After installation, modify the hostname with (adjust the hostname accordingly):

sudo hostnamectl set-hostname foo999linux.ad.foobar.com

Then reboot.

Note: this should be performed exclusively by IT, since it requires Domain Join rights. Therefore, if regular users attempt to run it, it will probably fail.

Set up your AD variables via ansible/roles/ad/vars/main.yml.

Prepare the workstation to join the domain:

sudo ansible-playbook ansible/ad.yml

Test if the workstation can discover AD properly:

realm discover

If yes, you can join the domain with:

sudo realm join --user <user.name>

If not, it may be laggy network, imperfect drivers, disabled promiscuous mode in virtualization etc. Try joining explicitly, i.e. sudo realm join ad.foobar.com.

If login fails for certain users, try leaving the domain, clearing the SSSD cache, then joining again:

sudo realm leave
sudo systemctl stop sssd
sudo find /var/lib/sss/ -name '*.ldb' -delete
sudo systemctl stop realmd
sudo realm join
sudo reboot