I'm trying to create rewrite rules for nginx ingress for directing the following URLs to the same service:

example/ws?list=a,b,c

example/ws/?list=a,b,c

Pasting in the regexps bellow from my helm chart in the context with the other rules that need to work.

So basically my question is: How to I write a nginx compatible regexp that contains a questionmark?

I thought this would solve it:

- path: /api/(.*)  <----- THIS IS FOR ANOTHER SERVICE
  pathType: ImplementationSpecific
  component: "{{ .Values.backendponent }}"
  port: "{{ .Values.backend.service.port }}"
- path: /ws/(.*) <------- WORKS
  pathType: ImplementationSpecific
  component: "{{ .Values.broadcasterponent }}"
  port: "{{ .Values.broadcaster.service.port }}"
- path: /ws(\?.*) <-------- NOT WORKING
  pathType: ImplementationSpecific
  component: "{{ .Values.broadcasterponent }}"
  port: "{{ .Values.broadcaster.service.port }}"
- path: /(.*)
  pathType: ImplementationSpecific
  component: "{{ .Values.frontendponent }}"
  port: "{{ .Values.frontend.service.port }}"

I'm trying to create rewrite rules for nginx ingress for directing the following URLs to the same service:

example.com/ws?list=a,b,c

example.com/ws/?list=a,b,c

Pasting in the regexps bellow from my helm chart in the context with the other rules that need to work.

So basically my question is: How to I write a nginx compatible regexp that contains a questionmark?

I thought this would solve it:

- path: /api/(.*)  <----- THIS IS FOR ANOTHER SERVICE
  pathType: ImplementationSpecific
  component: "{{ .Values.backend.component }}"
  port: "{{ .Values.backend.service.port }}"
- path: /ws/(.*) <------- WORKS
  pathType: ImplementationSpecific
  component: "{{ .Values.broadcaster.component }}"
  port: "{{ .Values.broadcaster.service.port }}"
- path: /ws(\?.*) <-------- NOT WORKING
  pathType: ImplementationSpecific
  component: "{{ .Values.broadcaster.component }}"
  port: "{{ .Values.broadcaster.service.port }}"
- path: /(.*)
  pathType: ImplementationSpecific
  component: "{{ .Values.frontend.component }}"
  port: "{{ .Values.frontend.service.port }}"

• kubernetes
• nginx
• nginx-ingress

1 Answer 1

The question mark in the URL is part of the query string and not the path but however you can use the * modifier in regex to make the ? optional. Since the query string (anything starting with?) is not a part of the normalised URI, you cannot match it in location and rewrite expressions. Refer to official document on Module ngx_http_core_module for more details.

You could test for the presence of a query string then use rewrite to remove them:

if ($args) {
    rewrite ^/$ /? permanent;
}

And also If you have a number of URIs to redirect, you should consider using a map.To process many URIs, use a map directive, for example:

map $request_uri $redirect {
    default 0;
    /somepath/somearticle.html?p1=v1&p2=v2  /some-other-path-a;
    /somepath/somearticle.html              /some-other-path-b;
}

server {
    ...
    if ($redirect) {
        return 301 $redirect;
    }
    ...
}

Note: You can also use regular expressions in the map, for example, if the URIs also contain optional unmatched parameters. See this official Nginx document for more info.