<p>The first step to creating an image is to create a container and fill it with some data.</p>

<p>First we'll create a container with a single new file based off of the <code>ubuntu</code> base image:</p>

<pre class="command">
<code ng-show="tour.tourScope.showSudo">sudo </code>docker run busybox echo "fun" > newfile
</pre>

<p>The container will immediately terminate (because its one command is <code>echo</code>), so we'll use <code>docker ps -l</code> to list it:

<pre class="command">
<code ng-show="tour.tourScope.showSudo">sudo </code>docker ps -l
CONTAINER ID        IMAGE               COMMAND             CREATED 
<var class="var1">07f2065197ef</var>          ubuntu:12.04        echo fun            31 seconds ago   
</pre>

<div class="alert alert-info">
  <div class="control-group">
    <label class="control-label" for="containerId">Enter the container ID returned:</label>
    <div class="form-inline">
      <input type="text" id="containerId" class="form-control" placeholder="containerId" ng-model="tour.tourScope.containerId">
    </div>
  </div>
</div>