first you should add the below proxies to /etc/environment
root@gitlab:~# cat /etc/environment
PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin"
HTTP_PROXY=http://YOUR_PROXY
HTTPS_PROXY=http://YOUR_PROXY
http_proxy=http://YOUR_PROXY
https_proxy=http://YOUR_PROXY
then you better create a virtualenv and use it:
python -m venv ./gitlab
source gitlab/bin/activate
then you should install the requirement.txt
pip install requirement.txt
then you should install the gitlab role
ansible-galaxy install geerlingguy.gitlab
then you should specify the variable like gitlab_domain and other if you want in vars/main.yml then apply the playbook
ansible-playbook -i inventory/hosts.yml --become --become-user=root gitlab.yml