title: How to iterate through all the ENV variables printing key and value?
body: <p>I'd like to iterate through the variables in <a href="http://ss64.com/bash/env.html" rel="noreferrer"><code>env</code></a> printing:</p>
  
  <pre><code>name: ${name} value: ${value}
  </code></pre>
  
  <p>Simply splitting by line break and iterating does not work, because of multi-line values, e.g.</p>
  
  <pre><code>SERVER_TLS_SERVER_CRT=-----BEGIN CERTIFICATE-----
  foo
  -----END CERTIFICATE-----
  </code></pre>
  
  <p>The use case is to workaround <a href="https://github.com/docker/docker/issues/12997" rel="noreferrer">Docker limitation</a> that restricts passing multi-line variables via <code>--env-file</code>.</p>