feat(nginx): add optional environment variable to override NGINX default listen port

[nikAizuddin]

Hi, I would like to add optional environment variable NGINX_HTTP_PORT to override NGINX default HTTP listen port.

I can't find other ways to change Saferwall UI's listen port, so I guess this is the only way?

[ayoubfaouzi]

LGTM. Btw Nik, why would you need that ? you can always map the host port of your choice to the container port.

[nikAizuddin]

Usually I may have 2 use cases during deployment, for example:

1. Need to use network=host to preserve client's IP address in NGINX logs. If using port mapping, the client's IP becomes the container's gateway network IP. For example:

NGINX logs when using network=host:

192.168.1.11 - - [11/Feb/2022:09:00:15 +0000] "GET // HTTP/2.0" 200 615 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:97.0) Gecko/20100101 Firefox/97.0"

NGINX logs when using port mapping:

10.0.2.100 - - [11/Feb/2022:09:03:30 +0000] "GET // HTTP/2.0" 304 0 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:97.0) Gecko/20100101 Firefox/97.0"

2. Prevent port conflict within a pod. For example if I create a pod and then include both Saferwall UI container and my own NGINX container, I can't make my NGINX listen to port 80.

[ayoubfaouzi]

Thanks a lot @nikAizuddin, seems both valid uses cases. Thanks for your contribution !