title: How to find what ports are exposed from docker image?
body: <p>I have some docker image. In my example it is called <code>sample_nginx</code>:</p>
  
  <pre><code>$ docker images
  REPOSITORY          TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
  sample_nginx        latest              4b34f8307839        34 hours ago        231.6 MB
  </code></pre>
  
  <p>I can run it <code>docker run sample_nginx</code> and in the colomn "PORTS" I can see what ports are exposed from that image:</p>
  
  <pre><code>$ docker ps -a
  CONTAINER ID        IMAGE                 COMMAND                CREATED             STATUS              PORTS               NAMES
  650d7a9fe46e        sample_nginx:latest   "/bin/sh -c 'nginx -   3 minutes ago       Up 3 minutes        80/tcp              sleepy_mclean
  </code></pre>
  
  <p>Is it possible to find out what ports are exposed from the image without running it?</p>