title: Pull docker image behind a corporate firewall throws "Server error: Status 0 while fetching image layer"
body: <p>I can't download images behind the corporate firewall.</p>
  
  <p><a href="https://stackoverflow.com/questions/23111631/cannot-download-docker-images-behind-a-proxy">This post</a> helped me to fix the <strong><em>no address associated with hostname</em></strong> error. I use Cntlm for proxy user authentication. </p>
  
  <pre><code>$ lsb_release -a
  No LSB modules are available.
  Distributor ID: Ubuntu
  Description:    Ubuntu 15.10
  Release:    15.10
  Codename:   wily
  
  $ docker -v
  Docker version 1.9.1, build a34a1d5
  
  $ sudo docker search ubuntu
  Error response from daemon: Get https://index.docker.io/v1/search?q=ubuntu: dial tcp: lookup index.docker.io: No address associated with hostname
  $ sudo mv /tmp/http-proxy.conf /etc/systemd/system/docker.service.d/http-proxy.conf
  $ cat /etc/systemd/system/docker.service.d/http-proxy.conf 
  [Service]
  Environment="HTTP_PROXY=http://localhost:3128/"
  
  $ sudo systemctl daemon-reload
  $ sudo systemctl restart docker
  $ sudo docker search ubuntu | sed -e 1b -e '$!d'
  NAME                              DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
  esycat/ubuntu                     Ubuntu LTS                                      0                    [OK]
  </code></pre>
  
  <p>The pull request interacts with the server, finds the endpoint and fails with: <strong><em>Server error: Status 0 while fetching image layer</em></strong>.</p>
  
  <pre><code>$ sudo docker pull ubuntu
  Using default tag: latest
  latest: Pulling from library/ubuntu
  
  fcee8bcfe180: Pulling fs layer 
  4cdc0cbc1936: Pulling fs layer 
  d9e545b90db8: Pulling fs layer 
  c4bea91afef3: Pulling fs layer 
  Pulling repository docker.io/library/ubuntu
  af88597ec24b: Pulling image (latest) from docker.io/library/ubuntu, endpoint: https://registry-1.docker.iaf88597ec24b: Error pulling image (latest) from docker.io/library/ubuntu, endpoint: https://registry-1.docker.io/v1/, Server error: Status 0 while fetching image layer (895b070402bd7d26d9595e939422c598e8cc1f4adaf88597ec24b: Error pulling image (latest) from docker.io/library/ubuntu, Server error: Status 0 while fetching image layer (895b070402bd7d26d9595e939422c598e8cc1f4ade1b34e2a9659138ffe3c5c9) 
  
  Error pulling image (latest) from docker.io/library/ubuntu, Server error: Status 0 while fetching image layer (895b070402bd7d26d9595e939422c598e8cc1f4ade1b34e2a9659138ffe3c5c9)
  </code></pre>
  
  <p>Any idea why the pull request fails? Does a pull request use a <em>different</em> port and/or protocol? Is something <em>missing</em> in my configuration file?</p>