Docker - Rails应用程序无法连接到链接的Postgres容器（似乎没有运行）

Question

我一直在关注如何使用Docker设置Rails开发环境的指南：Setting Up A Rails Development Environment Using Docker。

我一路上遇到了一些障碍，但是我已经设法完成了大部分工作，直到运行Rails迁移的步骤。运行命令docker-compose run web rake db:migrate会产生以下结果：

rake aborted!
PG::ConnectionBad: could not connect to server: Connection refused
    Is the server running on host "localhost" (::1) and accepting
    TCP/IP connections on port 5432?
could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?

搬运工-compose.yml：

version: '2'
services:
  db:
    image: postgres
    volumes:
      - ./pgdata:/pgdata
    environment:
      POSTGRES_DB: myapp_development
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD:
      PGDATA: /pgdata
  web:
    build: .
    command: bundle exec rails server --port 5000 --binding 0.0.0.0
    volumes_from:
      - container:myapp-web-sync:rw
      - container:myapp-bundle-sync:rw
    volumes:
      - ./keys:/root/.ssh/
    ports:
      - "5000:5000"
    environment:
      REDIS_URL: redis://redis:6379
      GEM_HOME: /bundle
    links:
      - db
      - redis
volumes:
  myapp-web-sync:
    external: true
  myapp-bundle-sync:
    external: true

Answer 1

您尝试连接到localhost:5432，换句话说，您尝试连接到web容器，但您的观点是db。只需在应用程序中指定数据库主机，如db