Log into Google Cloud VM with as specific user using IAM

Question

I created a VM with an Ubuntu 22.04 image and I log in using IAM credentials, not SSH keys, for example:

gcloud beta compute ssh --zone myzone vmname --project myproj --tunnel-through-iap

My command prompt has the username I want.

I just created another VM and it is using my default username ariel_balter_gmail_com.

I have no idea what I did with the first VM to make my username the one I want.

On the first machine, I see:

(base) balter@???????:~$ ls /home
balter  ubuntu

and

(base) balter@????????:~$ cat /etc/passwd | grep balter
balter:x:1001:1002::/home/balter:/bin/bash

On the second machine I created a user "balter", and I see:

(base) ariel_balter_gmail_com@???????:~$ ls /home
ariel_balter_gmail_com  balter

(base) ariel_balter_gmail_com@??????:~$ cat /etc/passwd | grep balter
balter:x:1000:1001:,,,:/home/balter:/bin/bash

I did something different, and I have no idea what.

Answer 1

A Google Cloud IAM identity does not have the same format as a typical SSH Linux identity. Therefore separate home directories are created.

Your Linux machine has two users setup: balter and ariel_balter_gmail_com. The first was probably created as a Linux user for SSH and the other by Google Cloud. They are different identities as far a Linux is concerned.

You also cannot control the user identity string that IAM uses. It is created from the IAM email address.