docker-compose.yml

version: '3.8'
services:
  leader:
    image: bitnami/postgresql:13.5.0
    ports:
      - 5433:5432
    volumes:
      - leader_data:/bitnami/postgresql
    environment:
      - POSTGRESQL_REPLICATION_MODE=master
      - POSTGRESQL_REPLICATION_USER=postgres
      - POSTGRESQL_REPLICATION_PASSWORD=s3cret
      - POSTGRESQL_PASSWORD=s3cret
      - POSTGRESQL_DATABASE=test_db
  follower:
    image: bitnami/postgresql:13.5.0
    ports:
      - 5434:5432
    depends_on:
      - leader
    environment:
      - POSTGRESQL_REPLICATION_MODE=slave
      - POSTGRESQL_REPLICATION_USER=postgres
      - POSTGRESQL_REPLICATION_PASSWORD=s3cret
      - POSTGRESQL_MASTER_HOST=leader
      - POSTGRESQL_PASSWORD=s3cret
  pgpool:
    image: bitnami/pgpool:4.3.3
    ports:
      - 5435:5432
    depends_on:
      - leader
    environment:
      - PGPOOL_BACKEND_NODES=0:leader:5432:4:primary:ALWAYS_PRIMARY,1:follower:5432:6:replica
      - PGPOOL_POSTGRES_USERNAME=postgres
      - PGPOOL_POSTGRES_PASSWORD=s3cret
      - PGPOOL_ADMIN_USERNAME=admin
      - PGPOOL_ADMIN_PASSWORD=s3cret
      - PGPOOL_ENABLE_LOAD_BALANCING=yes
      - PGPOOL_ENABLE_STATEMENT_LOAD_BALANCING=yes
      - PGPOOL_NUM_INIT_CHILDREN=10
      - PGPOOL_MAX_POOL=1
      - PGPOOL_SR_CHECK_USER=postgres
      - PGPOOL_SR_CHECK_PASSWORD=s3cret
volumes:
  leader_data: