Automate SSH key pair creation/generation for another user - ssh

Question

i am trying to automate the process to order a linux instance and also handle the ssh keys on the instance-level.
Is it possible to generate a ssh key file for another user with the gcloud command line (without ssh'ing to it, that auto generate keys).
For Windows instances it looks like this:
I automate the instance creation
I automate generating windows password for windows instances
I email the newly generated password to the requesting user
For Linux:
I have automated linux instance creation
But what do i do next to generate a ssh key for another specific username so that i can attach in the email to the requesting user. The user does not have access to the GCE dashboard.
With AWS its simple because then i create the keys before the instance and can attach those, but dont know how to solve this automation issue with GCE.
Help?!
Thanks

Answer 1

Take a look at the instructions for "Adding and Removing SSH Keys", summarized here:
$ # Creating a new SSH key-pair with the correct format (`USERNAME` is your Google username
$ ssh-keygen -t rsa -f ~/.ssh/[KEY_FILE_NAME] -C [USERNAME]
$ # Edit the file. It should look like the following line:
$ # [USERNAME]:ssh-rsa [KEY_VALUE] [USERNAME]
$ vim ~/.ssh/[KEY_FILE_NAME]
$ # Get the existing metadata for the instance:
$ gcloud compute instances describe [INSTANCE]
$ # Look for the "metadata" -> "ssh-keys" entry and merge your new SSH key in.
$ vim all_keys.txt # This is where the merged key list goes
$ gcloud compute instances add-metadata [INSTANCE_NAME] \
--metadata-from-file ssh-keys=all_keys.txt
The link contains advanced instructions for adding an expiration time, adding the key to the entire project, blocking project-wide keys from working on an instance, using the Cloud Console instead of gcloud, doing this on Windows, etc.
That said, I'd urge you to use caution when emailing SSH private keys around.