title: Docker build timestamps
body: <p>Is it possible to get step timestamps in a console/log file while running docker build command?</p>
  
  <pre class="lang-sh prettyprint-override"><code>Step 28/49 : RUN find dist -name "*.map" -delete 
   ---&gt; Running in 5e1ee1063999 
  Removing intermediate container 5e1ee1063999 
   ---&gt; a02191df133c 
  Step 29/49 : FROM dotnet-install AS web-build 
   ---&gt; e0ecdc23b275 
  Step 30/49 : COPY src src 
   ---&gt; d33c7da41fb9
  </code></pre>
  
  <p>I would like to identify the slowest steps and I would expect something like:</p>
  
  <pre class="lang-sh prettyprint-override"><code>2019-11-25T12:00:00Z : Step 28/49 : RUN find dist -name "*.map" -delete 
   ---&gt; Running in 5e1ee1063999 
  Removing intermediate container 5e1ee1063999 
   ---&gt; a02191df133c 
  2019-11-25T12:10:00Z : Step 29/49 : FROM dotnet-install AS web-build 
   ---&gt; e0ecdc23b275 
  2019-11-25T12:20:00Z : Step 30/49 : COPY src src 
   ---&gt; d33c7da41fb9
  </code></pre>