Docker-compose Postgres 连接被拒绝

Question

我在 docker-compose 上使用 pg-admin 和 GO 运行 Postgres DB。

问题：我可以从pg-admin 连接到Postgres。但无法从Go 建立连接。

我尝试了不同的身份验证字符串组合，但它不起作用。字符串格式与此处 https://github.com/karlkeefer/pngr 相同 - 但容器名称不同 - database

（错误）连接 URL：

backend_1         | 2021/08/08 14:24:40 DB connection: database://main:fugZwypczB94m0LP7CcH@postgres:5432/temp_db?sslmode=disable
backend_1         | 2021/08/08 14:24:40 Unalble to open DB connection: dial tcp 127.0.0.1:5432: connect: connection refused

（URI 生成与此处相同https://github.com/karlkeefer/pngr）

Docker：

version: '3.8'
services:
  backend:
    restart: always
    build: 
      context: backend
      target: dev
    volumes:
      - ./backend:/root
    ports:
      - "5000:5000"
    env_file: .env
    depends_on: 
      - database
  database:
    build: database
    restart: always
    environment:
      POSTGRES_DB: ${POSTGRES_DB}
      POSTGRES_USER: ${POSTGRES_USER}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
      PGDATA: /var/lib/postgresql/data
    volumes:
      - ./database/data:/var/lib/postgresql/data
      - ./logs/databse:/var/log/postgresql
      - ./database/migrations:/docker-entrypoint-initdb.d/migrations
    ports:
      - "5432:5432"
  database-admin:
    image: dpage/pgadmin4:5.5
    restart: always
    environment:
      PGADMIN_DEFAULT_EMAIL: ${PG_ADMIN_EMAIL}
      PGADMIN_DEFAULT_PASSWORD: ${PG_ADMIN_PASSWORD}
      PGADMIN_LISTEN_PORT: 80
    ports:
      - "8080:80"
    volumes:
      - ./database/admin:/var/lib/pgadmin
    links:
      - "database:pgsql-server"
    depends_on: 
      - database
volumes:
  database:
  database-admin:

环境：

POSTGRES_HOST=postgres
POSTGRES_PORT=5432
POSTGRES_DB=temp_db
POSTGRES_USER=main
POSTGRES_PASSWORD=fugZwypczB94m0LP7CcH
PG_ADMIN_EMAIL=admin@temp.com
PG_ADMIN_PASSWORD=ayzi2ta8f1TnX3vKQSN1
PG_ADMIN_PORT=80

GO代码：

db, err = sqlx.Open("postgres", str)

str

func buildConnectionString() string {
    user := os.Getenv("POSTGRES_USER")
    pass := os.Getenv("POSTGRES_PASSWORD")
    if user == "" || pass == "" {
        log.Fatalln("You must include POSTGRES_USER and POSTGRES_PASSWORD environment variables")
    }
    host := os.Getenv("POSTGRES_HOST")
    port := os.Getenv("POSTGRES_PORT")
    dbname := os.Getenv("POSTGRES_DB")
    if host == "" || port == "" || dbname == "" {
        log.Fatalln("You must include POSTGRES_HOST, POSTGRES_PORT, and POSTGRES_DB environment variables")
    }

    str := fmt.Sprintf("database://%s:%s@%s:%s/%s?sslmode=disable", user, pass, host, port, dbname)

    log.Println("DB connection: " + str)

    return str
}

提前致谢！

Answer 1

您将数据库主机名引用为postgres (POSTGRES_HOST=postgres)，这很好，但容器/服务名称为database。

要么将 compose.yaml 中的名称从 database 更改为 postgres，要么添加明确的 hostname 字段：

database:
  build: database
  restart: always
  hostname: postgres   # <- add this

---

您可能还想为多个容器服务添加一个专用的network 以相互交谈（或阻止其他人交谈）。为此，请将其添加到您要使用特定网络的每个服务中，例如

database:
  # ...

  networks:
    - mynet

backend:
  # ...

  networks:
    - mynet

并在 compose.yaml 末尾定义网络

networks:
  mynet:
    name: my-shared-db-network