title: How does Docker name repositories?
body: <p>In a directory called <code>ringer</code> i've created a simple Dockerfile that will install some stuff and mount my app... I have never explicitly set a name.</p>
  
  <p>I then used a <code>docker-compose.yml</code> file to define <code>web</code> and pointed it at the <code>Dockerfile</code> i mentioned above.</p>
  
  <p>When i run <code>docker images</code> i see the following: </p>
  
  <pre><code>$ docker images
  REPOSITORY                     TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
  ringer_web                     latest              bf9b931e1030        8 minutes ago       938.9 MB
  </code></pre>
  
  <p>It looks like Docker named my image's repository after the local directory and image name... My question is, how exactly does Docker choose to name an image's repository? (and if applicable, why) </p>