Host+Path+Regex integrated redirect rule

[alvaro-qwantec]

Is your feature request related to a problem?
Yes, recently I started to use "kube-ingress-aws-controller" in my cluster k8s. A while ago I was using a Nginx server and I used the next redirect rule with success:

server {
    listen 80;
    listen 443 http2 ssl;
    server_name ~^(?<subdomain>\w+)\.example\.com$;
    location / {
        return 301 https://example.com/app/$subdomain;
    }
}

Is like a combination between modRequestHeader with modPath and Regex, and involves the entire request URL.

My question is, How can I do the same thing with Skipper annotations in my Ingress yaml?

Describe the solution you would like
option A) with an environment or context variable and using modRequestHeader and modPath:
modRequestHeader("Host", "^(?<company_id>\w+).example.com$", "example.com") -> modPath("/", "/app/$company_id")

option B) with an environment or context variable and using modRequestHeader and redirectTo:
modRequestHeader("Host", "^(?<company_id>\w+).example.com$", "example.com") -> redirectTo(301, "/app/$company_id")

option C) with a new function like modURL:
modURL("^(?<company_id>\w+).example.com$", "example.com/app/$company_id")

Describe alternatives you've considered (optional)
I don't have others, only the three that I wrote before.

Additional context (optional)
Nothing more.

Would you like to work on it?
No

[szuecs]

Thanks for the idea and options provided, I think it's a valid enhancement request.
We will likely need some time to do it.
There are some more use cases for templating with variables, it's great to have some use cases provided.

Somehow also related to #1444
Cc @AlexanderYastrebov

[AlexanderYastrebov]

It is possible with lua scripting:

all: Host(/^\w+\.example\.com$/) 
-> lua("
function request(ctx, params)
    local subdomain = ctx.request.host:gsub('%.example%.com', '')
    ctx.serve({
        status_code=301,
        header={
            location='https://example.com/app/' .. subdomain,
        },
    })
end
") -> <shunt>;