title: Make supervisord log to file and stdout
body: <p>I have a docker container running a ping command. This process is managed by supervisord and this is my config file:</p>
  
  <pre><code>[supervisord]
  nodaemon=true
  
  [program:ping]
  command=ping 1.1.1.1
  autostart=true
  autorestart=true
  redirect_stderr=true
  stdout_logfile=/var/log/ping.out.log
  </code></pre>
  
  <p>The <code>stdout</code> of <code>ping 1.1.1.1</code> is being saved to <code>/var/log/ping.out.log</code> </p>
  
  <p><strong>I'd also like it to be sent to <code>/dev/stdout</code> so I can view the log in my console.</strong> </p>
  
  <p>My hacky way to do this is run a second process to <code>tail -f</code> the log file. So my hacky config file looks like this:</p>
  
  <pre><code>[supervisord]
  nodaemon=true
  
  [program:ping]
  command=ping 1.1.1.1
  autostart=true
  autorestart=true
  redirect_stderr=true
  stdout_logfile=/var/log/ping.out.log
  
  [program:ping-log]
  command=tail -f /var/log/ping.out.log
  stdout_logfile=/dev/stdout
  stdout_logfile_maxbytes=0
  redirect_stderr=true
  </code></pre>
  
  <p><strong>Question is, is this 'hacky' approach ok? Or is there a better way to do this?</strong>
  I want to be able to run <code>docker log &lt;container id&gt;</code> to get my logs</p>