title: How to get the output from docker run -i
body: <p><code>docker run</code> normally returns the output of the command it runs. I need to pass some data to docker, run a command that processes the data, and return the output. When I use the <code>-i</code> option, no output is returned. Consider this simple example:</p>
  
  <pre><code>echo hello | docker run -i base wc
  </code></pre>
  
  <p>It returns no output. How can I get the output from docker when using the <code>-i</code> option?</p>