title: Gitlab run docker inside docker
body: <p>I'm using gitlab 9.3.3-ce.0 and gitlab runner with docker executor. I want to build images inside this docker-executor. How to do it?</p>
  
  <p>I'm trying to connect to outer docker using this section inside <code>/etc/gitlab-runner/config.toml</code>:</p>
  
  <pre><code>[runners.docker]
      tls_verify = false
      image = "java:8"
      privileged = true
      disable_cache = false
      volumes = ["/var/images", "/var/lib/docker:/var/lib/docker", 
                 "/var/run/docker.sock:/var/run/docker.sock", 
                 "/usr/bin/docker:/usr/bin/docker"]
      shm_size = 0
  </code></pre>
  
  <p>But when I try to execute inside docker <code>docker info</code> I get: </p>
  
  <pre><code>/usr/bin/docker: No such file or directory
  </code></pre>
  
  <p>But it should exist:</p>
  
  <pre><code>$ which docker
  /usr/bin/docker
  </code></pre>