title: How to deploy one app engine app to multiple projects
body: <p>My problem is that I want to create <code>dev</code>, <code>stage</code>, <code>prod</code> environments by using different GCP projects. </p>
  
  <p>Basically they are running the same code, just running them in different isolated environments. </p>
  
  <p>I'm using <code>gcloud app deploy</code> in command line to deploy app right now.</p>
  
  <p>How can I efficiently deploy an app to different project?<br>
  Do I have to do <code>gcloud init</code> to change my configuration of default project every time?<br>
  There must be some better practices. </p>
  
  <p>Or, is there a better way for me to set up <code>dev</code>... environments in the context of app engine?</p>
  
  <p>Thanks.</p>