title: Differences between Sidecar and Ambassador and Adapter pattern
body: <p>I confused between Multi-Container Pod Design patterns.<br>
  (sidecar, adapter, ambassador)  </p>
  
  <p>What I understand is :<br>
  <strong>Sidecar</strong> : container + container(share same resource and do other functions)<br>
  <strong>Adapter</strong> : container + adapter(for checking other container's status. <em>e.g. monitoring</em>)<br>
  <strong>Ambassador</strong> : container + proxy(to networking outside)  </p>
  
  <blockquote>
    <p>But, According to <a href="https://istio.io/docs/setup/additional-setup/sidecar-injection/#injection" rel="noreferrer">Istio -Installing the Sidecar</a>, They introduce proxy as a sidecar pattern. </p>
  </blockquote>
  
  <p>Adapter is container, and Proxy is container too.  </p>
  
  <p>So, My question is <strong>What is differences between Sidecar pattern and Adapter&amp;Ambassador pattern?</strong>  </p>
  
  <p>Is the Sidecar pattern concept contain Adapter&amp;Ambassador pattern?</p>