version: '3.8'

# Shared PostgreSQL Database
# Purpose: Centralized database for all homelab applications
# Port: 5432
# GPU: No
# Storage: SSD (PostgreSQL data and backups)

services:
  postgres-shared:
    image: postgres:16-alpine
    container_name: postgres-shared
    restart: unless-stopped
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U postgres"]
      start_period: 20s
      interval: 30s
      retries: 5
      timeout: 5s
    ports:
      - "5432:5432"
    volumes:
      - /home/jpmschweitzer/docker-data/postgres-shared/data:/var/lib/postgresql/data
      - /home/jpmschweitzer/docker-data/postgres-shared/backups:/backups
    environment:
      POSTGRES_PASSWORD: ${POSTGRES_ADMIN_PASSWORD:?admin password required}
      TZ: Europe/Amsterdam

      # Performance tuning (adjust based on available RAM)
      # Shared buffers: 25% of RAM allocated to PostgreSQL
      POSTGRES_SHARED_BUFFERS: 512MB
      # Effective cache: 50-75% of RAM allocated to PostgreSQL
      POSTGRES_EFFECTIVE_CACHE_SIZE: 2GB
      # Max connections: adjust based on number of applications
      POSTGRES_MAX_CONNECTIONS: 200
    deploy:
      resources:
        limits:
          cpus: '2.0'
          memory: 2G
        reservations:
          memory: 512M
    networks:
      - docker-dataplane

networks:
  docker-dataplane:
    external: true
    name: docker-dataplane

# Setup Instructions:
#
# 1. Create directories:
#    mkdir -p ~/docker-data/postgres-shared/{data,backups}
#
# 2. Deploy stack via core-api (recommended) or docker-compose
#
# 3. Initialize databases (run ONCE after first deployment):
#    docker exec -i postgres-shared psql -U postgres <<'EOF'
#      -- Authentik database
#      CREATE DATABASE authentik;
#      CREATE USER authentik_user WITH PASSWORD 'F//j0ktck7cX06Vfgh0YXceONOtlSsHvadqROICeDx8=';
#      GRANT ALL PRIVILEGES ON DATABASE authentik TO authentik_user;
#      \c authentik
#      GRANT ALL ON SCHEMA public TO authentik_user;
#      ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT ALL ON TABLES TO authentik_user;
#      ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT ALL ON SEQUENCES TO authentik_user;
#
#      -- Gitea database
#      \c postgres
#      CREATE DATABASE gitea;
#      CREATE USER gitea_user WITH PASSWORD 'cCav64d76NX1zdEEAbVOM9uvao14aY8HojjNdxsSpMM=';
#      GRANT ALL PRIVILEGES ON DATABASE gitea TO gitea_user;
#      \c gitea
#      GRANT ALL ON SCHEMA public TO gitea_user;
#      ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT ALL ON TABLES TO gitea_user;
#      ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT ALL ON SEQUENCES TO gitea_user;
#    EOF
#
# 4. Verify deployment:
#    docker exec postgres-shared pg_isready
#    docker exec postgres-shared psql -U postgres -c '\l'
#
# Database Connection Examples:
#
# From containers on docker-dataplane network:
#   Host: postgres-shared
#   Port: 5432
#   Database: authentik (or gitea, etc.)
#   User: authentik_user (or gitea_user, etc.)
#   Password: <app-specific-password>
#
# From host machine:
#   psql -h localhost -U authentik_user -d authentik
#
# Monitoring:
#
# Active connections per database:
#   docker exec postgres-shared psql -U postgres -c \
#     "SELECT datname, numbackends FROM pg_stat_database;"
#
# Database sizes:
#   docker exec postgres-shared psql -U postgres -c \
#     "SELECT datname, pg_size_pretty(pg_database_size(datname)) FROM pg_database;"
#
# Backup:
#
# All databases:
#   docker exec postgres-shared pg_dumpall -U postgres | \
#     gzip > ~/docker-data/postgres-shared/backups/all-$(date +%Y%m%d).sql.gz
#
# Single database:
#   docker exec postgres-shared pg_dump -U postgres authentik | \
#     gzip > ~/docker-data/postgres-shared/backups/authentik-$(date +%Y%m%d).sql.gz
#
# Restore:
#   gunzip < backup.sql.gz | docker exec -i postgres-shared psql -U postgres
#
# Maintenance:
#
# Vacuum analyze (optimize performance):
#   docker exec postgres-shared psql -U postgres -c "VACUUM ANALYZE;"
#
# Reindex (if queries slow):
#   docker exec postgres-shared psql -U postgres -d authentik -c "REINDEX DATABASE authentik;"
#
# Resource Usage (expected):
#   CPU: ~0.5-1.5 cores (depends on query load)
#   RAM: ~500MB-1.5GB (depends on active connections and cache)
#   Storage: Grows with data (monitor with: df -h ~/docker-data/postgres-shared)
#
# Applications Using This Database:
#   - Authentik (identity provider)
#   - Gitea (git hosting) - migrated from dedicated instance
#   - Nextcloud (personal cloud storage) - migrated from MariaDB
#   - Future applications as needed