title: AWS App Runner start command with quoted whitespaces
body: <p>I'm creating an <a href="https://aws.amazon.com/apprunner/" rel="nofollow noreferrer">AppRunner</a> service from a private ECR image with a Start command:</p>
  <pre><code>--before 'echo $MYVAR &gt; /tmp/log.txt'
  </code></pre>
  <p>Which should be passed as is into my container entrypoint.</p>
  <p>However, in App Runner application logs I get an error:</p>
  <pre><code>Couldn't find match for argument PARSE ERROR: Argument: $MYVAR
  </code></pre>
  <p>If I run the image using just Docker the whole  <code>'echo $MYVAR &gt; /tmp/log.txt'</code> is interpreted as one argument to <code>--before</code>.</p>
  <p>But in the App Runner two arguments are passed to the entrypoint:</p>
  <ul>
  <li><code>--before</code> with <code>'echo</code> value</li>
  <li><code>$MYVAR &gt; /tmp/log.txt'</code></li>
  </ul>
  <p>Second argument cases a parsing error in the entrypoint since it's invalid.</p>
  <p>I have tried various ways of specifying an entrypoint but they all fail:</p>
  <pre><code>--before &quot;echo $MYVAR &gt; /tmp/log.txt&quot;
  --before \'echo $MYVAR &gt; /tmp/log.txt\'
  
  </code></pre>
  <p>Is there any way I can pass <code>'echo $MYVAR &gt; /tmp/log.txt'</code> ass one argument to <code>--before</code> in App Runner start command?</p>