title: Certificate error in docker
body: <p>I'm behind a corporate firewall and have installed Docker on an Ubuntu 14.04 LTS server. Following instructions at <a href="http://docs.docker.com/linux/step_one/" rel="nofollow">http://docs.docker.com/linux/step_one/</a>.</p>
  
  <p>Things seemed to be OK:-</p>
  
  <pre><code>$ docker version
  Client:
   Version:      1.9.1
   API version:  1.21
   Go version:   go1.4.2
   Git commit:   a34a1d5
   Built:        Fri Nov 20 13:12:04 UTC 2015
   OS/Arch:      linux/amd64
  
  Server:
   Version:      1.9.1
   API version:  1.21
   Go version:   go1.4.2
   Git commit:   a34a1d5
   Built:        Fri Nov 20 13:12:04 UTC 2015
   OS/Arch:      linux/amd64
  </code></pre>
  
  <p>... but I can't pull and run any images. Example:-</p>
  
  <pre><code>$ docker run hello-world
  </code></pre>
  
  <p>gives:</p>
  
  <blockquote>
    <p>Error while pulling image: Get
    <a href="https://index.docker.io/v1/repositories/library/hello-world/images" rel="nofollow">https://index.docker.io/v1/repositories/library/hello-world/images</a>:
    x509: certificate is valid for FG3K6C3A15800002, not index.docker.io</p>
  </blockquote>
  
  <p>Have spent ages searching around - I don't understand what the issue is - I've set http_proxy and https_proxy env vars but not sure what to try next. The docs don't mention any certificate requirements.</p>
  
  <p>Any help appreciated!</p>