Situation: In web development I need to be logged into an application as an administrator, normal user, unauthenticated user etc. I'd like to have a set up where each browser window is unaware of the other's logged in session.

Question: How can I have multiple browser windows open but have them running from different profiles or different cache areas? If firefox profiles, how can I achieve this without using the Profile editor UI?

Can I create a temporary user, run Firefox, then just throw away the entirety of that user account? Or, should I be using like a browser-in-a-VM?

What I've tried so far:

Bash

My first attempt was to try something like the following:

# create temp user
tmp_user=`head -c 10 /dev/random | base64 | head -c 10`

# create user
sudo useradd $tmp_user;

# run browser
sudo -u $tmp_user `which firefox`

# hold and wait then kill account
sudo userdel $tmp_user

I got so far as sudo -u $tmp_user firefox the following error displayed:

sh: 0: getcwd() failed: No such file or directory

sh: 0: getcwd() failed: No such file or directory

No protocol specified

Failed to connect to Mir: Failed to connect to server socket: No such file or directory Unable to init server: Could not connect: Connection refused Error: cannot open display: :0

Firejail

I then tried firejail, however, I think I misunderstood what this prgoram was meant to do. The main firefox window and one started under firejail firefox was aware of each others login sessions.