用于带有码头的GitLab管道的PGHOST :由docker-组合创建的postgres的dind

Question

我有一个坞-撰写文件，它初始化postgres和postgres迁移服务。我还想在gitlab管道上针对我的插件-编写烘焙postgres服务运行测试，但我无法通过本地主机连接到pg_db。在我的代码中，我使用pgx包。在我的本地机器上，对PGHOST变量使用localhost没有问题。

因此，我的主要问题是在PGHOST变量中放置什么主机，以便测试在gitlab管道中使用postgres连接。

docker-compose.yml

version: "3.3"
services:
    pg_db:
      container_name: pg_db
      image: postgres:13.2-alpine
      environment:
        - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
        - POSTGRES_USER=${POSTGRES_USER}
        - POSTGRES_DB=${POSTGRES_DB}
        - POSTGRES_SSLMODE=${POSTGRES_SSLMODE}
        - POSTGRES_HOST_AUTH_METHOD=${POSTGRES_HOST_AUTH_METHOD}
      ports:
        - ${POSTGRES_PORT}:5432
      restart: always
      deploy:
        resources:
          limits:
            cpus: '1'
            memory: 4G
      networks:
        - postgres
        - backend

    #init db
    store-init:
      image: x:latest
      container_name: store-init
      environment:
        - PGHOST=pg_db
        - PGUSER=${POSTGRES_USER}
        - PGPASSWORD=${POSTGRES_PASSWORD}
        - PGDATABASE=${POSTGRES_DB}
        - PGPORT=${POSTGRES_PORT}
      restart: on-failure
      depends_on:
        - pg_db
      networks:
        - postgres
        - backend

networks:
  backend:
  postgres:
    driver: bridge

这里是我的gitlab-ci.yml的一个重要部分

services:
    - docker:dind

stages:
  - test

test:
  stage: test
  image: golang:1.17-alpine3.15
  variables:
    PGHOST: localhost
  before_script:
    - apk update && apk add make git openssh g++
    - apk add --no-cache docker-compose
    - git config --global user.email "$GITLAB_USER_EMAIL" && git config --global user.name "$GITLAB_USER_NAME"
    - mkdir -p ~/.ssh && echo "$SSH_PRIVATE_KEY" > ~/.ssh/id_rsa && chmod -R 600 ~/.ssh && ssh-keyscan -t rsa ssh.x >> ~/.ssh/known_hosts
  script:
    - cp .env.example .env
    - docker-compose up -d
    - sleep 30 # a temporary line to get the logs
    - cat /etc/hosts # debug line
    - docker-compose port pg_db 5432 # debug line
    - netstat -a # debug line
    - docker-compose ps # debug line
    - go test -v -timeout 30s ./... -tags=withDB

  only:
    - merge_request
    - dev
    - master

我要的原木

variables: 
   PGHOST: localhost

$ cp .env.example .env
$ docker-compose up -d
Recreating alp-logger_pg_db_1 ... 
Recreating alp-logger_pg_db_1 ... done
store-init is up-to-date
$ sleep 30
$ cat /etc/hosts
127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.17.0.2  runner-lxzkchpx-project-304-concurrent-0
$ docker-compose port pg_db 5432
0.0.0.0:5432
$ netstat -a
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       
tcp        0      0 runner-lxzkchpx-project-304-concurrent-0:50294 static.124.194.21.65.clients.your-server.de:ssh TIME_WAIT   
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags       Type       State         I-Node Path
$ docker-compose ps
   Name                 Command              State           Ports         
---------------------------------------------------------------------------
pg_db        docker-entrypoint.sh postgres   Up      0.0.0.0:5432->5432/tcp
store-init   ./alp-store                     Up                            

和连接到postgres db的错误：

failed to connect to `host=localhost user=test database=test`: dial error (dial tcp [::1]:5432: connect: cannot assign requested address)

调试命令的日志是相同的，所以我将跳过它们。我所犯的错误

variables: 
    PGHOST: pg_db

对于任何其他命名主机，如docker。

failed to connect to `host=pg_db user=test database=test`: hostname resolving error (lookup pg_db on 1.1.1.1:53: no such host)

我所犯的错误

variables: 
    PGHOST: 127.0.0.1

failed to connect to `host=127.0.0.1 user=test database=test`: dial error (dial tcp 127.0.0.1:5432: connect: connection refused)

Answer 1

在本地机器上运行容器与在GitLab中使用docker:dind运行容器之间的一个重要区别是，容器在'localhost‘上不可用--它们在docker:dind容器上可用。

如果您想要与这个容器对话，在您的场景中，postgres容器将在docker:5432上可用(docker是您的postgres容器有其端口映射的docker:dind容器的主机名)。

简单HTTP服务容器的说明

作为一个简化的示例，如果要在本地运行带有端口映射的容器strm/helloworld-http，下面的工作如下：

docker run -d --rm -p 80:80 strm/helloworld-http
# give it some time to startup
curl http://localhost  # this works

但是，GitLab中的相同设置并不是：

myjob:
  variables:  # these variables are not necessarily required
    DOCKER_TLS_CERTDIR: ""
    DOCKER_HOST: "tcp://docker:2375"
  services:
    - docker:dind
  script:
    - docker run -d --rm -p 80:80 strm/helloworld-http
    - sleep 10
    - curl http://localhost  # Fails!

一个解决方法是使用docker主机名，而不是：

script:
    - docker run -d --rm -p 80:80 strm/helloworld-http
    - sleep 10
    - curl http://docker  # works!