Error 502 with GitLab installation on Ubuntu 16.04

Hi, I’ve tried to search for and go through relevant discussions but still had no luck troubleshooting the problem on my own. Please help.
I followed omnibus package installation instructions to install GitLab on an internal Ubuntu computer given as its IP address on the local network and the router has also been set up so if the browser is pointed to it’ll be routed to

In such an environment, what URL (including the port #) should be provided as the external URL in GitLab installation?
Besides, Apache has already been up and running on the said internal Ubuntu computer. Do I have to follow the steps at to use Apache instead? Is it okay to use NGINX coming with GitLab by default while there is already Apache up and running?
What else should be configured in particular to make it work?

(As to the firewall, here is what’s returned from running sudo ufw status on the CLI – Status: inactive.)

Any advice is greatly appreciated. Thanks.

Sad that I got no help here, so I spent lots of time searching the Web for a solution. Quite some people posted how they had got GitLab up and running on their own. I followed suit but still had no luck working it out until I acted on this post on stack overflow in addition to NGINX settings | GitLab, plus uncommenting:

unicorn['listen'] = ''
unicorn['port'] = 9418

in /etc/gitlab/gitlab.rb.
Finally I got something visible as follows after entering http://localhost:9418 or http://gitlab.localhost in the browser, though it still seemed abnormal.

Can anyone help me out, please?

I have the same issue. Or at least similar. Have you been able to find anything useful? I need my pages accessible from outside of the company network.