
- Worker health checks (ADR-053)

### Queue Architecture

```
┌─────────────────┐    ┌─────────────────┐    ┌─────────────────┐
│   API Server    │───►│  Redis (BullMQ) │◄───│     Worker      │
│                 │    │                 │    │                 │
│  queue.add()    │    │ flyerQueue      │    │ process jobs    │
│                 │    │ cleanupQueue    │    │                 │
└─────────────────┘    │ analyticsQueue  │    └─────────────────┘
                       └─────────────────┘
```

### Example Requests

**Debugging stuck jobs:**

```
"Use bg-worker to debug why jobs are stuck in the flyer processing
queue. Check for failed jobs, worker status, and Redis connectivity."
```

**Adding retry logic:**

```
"Use bg-worker to add exponential backoff retry logic to the
AI extraction job. It should retry up to 3 times with increasing
delays for rate limit errors."
```

**Queue monitoring:**

```
"Use bg-worker to add health check endpoints for monitoring
queue depth and worker status."
```

### Queue Configuration

```typescript
// src/services/queues.server.ts
export const flyerQueue = new Queue('flyer-processing', {
  connection: redisConnection,
  defaultJobOptions: {
    attempts: 3,
    backoff: {
      type: 'exponential',
      delay: 1000,
    },
    removeOnComplete: { count: 100 },
    removeOnFail: { count: 1000 },
  },
});
```

### Worker Configuration

```typescript
// src/services/workers.server.ts
export const flyerWorker = new Worker(
  'flyer-processing',
  async (job) => {
    // Process job
  },
  {
    connection: redisConnection,
    concurrency: 5,
    limiter: {
      max: 10,
      duration: 1000,
    },
  },
);
```

### Monitoring Queues

```bash
# Check queue status via Redis
redis-cli -a $REDIS_PASSWORD

> KEYS bull:*
> LLEN bull:flyer-processing:wait
> ZRANGE bull:flyer-processing:failed 0 -1
```

## Service Management Commands

> **Note**: These commands are for the **user to execute on the server**. Claude Code provides these commands but cannot run them directly due to read-only server access. See [Server Access Model](#critical-server-access-model) above.

### PM2 Commands

```bash
# Start/reload
pm2 startOrReload ecosystem.config.cjs --env production --update-env && pm2 save

# View status
pm2 list
pm2 status

# View logs
pm2 logs
pm2 logs flyer-crawler-api --lines 100

# Restart specific process
pm2 restart flyer-crawler-api
pm2 restart flyer-crawler-worker

# Stop all
pm2 stop all

# Delete all
pm2 delete all
```

### Systemd Services (Production)

| Service    | Command                |
| ---------- | ---------------------- | ---- | ------------------------- |
| PostgreSQL | `sudo systemctl {start | stop | status} postgresql`       |
| Redis      | `sudo systemctl {start | stop | status} redis-server`     |
| NGINX      | `sudo systemctl {start | stop | status} nginx`            |
| Bugsink    | `sudo systemctl {start | stop | status} gunicorn-bugsink` |
| Logstash   | `sudo systemctl {start | stop | status} logstash`         |

### Health Checks

```bash
# API health check
curl http://localhost:3001/api/health

# PM2 health
pm2 list

# PostgreSQL health
pg_isready -h localhost -p 5432

# Redis health
redis-cli -a $REDIS_PASSWORD ping
```

## Troubleshooting Guide

### Container Won't Start

1. Check container logs: `podman-compose logs app`
2. Verify services are healthy: `podman-compose ps`
3. Check environment variables in `compose.dev.yml`
4. Try rebuilding: `podman-compose build --no-cache app`

### Tests Fail in Container but Pass Locally

Tests must run in the Linux container environment:

```bash
# Wrong (Windows)
npm test

# Correct (in container)
podman exec -it flyer-crawler-dev npm test
```

### PM2 Process Keeps Restarting

1. Check logs: `pm2 logs <process-name>`
2. Check memory usage: `pm2 monit`
3. Verify environment variables: `pm2 env <process-id>`
4. Check for unhandled errors in application code

### Database Connection Refused

1. Verify PostgreSQL is running
2. Check connection string in environment
3. Verify database user has permissions
4. Check `pg_hba.conf` for allowed connections

### Redis Connection Issues

1. Verify Redis is running: `redis-cli ping`
2. Check password in environment variables
3. Verify Redis is listening on expected port
4. Check `maxmemory` setting if queue operations fail

## Related Documentation

- [OVERVIEW.md](./OVERVIEW.md) - Subagent system overview
- [../BARE-METAL-SETUP.md](../BARE-METAL-SETUP.md) - Production setup guide
- [../adr/0014-containerization-and-deployment-strategy.md](../adr/0014-containerization-and-deployment-strategy.md) - Containerization ADR
- [../adr/0006-background-job-processing-and-task-queues.md](../adr/0006-background-job-processing-and-task-queues.md) - Background jobs ADR
- [../adr/0017-ci-cd-and-branching-strategy.md](../adr/0017-ci-cd-and-branching-strategy.md) - CI/CD strategy
- [../adr/0053-worker-health-checks.md](../adr/0053-worker-health-checks.md) - Worker health checks