title: docker.socket: Failed with result 'service-start-limit-hit' after protecting docker daemon socket
body: <p>I followed the steps provided in the documentation <a href="https://docs.docker.com/engine/security/https/" rel="noreferrer">here</a> to add tls security for docker api. Certificates are located in <strong>~/.docker/</strong> as well as <strong>/etc/docker/ssl/</strong> folders. I added <strong>override.conf</strong> to <strong>/etc/systemd/system/docker.service.d/</strong> with content</p>
  
  <pre><code>[Service]
  ExecStart=
  ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2376 --tlsverify --tlscacert=ca.pem --tlscert=server-cert.pem --tlskey=server-key.pem
  </code></pre>
  
  <p>Then, I used daemon-reload and docker start</p>
  
  <pre><code>$ systemctl daemon-reload
  $ service docker start
  </code></pre>
  
  <p>The errors in <strong>journalctl -xe</strong> is:</p>
  
  <pre><code>-- Unit docker.socket has finished starting up.
  -- 
  -- The start-up result is RESULT.
  Jan 15 21:43:24 cynicalplyaground systemd[1]: docker.service: Start request repeated too quickly.
  Jan 15 21:43:24 cynicalplyaground systemd[1]: docker.service: Failed with result 'exit-code'.
  Jan 15 21:43:24 cynicalplyaground systemd[1]: Failed to start Docker Application Container Engine.
  -- Subject: Unit docker.service has failed
  -- Defined-By: systemd
  -- Support: http://www.ubuntu.com/support
  -- 
  -- Unit docker.service has failed.
  -- 
  -- The result is RESULT.
  Jan 15 21:43:24 cynicalplyaground systemd[1]: docker.socket: Failed with result 'service-start-limit-hit'.
  Jan 15 21:45:01 cynicalplyaground CRON[12768]: pam_unix(cron:session): session opened for user root by (uid=0)
  Jan 15 21:45:01 cynicalplyaground CRON[12769]: (root) CMD (command -v debian-sa1 &gt; /dev/null &amp;&amp; debian-sa1 1 1)
  Jan 15 21:45:01 cynicalplyaground CRON[12768]: pam_unix(cron:session): session closed for user root
  </code></pre>
  
  <p>How can I sort this issue?</p>