Image username is ignored on GCE
Description of problem:
When creating an image (in this case on GCE), you can specify a username. Iiuc, this username is then used by Foreman to run the finish_template.
On GCE, this username is completely ignored, so when creating a new instance, the Fog default of 'root' is used to setup ssh public key authentication for. This fails, of course, because root would never be allowed to log in remotely on a cloud instance by default.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Setup GCE compute resource (see bug 1374335)
2. Specify image and setup username
3. Try and create a new host
Running the finish_template fails, so new host is left unconfigured
Workaround is to override the default in line 20 of /opt/theforeman/tfm/root/usr/share/gems/gems/fog-core-1.36.0/lib/fog/compute/models/server.rb, so I'm thinking the username is not passed to the Fog Google::Server class properly.