title: Docker Container Version Control
body: <p>Does anyone know of a good way to check the version of tools inside of Docker containers? Currently I am sshing into each container and checking the version. Ideally we would like to somehow expose the versions of our tools so we can just call the container with PHP – version and it tells us its version.</p>
  <p>We are trying to make sure all of our different environments ( and local) have containers which share the same versions of our tools. In the past it has been an issue where locally we might be developing in PHP 5.5 but our production docker had PHP 5.4</p>
  <p>Currently I am trying to set up a system that runs nightly and will slack our dev team if the versions of tools are different, but that requires sshing into each container.</p>
  <p>Any better ideas to check versions of tools?</p>