基于docker容器的Postgresql 11主从复制搭建 及切换

以下是一个简化版的Docker容器化PostgreSQL 11主从复制的示例：

1. 准备docker-compose.yml文件:

version: '3'
 
services:
  master:
    image: postgres:11
    environment:
      POSTGRES_DB: primary
      POSTGRES_USER: primaryuser
      POSTGRES_PASSWORD: primarypassword
    volumes:
      - pgdata_master:/var/lib/postgresql/data
    ports:
      - "5432:5432"
 
  slave:
    image: postgres:11
    environment:
      POSTGRES_DB: replica
      POSTGRES_USER: replicauser
      POSTGRES_PASSWORD: replicapassword
      POSTGRES_REPLICA_USER: standbyuser
      POSTGRES_REPLICA_PASSWORD: standbypassword
    volumes:
      - pgdata_slave:/var/lib/postgresql/data
    ports:
      - "5433:5432"
    command: >
      /bin/bash -c "
        echo 'primary_conninfo = 'host=master user=primaryuser password=primarypassword dbname=primary connect_timeout=20' >> /var/lib/postgresql/data/recovery.conf &&
        echo 'primary_slot_name = 'replica_slot' >> /var/lib/postgresql/data/recovery.conf &&
        echo 'trigger_file = /trigger_failover' >> /var/lib/postgresql/data/recovery.conf &&
        echo 'recovery_min_apply_delay = 0' >> /var/lib/postgresql/data/recovery.conf &&
        chmod 600 /var/lib/postgresql/data/recovery.conf &&
        exec docker-entrypoint.sh postgres -c hot_standby=on -c max_standby_streaming_delay=30s
      "

volumes:
  pgdata_master:
  pgdata_slave:

2. 运行\`docker-compose