Correct way of setting specific SSH connection options to GCE plugin

[iamroddo]

I want to set the SSH private key that Molecule GCE plugin uses.

Even though at https://github.com/ansible-community/molecule-gce/blob/main/src/molecule_gce/driver.py#L36 states "This driver assumes the developer has deployed project wide ssh key". However at https://github.com/ansible-community/molecule-gce/blob/main/src/molecule_gce/playbooks/tasks/create_linux_instance.yml#L2 a new SSH key is created and written to "{{ lookup('env', 'MOLECULE_EPHEMERAL_DIRECTORY') }}/ssh_key".

How can I provide the path to the SSH private key and username that Molecule should use?

If I add something like the following to molecule.yml, then run molecule create && molecule converge , SSH authentication using the provided keyfile works. However with molecule test, SSH authentication fails at the converge stage with an error that shows that the correct

Also when I execute molecule login I'm presented with a password prompt for the wrong user ('root' the user in the terminal where 'molecule' is executed.).

I have added that below to molecule.yml.

provisioner:
  connection_options:
    ansible_ssh_common_args: '-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null'
    ansible_private_key_file: /root/.ssh/jenkins_private_key
    ansible_user: jenkins

In instance_config.yml in ~/.cache/molecule/<role name>/<scenario name>, "user" is "root" and "identity_file" is "/root/.cache/molecule/groups/default/ssh_key" rather than the desired one "/root/.ssh/jenkins_private_key". If replace manually the values of "user" & "identity_file" to my custom ones, molecule login works.

I see that the file instance_config.yml is created by a handler in GCE plugin with the value of "user" being that of the env var USER and "identity_file" being "{{ lookup('env', 'MOLECULE_EPHEMERAL_DIRECTORY') }}/ssh_key". How can I influence these values while using the GCE driver?