title: How to access SSH keys for a Google Cloud Platform Compute Engine VM instance?
body: <p>I created a new instance via the Google Cloud web console from a CentOS 6.x image. I saw a blank on the creation form where I could paste in an existing SSH key; since this was my first instance, I didn't have one yet. I assumed it would take me through the key creation process like Amazon EC2 does. It didn't.</p>
  <p>The instance appears to be created, but I can't figure out how to get the SSH key for it. The instance web page has a button that says &quot;SSH&quot; and it let me log in briefly via a pop-up web browser window that simulates an SSH session. However, it only let me into a user-level account, not <code>root</code>. The pop-up had a menu item to change the user and changing it to <code>root</code> does nothing but generate connection errors.  Now I can't log into my instance at all!</p>
  <p>I've searched but can't find any straight-forward documentation that explains this aspect of Google Compute instances.</p>
  <p>Do I have to create my own SSH keys manually and paste them into the form during instance creation?  Is there an obvious step I'm missing?</p>