Configure HTTPS for gitlab with self hosted certificate

Hi everyone,

I have currently configured gitlab in a private server (without DNS) in a docker container. I would like to activate the SSL encryption, I have read the documentation and followed many tutorial but I cannot get it running correcty.

I have create the self-signed certificate using this:
Generating a Self-Signed Certificate

and this is how my gitlab.rb looks like into my docker container:

external_url 'https://{local server ip address}:8080'
nginx['enable'] = true
nginx['redirect_http_to_https'] = true
nginx['ssl_certificate'] = "/etc/gitlab/ssl/my_certificate.crt"
nginx['ssl_certificate_key'] = "/etc/gitlab/ssl/my_certificate.key"
letsencrypt['enable'] = false
letsencrypt['auto_renew'] = false

can you please indicate me what I am doing wrong? After the reconfigure and the restart I cannot reach anymore my instance either using http or https.