rewrite-path

Reshapes the path when removing or adding a prefix is not enough - reordering segments, dropping one in the middle, folding two shapes into one.

Parameters

Name	Type	Required	What it does
`pattern`	string	yes	The regexp matched against the path.
`replacement`	string	yes	What replaces it. Captures are `$1`, `$2`.

A pattern that does not compile is refused when the route is saved.

Example

filters:
  - type: rewrite-path
    args:
      pattern: ^/shop/v2/(.*)$
      replacement: /api/$1

/shop/v2/orders/8814 reaches the service as /api/orders/8814.

Notes

Anchor the pattern with ^ unless you mean to match anywhere: an unanchored pattern rewrites every occurrence in the path, which is rarely what was meant.

A capture written $1 followed by a letter reads as the group named 1x, which does not exist, and the replacement silently loses it. Write ${1} whenever a letter or a digit follows.

The regexp syntax is Go's RE2: no backreferences and no lookaround. A pattern borrowed from another gateway may need rewriting.

For the two everyday cases there are simpler bricks: strip-prefix and prefix-path. Unlike strip-prefix, this filter announces nothing: a service that builds its own links will not know it lives under a prefix.