I am setting up a server by following the directions here:

Initial set up of Ubuntu 20.04 server: https://www.digitalocean.com/community/tutorials/initial-server-setup-with-ubuntu-20-04

Installing Nginx: https://www.digitalocean.com/community/tutorials/how-to-install-nginx-on-ubuntu-20-04

Securing Nginx: https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-20-04

I’ve followed everything step-by-step and my server works on HTTPS. However when I try to clone a git repo hosted on GitLab, the connection repeatedly fails with the following error:

kex_exchange_identification: Connection closed by remote host
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

Now, I have generated an SSH key on my server (via ssh-keygen) and added the public SSH key to the Gitlab website.

However the firewall is not allowing me to connect. I have tried “sudo ufw allow git” but this did not work.

I was able to clone the repo by disabling the firewall (sudo ufw disable) and then enabling the firewall after the repo has been cloned, however this is not a realistic solution for obvious reasons.

Can anyone help out? Do I allow a certain port or specific IP for Gitlab connections?

Thanks