我在虚拟机上测试了一个gitlab-runner，它运行得很好。我在使用docker-in-docker executor部分学习了这个教程：
https://docs.gitlab.com/ee/ci/docker/using_docker_build.html
当我在我的开发服务器上注册一个配置完全相同的runner时，runner在提交时被调用，但我得到了很多错误：

*** WARNING: Service runner-XXX-project-XX-concurrent-X-docker-X probably didn't start properly.

ContainerStart: Error response from daemon: Cannot link to a non running container: /runner-XXX-project-XX-concurrent-X-docker-X AS /runner-XXX-project-XX-concurrent-X-docker-X-wait-for-service/service (executor_docker.go:1337:1s)

DEPRECATION: this GitLab server doesn't support refspecs, gitlab-runner 12.0 will no longer work with this version of GitLab

$ docker info
error during connect: Get http://docker:2375/v1.39/info: dial tcp: lookup docker on MY.DNS.IP:53: no such host
ERROR: Job failed: exit code 1

我相信所有这些错误都是由于第一次警告。我试着：

• 使用www. example添加第二个DNS www.example.com IP到我的机器，同样的错误
• 在/etc/gitlab-runner/config中手动添加privileged=true。toml，相同的错误，所以它不是由privileged = true参数引起的
• 将tcp：//docker：2375替换为tcp：//localhost：2375，当docker info

gitlab-ci.yml内容：

image: docker:stable
 stages :
  - build

 variables:
  DOCKER_HOST: tcp://docker:2375/
  DOCKER_DRIVER: overlay2

 services:
  - docker:dind

 before_script:
  - docker info

 build-folder1:
   stage: build
   script:
    - docker build -t image1 folder1/
    - docker run --name docker1 -p 3001:5000 -d image1
   only: 
    refs:
     - dev
    changes:
     - folder1/**/*

 build-folder2:
   stage: build
   script:
     - docker build -t image2 folder2/
     - docker run --name docker2 -p 3000:3000 -d image2
   only:
     refs:
      - dev
     changes:
      - folder2/**/*

• 如果分支dev的folder 1被修改，我们构建并运行docker 1
• 如果分支dev的folder 2被修改，我们构建并运行docker 2

dev server上的docker版本：

docker -v 
Docker version 17.03.0-ce, build 3a232c8

dev服务器上的gitlab-runner版本：

gitlab-runner -v
Version:      11.10.1