docker-compose.yml

networks:
  local-4eum-network:
    name: local-4eum-network
    driver: bridge

services:
  postgres-primary:
    image: postgres:15
    container_name: local-postgres-primary
    restart: unless-stopped
    ports:
      - "5433:5432"
    environment:
      POSTGRES_USER: ${POSTGRES_USER:-app_user}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-app_password}
      POSTGRES_DB: ${POSTGRES_DB:-app_db}
    command:
      - bash
      - -c
      - |
        # init 스크립트를 컨테이너 내부에 직접 생성 (Windows CRLF 문제 회피)
        printf '%s\n' '#!/bin/bash' 'echo "host replication all 0.0.0.0/0 md5" >> "$$PGDATA/pg_hba.conf"' \
          > /docker-entrypoint-initdb.d/00-init-hba.sh
        chmod +x /docker-entrypoint-initdb.d/00-init-hba.sh

        cat > /docker-entrypoint-initdb.d/01-init-replication.sql << 'EOF'
        ALTER USER app_user REPLICATION;
        SELECT pg_create_physical_replication_slot('replica_slot')
          WHERE NOT EXISTS (SELECT 1 FROM pg_replication_slots WHERE slot_name = 'replica_slot');
        EOF

        exec docker-entrypoint.sh postgres \
          -c wal_level=replica \
          -c max_wal_senders=10 \
          -c max_replication_slots=10 \
          -c hot_standby=on
    volumes:
      - primary-data:/var/lib/postgresql/data
    healthcheck:
      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER:-app_user} -d ${POSTGRES_DB:-app_db}"]
      interval: 5s
      timeout: 5s
      retries: 10
      start_period: 10s
    networks:
      - local-4eum-network

  postgres-replica:
    image: postgres:15
    container_name: local-postgres-replica
    restart: unless-stopped
    ports:
      - "5434:5432"
    depends_on:
      postgres-primary:
        condition: service_healthy
    environment:
      POSTGRES_USER: ${POSTGRES_USER:-app_user}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-app_password}
      PGPASSWORD: ${POSTGRES_PASSWORD:-app_password}
    command:
      - bash
      - -c
      - |
        # 기존 데이터 정리
        rm -rf /var/lib/postgresql/data/*

        # Primary가 replication 준비될 때까지 대기 (최대 60초)
        echo "Waiting for primary to be ready for replication..."
        until pg_basebackup \
          --pgdata=/var/lib/postgresql/data \
          --write-recovery-conf \
          --slot=replica_slot \
          --host=postgres-primary \
          --port=5432 \
          --username=$$POSTGRES_USER
        do
          echo "Waiting for primary..."
          sleep 3
        done

        # 데이터 디렉토리가 비어있으면 실패
        if [ ! -f /var/lib/postgresql/data/PG_VERSION ]; then
          echo "ERROR: Failed to create base backup"
          exit 1
        fi

        chown -R postgres:postgres /var/lib/postgresql/data
        chmod 700 /var/lib/postgresql/data
        exec gosu postgres postgres
    volumes:
      - replica-data:/var/lib/postgresql/data
    networks:
      - local-4eum-network

volumes:
  primary-data:
  replica-data: