traefik/docs/content/middlewares/stripprefix.md

StripPrefix

Removing Prefixes From the Path Before Forwarding the Request {: .subtitle }

Remove the specified prefixes from the URL path.

Configuration Examples

# Strip prefix /foobar and /fiibar
labels:
  - "traefik.http.middlewares.test-stripprefix.stripprefix.prefixes=/foobar,/fiibar"

# Strip prefix /foobar and /fiibar
apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: test-stripprefix
spec:
  stripPrefix:
    prefixes:
      - /foobar
      - /fiibar

# Strip prefix /foobar and /fiibar
- "traefik.http.middlewares.test-stripprefix.stripprefix.prefixes=/foobar,/fiibar"

"labels": {
  "traefik.http.middlewares.test-stripprefix.stripprefix.prefixes": "/foobar,/fiibar"
}

# Strip prefix /foobar and /fiibar
labels:
  - "traefik.http.middlewares.test-stripprefix.stripprefix.prefixes=/foobar,/fiibar"

# Strip prefix /foobar and /fiibar
[http.middlewares]
  [http.middlewares.test-stripprefix.stripPrefix]
    prefixes = ["/foobar", "/fiibar"]

# Strip prefix /foobar and /fiibar
http:
  middlewares:
    test-stripprefix:
      stripPrefix:
        prefixes:
          - "/foobar"
          - "/fiibar"

Configuration Options

General

The StripPrefix middleware will:

• strip the matching path prefix.
• store the matching path prefix in a X-Forwarded-Prefix header.

!!! tip

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

prefixes

The prefixes option defines the prefixes to strip from the request URL.

For instance, /products would match /products but also /products/shoes and /products/shirts.

Since the path is stripped prior to forwarding, your backend is expected to listen on /.

If your backend is serving assets (e.g., images or Javascript files), chances are it must return properly constructed relative URLs.
Continuing on the 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).

The X-Forwarded-Prefix header can be queried to build such URLs dynamically.

forceSlash

Optional, Default=true

labels:
  - "traefik.http.middlewares.example.stripprefix.prefixes=/foobar"
  - "traefik.http.middlewares.example.stripprefix.forceSlash=false"

apiVersion: traefik.containo.us/v1alpha1
kind: Middleware
metadata:
  name: example
spec:
  stripPrefix:
    prefixes:
      - "/foobar"
    forceSlash: false

"labels": {
  "traefik.http.middlewares.example.stripprefix.prefixes": "/foobar",
  "traefik.http.middlewares.example.stripprefix.forceSlash": "false"
}

labels:
  - "traefik.http.middlewares.example.stripprefix.prefixes=/foobar"
  - "traefik.http.middlewares.example.stripprefix.forceSlash=false"

[http.middlewares]
  [http.middlewares.example.stripPrefix]
    prefixes = ["/foobar"]
    forceSlash = false

http:
  middlewares:
    example:
      stripPrefix:
        prefixes:
          - "/foobar"
        forceSlash: false

The forceSlash option makes sure that the resulting stripped path is not the empty string, by replacing it with / when necessary.

This option was added to keep the initial (non-intuitive) behavior of this middleware, in order to avoid introducing a breaking change.

It's recommended to explicitly set forceSlash to false.

??? info "Behavior examples"

- `forceSlash=true`

| Path       | Prefix to strip | Result |
|------------|-----------------|--------|
| `/`        | `/`             | `/`    |
| `/foo`     | `/foo`          | `/`    |
| `/foo/`    | `/foo`          | `/`    |
| `/foo/`    | `/foo/`         | `/`    |
| `/bar`     | `/foo`          | `/bar` |
| `/foo/bar` | `/foo`          | `/bar` |

- `forceSlash=false`

| Path       | Prefix to strip | Result |
|------------|-----------------|--------|
| `/`        | `/`             | empty  |
| `/foo`     | `/foo`          | empty  |
| `/foo/`    | `/foo`          | `/`    |
| `/foo/`    | `/foo/`         | empty  |
| `/bar`     | `/foo`          | `/bar` |
| `/foo/bar` | `/foo`          | `/bar` |