系统：Ubuntu 18.04.1 LTS

gitlab版本：11.9

使用gitlab服务器域名：https://gitlab.example.com

需要使用到url和token:gitlab服务器地址+/admin/runners

要在GNU / Linux下注册Runner：

1. 运行以下命令：

   gitlab-runner register

2. 输入您的GitLab实例URL：

    Please enter the gitlab-ci coordinator URL (e.g. https://gitlab.com )
    https://gitlab.com
   

3. 输入您获得的令牌以注册Runner：

   Please enter the gitlab-ci token for this runner
    xxx

4. 输入Runner的描述，您可以稍后在GitLab的UI中更改：

   Please enter the gitlab-ci description for this runner
   [hostame] my-runner

5. 输入与Runner关联的标签，您可以稍后在GitLab的UI中更改：

   Please enter the gitlab-ci tags for this runner (comma separated):
   my-tag,another-tag

6. 输入Runner执行程序：

   Please enter the executor: ssh, docker+machine, docker-ssh+machine, kubernetes, docker, parallels, virtualbox, docker-ssh, shell:
   docker

7. 如果您选择Docker作为执行程序，则会要求您将默认图像用于未在其中定义的项目.gitlab-ci.yml：

   Please enter the Docker image (eg. ruby:2.1):
   alpine:latest

  第五步报错,报错信息如下：

ERROR: Registering runner... failed                 runner=6HkNBVen status=couldn't execute POST against https://gitlab.example.com/api/v4/runners: Post https://gitlab.example.com/api/v4/runners: x509: certificate signed by unknown authority
PANIC: Failed to register this runner. Perhaps you are having network problems

证书签名错误,在网上找了许多办法还是不行，解决办法：

gitlab-runner register \
  --non-interactive \
  --tls-ca-file=/etc/gitlab/ssl/gitlab.example.com.crt  \
  --url "https://gitlab.example.com/" \
  --registration-token "6HkNBVenPd9sMyd2HzhK" \
  --executor "docker" \
  --docker-image maven:latest \
  --description "runner " \
  --tag-list "run" \
  --run-untagged \
  --locked="false"

找到gitlab文件夹下,就看到了,把证书文件带上

其他版本注册方式：

https://docs.gitlab.com/11.9/runner/register/index.html