traefik/docs/content/middlewares/stripprefixregex.md

StripPrefixRegex

Removing Prefixes From the Path Before Forwarding the Request (Using a Regex) {: .subtitle }

Remove the matching prefixes from the URL path.

Configuration Examples

labels:
  - "traefik.http.middlewares.test-stripprefixregex.stripprefixregex.regex=/foo/[a-z0-9]+/[0-9]+/"

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: test-stripprefixregex
spec:
  stripPrefixRegex:
    regex:
      - "/foo/[a-z0-9]+/[0-9]+/"

- "traefik.http.middlewares.test-stripprefixregex.stripprefixregex.regex=/foo/[a-z0-9]+/[0-9]+/"

"labels": {
  "traefik.http.middlewares.test-stripprefixregex.stripprefixregex.regex": "/foo/[a-z0-9]+/[0-9]+/"
}

labels:
  - "traefik.http.middlewares.test-stripprefixregex.stripprefixregex.regex=/foo/[a-z0-9]+/[0-9]+/"

[http.middlewares]
  [http.middlewares.test-stripprefixregex.stripPrefixRegex]
    regex = ["/foo/[a-z0-9]+/[0-9]+/"]

http:
  middlewares:
    test-stripprefixregex:
      stripPrefixRegex:
        regex:
          - "/foo/[a-z0-9]+/[0-9]+/"

Configuration Options

General

The StripPrefixRegex middleware strips the matching path prefix and stores it in a X-Forwarded-Prefix header.

!!! tip

Use a `stripPrefixRegex` middleware if your backend listens on the root path (`/`) but should be exposed on a specific prefix.

regex

The regex option is the regular expression to match the path prefix from the request URL.

!!! tip

Regular expressions can be tested using online tools such as [Go Playground](https://play.golang.org/p/mWU9p-wk2ru) or the [Regex101](https://regex101.com/r/58sIgx/2).

For instance, /products also matches /products/shoes and /products/shirts.

If your backend is serving assets (e.g., images or JavaScript files), it can use the X-Forwarded-Prefix header to properly construct relative URLs. Using the previous example, the backend should return /products/shoes/image.png (and not /images.png, which Traefik would likely not be able to associate with the same backend).