Need to fix 502 Bad Gateway linux server

Job ID: 36768612

Budget: $10 – $30 AUD

I have installed gitlab from turnkeylinux (debian)
Now I am facing too problem
1)after restart of server gitlab page is not opening giving me this error
502 Bad Gateway
openresty
I guess small configuration might cause this problem

when I am trying to push 2.1 GB of data in a single push it gives me error

I needed from an expert
Related categories: PHP System Admin Linux Apache Debian