# PostgreSQL Production Stack - Production Database

## Overview

Production-ready PostgreSQL 16 database stack with automated backup system and performance optimization.

**Features**:
- PostgreSQL 16 Alpine (lightweight, secure)
- Automated daily backups with configurable retention
- Performance-optimized configuration (2GB memory allocation)
- Health checks and automatic recovery
- Persistent storage with named volumes
- Isolated `postgres-production-internal` network
- Resource limits for stability

## Services

- **postgres-production** - PostgreSQL 16 database server
- **postgres-production-backup** - Automated backup service with cron scheduling

## Prerequisites

1. **Docker and Docker Compose** installed
2. **Environment file** created (`.env`)

## Configuration

### 1. Create Environment File

```bash
cp .env.example .env
```

### 2. Generate Secure Password

```bash
openssl rand -base64 32
```

Update `.env`:
```env
POSTGRES_DB=michaelschiemer
POSTGRES_USER=postgres
POSTGRES_PASSWORD=<generated-password>
BACKUP_RETENTION_DAYS=7
BACKUP_SCHEDULE=0 2 * * *
```

## Deployment

### Initial Setup

```bash
# Create environment file
cp .env.example .env

# Generate and set password
openssl rand -base64 32
# Update POSTGRES_PASSWORD in .env

# Start services
docker compose up -d

# Check logs
docker compose logs -f

# Verify health
docker compose ps
```

### Verify Deployment

```bash
# Check PostgreSQL is running
docker exec postgres-production pg_isready -U postgres -d michaelschiemer

# Expected: postgres-production:5432 - accepting connections

# Check backup service
docker compose logs postgres-production-backup

# Expected: Initial backup completed successfully
```

## Integration with Production Application Stack

The Production Application Stack connects to this database via the `postgres-production-internal` network.

**Connection Configuration** in `deployment/stacks/production/.env`:
```env
DB_HOST=postgres-production
DB_PORT=5432
DB_DATABASE=michaelschiemer
DB_USERNAME=postgres
DB_PASSWORD=<same-as-postgres-production-password>
```

**Network Connection**: The Production Application Stack must be connected to the `postgres-production-internal` network.

## Usage

### Database Access

#### From Host Machine

```bash
# Connect to database
docker exec -it postgres-production psql -U postgres -d michaelschiemer

# Run SQL query
docker exec postgres-production psql -U postgres -d michaelschiemer -c "SELECT version();"
```

#### From Application Container

```bash
# Connection string format
postgresql://postgres:password@postgres-production:5432/michaelschiemer
```

### Backup Management

#### Manual Backup

```bash
# Trigger manual backup
docker exec postgres-production-backup /scripts/backup.sh

# List backups
ls -lh backups/

# Example output:
# postgres_michaelschiemer_20250130_020000.sql.gz
```

#### Restore from Backup

```bash
# List available backups
docker exec postgres-production-backup ls -lh /backups

# Restore specific backup
docker exec -it postgres-production-backup /scripts/restore.sh /backups/postgres_michaelschiemer_20250130_020000.sql.gz

# ⚠️ WARNING: This will DROP and RECREATE the database!
```

## Network Isolation

This stack uses its own isolated network:
- **Network**: `postgres-production-internal`
- **Purpose**: Isolate Production database from other services
- **Access**: Only services explicitly connected to this network can access the database

**Connecting Application Stack**:
```yaml
# In deployment/stacks/production/docker-compose.production.yml
networks:
  postgres-production-internal:
    external: true
    name: postgres-production-internal
```

## Security

### Network Isolation
- PostgreSQL only accessible via `postgres-production-internal` network
- No external ports exposed
- Service-to-service communication only

### Authentication
- Strong password required (generated with `openssl rand -base64 32`)
- No default passwords
- Password stored in environment variables only

## Monitoring

### Health Checks

```bash
# Check service health
docker compose ps

# Expected: Both services "healthy"

# Manual health check
docker exec postgres-production pg_isready -U postgres -d michaelschiemer
```

### Resource Usage

```bash
# Database container stats
docker stats postgres-production --no-stream

# Disk usage
docker exec postgres-production du -sh /var/lib/postgresql/data
```

### Logs

```bash
# PostgreSQL logs
docker compose logs postgres-production

# Backup logs
docker compose logs postgres-production-backup

# Real-time monitoring
docker compose logs -f
```

## Troubleshooting

### Database Won't Start

```bash
# Check logs
docker compose logs postgres-production

# Common issues:
# 1. Invalid configuration
docker exec postgres-production postgres --check

# 2. Permission issues
docker exec postgres-production ls -la /var/lib/postgresql/data
```

### Connection Refused from Application

```bash
# 1. Check PostgreSQL is running
docker compose ps postgres-production

# 2. Verify network
docker network inspect postgres-production-internal | grep postgres-production

# 3. Check if application is connected to network
docker network inspect postgres-production-internal | grep app
```

## Differences from Staging Stack

| Aspect | Production | Staging |
|--------|-----------|---------|
| **Container Name** | postgres-production | postgres-staging |
| **Network** | postgres-production-internal | postgres-staging-internal |
| **Volume** | postgres-production-data | postgres-staging-data |
| **Database** | michaelschiemer | michaelschiemer_staging |
| **Backup Retention** | 7 days (configurable) | 7 days (configurable) |

## Additional Resources

- **PostgreSQL Documentation**: https://www.postgresql.org/docs/16/
- **Performance Tuning**: https://wiki.postgresql.org/wiki/Performance_Optimization
- **Backup Best Practices**: https://www.postgresql.org/docs/16/backup.html