title: What does the "." in "docker run <image> . " do?
body: <p>I have 2 commands:</p>
  <p><code>docker run -d -p 5000:8080 ${image_name} .</code></p>
  <p>and</p>
  <p><code>docker run -d -p 5000:8080 ${image_name}</code></p>
  <p>The only difference between these two commands is the period at the end. What is the purpose of the period? I understand that it signifies the current directory, but what is its use in a command like this?</p>