How can I add a GCE user and let him connect in the web-browser SSH?

Question

I would like to add a Google user on the Compute Engine project and give him a SSH (root and non-root) access from the web-browser on my Debian 9 VM.

I already invited and set the 'Compute Engine Administrator' role on the user, but it still doesn't work. When he tries to connect, he have an error like "keys transfer to metadata of the project is particularly long, you can transfer them to the instance metadata to gain time, ..."

Answer 1

This article shows how to grant Cloud IAM roles to project members using the Google Cloud Platform Console.

And this document shows how to just give a user the ability to connect to a virtual machine instance using SSH, but don't want to grant them the ability to manage Compute Engine resources, add the user's public key to the project, or add a user's public key to a specific instance.

Also, in order to SSH using root as a user you need to create SSH key pair first. You can create key pair manually and update the public key in project/instance metadata which will than be propagated to the VM instance.