Expose API/stub_status on a custom port

[isaachawley]

NGINX Plus will listen on a socket, /var/run/nginx-plus-api.sock, so the Ingress Controller can still connect to modify upstream servers when the API is disabled.

Adds command-line arguments:

• -nginx-status to enable/disable status & stub_status
• -nginx-status-port the port

Checklist:

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto master
• I will ensure my PR is targeting the master branch and pulling from my branch from my own fork

[isaachawley]

@r4j4h here's our internal stub-status PR. You can see it doesn't have the status-allow-ip feature that was in yours. I still think that's a good idea, maybe as an array of CIDRs? The nginx allow/deny directives take CIDR notation.

[r4j4h]

Thanks @isaachawley, this looks good. I think supporting multiple CIDRs is a great idea! I am thinking we can accept the array of CIDRs via comma separated list in the status-allow-ip argument. If you guys have better ways to implement in mind I am all ears, but in the meantime I will get started on a new pull request under that direction. 👍

[isaachawley]

That sounds great @r4j4h, Thanks

[pleshakov]

hi @r4j4h
we created an issue where we proposed an implementation for this feature. See #355

Please let us know what you think and if you're ok with following that implementation. We'd be happy to help with the implementation.

[r4j4h]

Hi @isaachawley and @pleshakov , sorry it took me a little while but I have a first stab at #387 if you would like to take a look when you have some time. :)