# Gravl Deployment Guide

This guide covers how to deploy Gravl's backend and frontend services using automated scripts, verify deployment status, and handle troubleshooting and recovery scenarios.

---

## Overview

Gravl uses Docker and Docker Compose for containerization. Two automated scripts manage the deployment lifecycle:

- **`scripts/deploy.sh`**: Pulls latest code, builds fresh images (with `--no-cache` to prevent stale assets), and starts containers with health checks
- **`scripts/build-check.sh`**: Verifies that running containers match the current git HEAD (detects stale deployments)

---

## Prerequisites

Before deploying, ensure you have:

1. **Docker & Docker Compose** installed and running
   ```bash
   docker --version
   docker compose version
   ```

2. **Git** configured with push/pull access to the repository
   ```bash
   git remote -v
   ```

3. **Network access** to required ports:
   - Backend: `localhost:3001` (health check at `http://localhost:3001/api/health`)
   - Frontend: `localhost:3000` (or configured in `docker-compose.yml`)

4. **Sufficient disk space** for Docker images and volumes
   ```bash
   docker system df
   ```

5. **No conflicting services** using ports 3000-3001
   ```bash
   lsof -i :3000 -i :3001  # (macOS/Linux only)
   ```

---

## How to Run `deploy.sh`

### Basic Usage

```bash
cd /workspace/gravl
scripts/deploy.sh
```

### What It Does

1. **Git Pull**: Fetches and merges latest code from remote
   - Exits if merge conflicts occur (manual resolution required)
   
2. **Captures Metadata**:
   - Current git commit hash
   - Build timestamp
   - These are stored as Docker image labels for later verification
   
3. **Builds Docker Images** (`--no-cache`):
   - Rebuilds all layers (no caching) to prevent stale assets
   - Applies git commit and build timestamp as labels
   
4. **Starts Containers**:
   - Uses `docker compose up -d --force-recreate` to ensure clean start
   - Both backend and frontend containers are started
   
5. **Health Check**:
   - Waits up to 60 seconds for backend to respond on `/api/health`
   - Retries every 5 seconds (12 attempts max)
   - Fails with exit code 1 if health check times out

### Exit Codes

| Code | Meaning | Next Steps |
|------|---------|-----------|
| 0 | Success | Deployment complete; containers healthy |
| 1 | Failure | See troubleshooting below |

### Logs

All deploy activity is logged to `logs/deploy.log`:

```bash
tail -50 logs/deploy.log           # Last 50 lines
grep ERROR logs/deploy.log        # Find errors
```

### Environment Variables

Optional env vars can be set before running `deploy.sh`:

| Variable | Default | Purpose |
|----------|---------|---------|
| `GIT_COMMIT` | auto-detected | Override git commit label (not recommended) |
| `BUILD_DATE` | auto-detected | Override build timestamp (not recommended) |

---

## How to Check Build Status (`build-check.sh`)

Run this command anytime to verify deployed containers match your local code:

```bash
scripts/build-check.sh
```

### Output Example

**Healthy deployment:**
```
Local HEAD: abc1234 (abc1234567890abcdef1234567890abcdef123456)

[gravl-backend] Built: abc1234 on 2026-03-03T18:21:00Z
[gravl-backend] OK: up to date
[gravl-frontend] Built: abc1234 on 2026-03-03T18:21:00Z
[gravl-frontend] OK: up to date
```

**Stale containers (code updated, not redeployed):**
```
Local HEAD: xyz5678 (xyz5678...)

[gravl-backend] Built: abc1234 on 2026-03-03T18:21:00Z
[gravl-backend] STALE: container is behind local code — run scripts/deploy.sh
[gravl-frontend] Built: abc1234 on 2026-03-03T18:21:00Z
[gravl-frontend] STALE: container is behind local code — run scripts/deploy.sh
```

**Missing labels (container built manually, not via deploy.sh):**
```
Local HEAD: abc1234

[gravl-backend] WARNING: no build label found — redeploy with scripts/deploy.sh to add tracking
[gravl-frontend] Not running
```

### Exit Codes

| Code | Meaning |
|------|---------|
| 0 | All checks completed (warnings don't fail; see output for status) |
| (no error exit) | Missing containers are noted but don't cause failure |

---

## Troubleshooting

### Health Check Failures

**Symptom:** `ERROR: Health check failed after 60s`

**Causes & Solutions:**

1. **Backend service didn't start**
   ```bash
   docker logs gravl-backend | tail -20
   # Look for: 
   # - Port conflicts (ERR_EADDRINUSE)
   # - Missing dependencies (module not found)
   # - Database connection errors
   ```

2. **Port 3001 is already in use**
   ```bash
   lsof -i :3001  # Find what's using it
   docker port gravl-backend  # Check exposed port
   kill -9 <PID>  # Kill conflicting process (if safe)
   scripts/deploy.sh  # Retry
   ```

3. **Network issue between host and container**
   ```bash
   docker inspect gravl-backend --format '{{.NetworkSettings.IPAddress}}'
   curl -sf http://<container-ip>:3001/api/health  # Test directly
   ```

4. **Backend code has syntax error**
   ```bash
   docker logs gravl-backend 2>&1 | grep -i "syntax\|error\|exception"
   # Check backend/src/index.js for obvious errors
   # Revert recent changes: git log --oneline -5 && git checkout <good-commit>
   ```

**Quick recovery:**

```bash
# 1. Stop everything
docker compose down

# 2. Check backend logs
docker compose up -d gravl-backend
sleep 5
docker logs gravl-backend | tail -50

# 3. If logs show errors, fix code and retry
git diff HEAD~1..HEAD backend/src/
# ... fix issues ...
scripts/deploy.sh
```

---

### Stale Containers

**Symptom:** `build-check.sh` shows `STALE: container is behind local code`

**Causes:**

- Code was updated (`git pull`) but `deploy.sh` hasn't been run
- Deployment failed partway through
- Manual restart without redeploy

**Solution:**

```bash
scripts/deploy.sh
scripts/build-check.sh  # Verify update
```

---

### Missing Build Labels

**Symptom:** `WARNING: no build label found — redeploy with scripts/deploy.sh`

**Causes:**

- Container was built with `docker compose build` directly (not via `deploy.sh`)
- Container predates the labeling system

**Solution:**

```bash
# Re-deploy to add labels
scripts/deploy.sh
```

---

### Container Won't Start (CrashLoopBackOff / Exited)

**Symptom:** `docker compose ps` shows container in "Exited" state

**Steps:**

1. **Check container logs**
   ```bash
   docker logs gravl-backend --tail 50
   docker logs gravl-frontend --tail 50
   ```

2. **Check docker-compose.yml for typos**
   ```bash
   docker compose config  # Validates syntax
   ```

3. **Inspect health check endpoint**
   ```bash
   curl -v http://localhost:3001/api/health
   # Should see HTTP 200, not 404 or 500
   ```

4. **If all else fails, clean rebuild**
   ```bash
   docker compose down
   docker rmi gravl-backend gravl-frontend
   docker system prune -f
   scripts/deploy.sh
   ```

---

### Database Connection Issues

**Symptom:** Backend logs show `Connection refused` or `ECONNREFUSED`

**Causes:**
- Database service not running
- Wrong host/port in `.env` or backend code
- Network issue between containers

**Solutions:**

1. **Check database service status** (if applicable)
   ```bash
   docker compose ps  # All services running?
   docker network ls  # Check gravl network exists
   ```

2. **Verify connection string in `.env`**
   ```bash
   cat .env | grep -i database
   # Should match docker-compose.yml service name (e.g., gravl-db:5432)
   ```

3. **Test connection from backend container**
   ```bash
   docker exec gravl-backend ping gravl-db
   docker exec gravl-backend curl http://gravl-db:5432  # If HTTP, adjust port
   ```

---

### Disk Space Issues

**Symptom:** `no space left on device` during build

**Solution:**

```bash
# Check disk usage
docker system df

# Clean up unused images/containers
docker system prune -a --volumes

# Then retry deploy
scripts/deploy.sh
```

---

## Recovery Procedures

### Manual Rollback to Previous Commit

Use this when the deployed code is broken and you need to quickly revert.

```bash
# 1. Find the last good commit
git log --oneline -10  # Review recent commits

# 2. Check out the known-good commit
git checkout <commit-hash>

# 3. Redeploy
scripts/deploy.sh

# 4. Verify
scripts/build-check.sh
curl -sf http://localhost:3001/api/health

# 5. Document the incident
echo "Rolled back to <commit-hash> due to <reason>" >> logs/rollback.log
```

### Emergency Container Cleanup

Use this when containers are hung, corrupted, or in an unknown state.

```bash
# 1. Stop all services
docker compose down

# 2. Remove images (forces fresh rebuild)
docker rmi gravl-backend gravl-frontend

# 3. Clear unused volumes (optional; use with caution!)
# docker volume prune

# 4. Rebuild from scratch
scripts/deploy.sh

# 5. Verify all containers running and healthy
docker compose ps
scripts/build-check.sh
curl -sf http://localhost:3001/api/health
```

**Safety Check:** If your data is in Docker volumes, `docker volume prune` will destroy them. Skip this step unless you're sure you don't need the data.

### Staged Rollback (Zero-Downtime)

If you're running a blue-green deployment setup:

```bash
# 1. Deploy to green environment
cd /path/to/green
git pull && docker compose build --no-cache && docker compose up -d

# 2. Test green (health check, smoke tests)
curl -sf http://green-backend:3001/api/health

# 3. Switch traffic to green (via load balancer or DNS)
# (Implementation depends on your infrastructure)

# 4. If green has issues, revert traffic to blue immediately
# (Blue kept serving; no downtime)

# 5. Debug green offline
docker logs gravl-backend
```

---

## Monitoring After Deployment

### Immediate Checks (after `deploy.sh` completes)

```bash
# Containers are running
docker compose ps

# Backend is healthy
curl -sf http://localhost:3001/api/health | jq .

# Containers match local code
scripts/build-check.sh

# Logs have no errors
docker logs gravl-backend 2>&1 | grep -i error | head -5
```

### Ongoing Checks (periodically)

```bash
# Run build-check regularly (cron every 30 min, or manual)
scripts/build-check.sh

# Monitor resource usage
docker stats gravl-backend gravl-frontend

# Audit logs for issues
docker logs gravl-backend --since 1h --until now | grep ERROR
```

### Example Monitoring Script

```bash
#!/bin/bash
# Save as scripts/health-monitor.sh
set -euo pipefail

HEALTHY=true

# Check containers running
docker compose ps | grep -q "Up" || HEALTHY=false

# Check health endpoint
curl -sf http://localhost:3001/api/health || HEALTHY=false

# Check for stale containers
scripts/build-check.sh | grep -q "STALE" && HEALTHY=false

if [ "$HEALTHY" = "true" ]; then
  echo "[$(date)] Gravl is healthy ✓"
else
  echo "[$(date)] Gravl has issues! See above." >&2
  exit 1
fi
```

---

## Best Practices

1. **Always run `build-check.sh` before deploying changes**
   - Ensures you know current state
   - Catches stale containers early

2. **Review changes before deploying**
   ```bash
   git log --oneline -5  # Recent commits
   git diff origin/main..HEAD  # What will be deployed
   ```

3. **Test in staging first**
   - Separate staging environment for pre-production testing
   - Deploy to staging, verify, then deploy to production

4. **Keep logs rotated**
   - `logs/deploy.log` can grow large
   - Use `logrotate` or manual cleanup: `tail -1000 logs/deploy.log > logs/deploy.log.1 && > logs/deploy.log`

5. **Automate regular checks**
   - Cron job to run `build-check.sh` every 30 minutes
   - Send alerts if "STALE" or "WARNING" found

6. **Document rollbacks**
   - Always log why you rolled back
   - Review patterns (e.g., "rolled back 3 times this week" = code review process failing)

---

## See Also

- **Testing**: [DEPLOYMENT_TEST_PLAN.md](./DEPLOYMENT_TEST_PLAN.md) — comprehensive test scenarios
- **Code style**: [CODING-CONVENTIONS.md](./CODING-CONVENTIONS.md)
- **Architecture**: Backend README or architecture docs (if available)

---

*Last updated: 2026-03-03 | Maintained by: Gravl Development Team*