title: Gitlab CI /var/run/docker.sock: write: broken pipe
body: <p>Trying to set up a runner and coming up with this issue:</p>
  <pre><code>Running with gitlab-ci-multi-runner 1.10.4 (b32125f)
  Using Docker executor with image php:5.6 ...
  ERROR: Failed to create container volume for /builds/ppw write unix @-&gt;/var/run/docker.sock: write: broken pipe
  ERROR: Preparation failed: write unix @-&gt;/var/run/docker.sock: write: broken pipe
  Will be retried in 3s ...
  Using Docker executor with image php:5.6 ...
  ERROR: Failed to create container volume for /builds/ppw write unix @-&gt;/var/run/docker.sock: write: broken pipe
  ERROR: Preparation failed: write unix @-&gt;/var/run/docker.sock: write: broken pipe
  Will be retried in 3s ...
  Using Docker executor with image php:5.6 ...
  ERROR: Failed to create container volume for /builds/ppw write unix @-&gt;/var/run/docker.sock: write: broken pipe
  ERROR: Preparation failed: write unix @-&gt;/var/run/docker.sock: write: broken pipe
  Will be retried in 3s ...
  ERROR: Build failed (system failure): write unix @-&gt;/var/run/docker.sock: write: broken pipe
  </code></pre>
  <p>I've tried downgrading the <code>gitlab-ci-multi-runner</code> but I still have the same issue - <code>broken pipe</code>.</p>
  <p>System is running: Ubuntu 16.04.1 LTS</p>
  <h3>My .gitlab-ci.yml</h3>
  <pre><code>before_script:
  # Install dependencies
  - bash ci/docker_install.sh &gt; /dev/null
  # We test PHP5.6
  test:5.6:
    image: php:5.6
    script:
    - phpunit --configuration phpunit_myapp.xml
  # We test PHP7.0
  test:7.0:
    image: php:7.0
    script:
    - phpunit --configuration phpunit_myapp.xml
  </code></pre>
  <h3>My ci/docker_install.sh</h3>
  <pre><code>#!/bin/bash
  # We need to install dependencies only for Docker
  [[ ! -e /.dockerenv ]] &amp;&amp; exit 0
  set -xe
  # Install git (the php image doesn't have it) which is required by composer
  apt-get update -yqq
  apt-get install git -yqq
  # Install phpunit, the tool that we will use for testing
  curl --location --output /usr/local/bin/phpunit https://phar.phpunit.de/phpunit.phar
  chmod +x /usr/local/bin/phpunit
  </code></pre>
  <p>Any help would be appreciated, I have tried reading up here: <a href="https://stackoverflow.com/questions/40126748/gitlabci-build-failed-docker-sock-write-broken-pipe">GitlabCI build failed, docker.sock: write: broken pipe</a></p>
  <p>When i do <code>docker ps</code> I don't have any containers listed.</p>
  <pre><code>$ docker ps
  CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
  </code></pre>