title: HttpRequestException when making http request between Localstack Lambda and docker container
body: <p>I've got two docker containers running as part of a docker-compose file, ContainerA is localstack where I'm running a lambda function which is trying to make a HTTP POST request to ContainerB using the below simplified code:</p>
  <pre><code>var content = new StringContent(&quot;{ &quot;content&quot;: &quot;sample&quot; }&quot;, Encoding.UTF8, &quot;application/json&quot;);
  var httpClient = new HttpClient();
  var response = await HttpClient.PostAsync(&quot;http://ContainerB/Foo&quot;, content);
  </code></pre>
  <p>Which raises the following exception:</p>
  <blockquote>
  <p>Request failed - System.Net.Http.HttpRequestException: Name or service not known</p>
  </blockquote>
  <p>If I make the same request from the console of Container A this request succeeds e.g.</p>
  <p><code>curl http://ContainerB/Foo -H &quot;Content-Type: application/json&quot; -d &quot;{ &quot;content&quot;: &quot;sample&quot; }&quot;</code></p>
  <p>As this request succeeds from the console I'm fairly confident that it's not a networking issue between my docker containers.</p>