This Docker Compose configuration defines a multi-container setup for running Directus (a headless CMS) alongside two PostgreSQL databases, one acting as the primary server and the other as a replica. The goal is to achieve replication between the two PostgreSQL instances.

docker-compose.yml

# This Docker Compose file defines three services: directus, postgres-primary, and postgres-replica.
# directus service runs Directus, a headless CMS, and depends on the postgres-primary service.
# postgres-primary service is the primary PostgreSQL database server configured with various environment variables and PostgreSQL settings.
# postgres-replica service is the replica PostgreSQL server configured for streaming replication from the primary server.
# The services are connected to a custom network called mynetwork.
# PostgreSQL settings such as shared buffers, work memory, and replication configurations are set for both primary and replica servers.
# The replication configuration specifies the streaming replication mode and replication user details.
################
# Note: Despite the provided configuration, replication is not happening as expected. Can anyone help diagnose the issue?
################
version: "3.7"
services:
  directus:
    image: directus/directus:latest
    container_name: directus
    depends_on:
      - postgres-primary
    ports:
      - "8055:8055"
    environment:
      KEY: "255d861b-5ea1-5996-9aa3-922530ec40b1"
      SECRET: "6116487b-cda1-52c2-b5b5-c8022c45e263"

      DB_CLIENT: "pg"
      DB_HOST: "postgres-primary"
      DB_PORT: "5432"
      DB_DATABASE: "directusdb"
      DB_USER: "finisa"
      DB_PASSWORD: "8Fp2Ks9jE"
      ADMIN_EMAIL: "dev@bol.com.br"
      ADMIN_PASSWORD: "bol"
    networks:
      - mynetwork
  postgres-primary:
    image: postgres:16
    environment:
      POSTGRES_USER: finisa
      POSTGRES_PASSWORD: 8Fp2Ks9jE
      POSTGRES_DB: directusdb
      PGDATA: /var/lib/postgresql/data
      POSTGRES_SHARED_BUFFERS: 2GB
      POSTGRES_WORK_MEM: 128MB
      POSTGRES_MAINTENANCE_WORK_MEM: 1GB
      POSTGRES_EFFECTIVE_CACHE_SIZE: 4GB
      POSTGRES_MAX_CONNECTIONS: 100
      POSTGRES_AUTOVACUUM_VACUUM_SCALE_FACTOR: 0.2
      POSTGRES_AUTOVACUUM_ANALYZE_SCALE_FACTOR: 0.1
      POSTGRES_AUTOVACUUM_VACUUM_COST_LIMIT: -1
      POSTGRES_MAX_WAL_SENDERS: 4
      POSTGRES_MAX_REPLICATION_SLOTS: 4
      POSTGRES_WAL_LEVEL: logical
      POSTGRES_LOCALE: "pt_BR.utf8"
      POSTGRES_TIMEZONE: "America/Sao_Paulo"
      LANG: "pt_BR.UTF-8"
    command:
      - "postgres"
      - "-c"
      - "shared_buffers=2GB"
      - "-c"
      - "work_mem=128MB"
      - "-c"
      - "maintenance_work_mem=1GB"
      - "-c"
      - "effective_cache_size=4GB"
      - "-c"
      - "max_connections=100"
      - "-c"
      - "autovacuum_vacuum_scale_factor=0.2"
      - "-c"
      - "autovacuum_analyze_scale_factor=0.1"
      - "-c"
      - "autovacuum_vacuum_cost_limit=-1"
      - "-c"
      - "wal_level=logical"
      - "-c"
      - "max_wal_senders=4"
      - "-c"
      - "max_replication_slots=4"
    ports:
      - "5432:5432"
    volumes:
      - postgres-data-primary:/var/lib/postgresql/data
    networks:
      - mynetwork
    restart: always

  postgres-replica:
    image: postgres:16
    environment:
      POSTGRES_USER: finisa
      POSTGRES_PASSWORD: 8Fp2Ks9jE
      POSTGRES_DB: directusdb
      PGDATA: /var/lib/postgresql/data
      POSTGRES_SHARED_BUFFERS: 2GB
      POSTGRES_WORK_MEM: 128MB
      POSTGRES_MAINTENANCE_WORK_MEM: 1GB
      POSTGRES_EFFECTIVE_CACHE_SIZE: 4GB
      POSTGRES_MAX_CONNECTIONS: 100
      POSTGRES_AUTOVACUUM_VACUUM_SCALE_FACTOR: 0.2
      POSTGRES_AUTOVACUUM_ANALYZE_SCALE_FACTOR: 0.1
      POSTGRES_AUTOVACUUM_VACUUM_COST_LIMIT: -1
      POSTGRES_MAX_WAL_SENDERS: 4
      POSTGRES_MAX_REPLICATION_SLOTS: 4
      POSTGRES_WAL_LEVEL: logical
      POSTGRES_LOCALE: "pt_BR.utf8"
      POSTGRES_TIMEZONE: "America/Sao_Paulo"
      LANG: "pt_BR.UTF-8"
      POSTGRES_REPLICATION_MODE: streaming
      POSTGRES_REPLICATION_USER: finisa
      POSTGRES_REPLICATION_PASSWORD: 8Fp2Ks9jE
      POSTGRES_PRIMARY_HOST: postgres-primary
      POSTGRES_PRIMARY_PORT: 5432
    command:
      - "postgres"
      - "-c"
      - "shared_buffers=2GB"
      - "-c"
      - "work_mem=128MB"
      - "-c"
      - "maintenance_work_mem=1GB"
      - "-c"
      - "effective_cache_size=4GB"
      - "-c"
      - "max_connections=100"
      - "-c"
      - "autovacuum_vacuum_scale_factor=0.2"
      - "-c"
      - "autovacuum_analyze_scale_factor=0.1"
      - "-c"
      - "autovacuum_vacuum_cost_limit=-1"
      - "-c"
      - "max_wal_senders=4"
      - "-c"
      - "max_replication_slots=4"
    ports:
      - "5433:5432"
    volumes:
      - postgres-data-replica:/var/lib/postgresql/data
    networks:
      - mynetwork
    restart: always

volumes:
  postgres-data-primary:
  postgres-data-replica:

networks:
  mynetwork: