Confusing of HTTPPathModifier

[hzxuzhonghu]

gateway-api/apis/v1alpha2/httproute_types.go

Lines 719 to 733 in c7da26b

	type HTTPPathModifier struct {
	// Type defines the type of path modifier.
	//
	// <gateway:experimental>
	// +kubebuilder:validation:Enum=Absolute;ReplacePrefixMatch
	Type HTTPPathModifierType `json:"type"`
	// Substitution defines the HTTP path value to substitute. An empty value
	// ("") indicates that the portion of the path to be changed should be
	// removed from the resulting path. For example, a request to "/foo/bar"
	// with a prefix match of "/foo" would be modified to "/bar".
	//
	// <gateway:experimental>
	// +kubebuilder:validation:MaxLength=1024
	Substitution string `json:"substitution"`

How could i rewrite url like /foo/bar prefixed with foo to /bar , it does not allow setting match value

[robscott]

Thanks for the question @hzxuzhonghu! I think #1124 and #1162 will help make this a bit clearer. The value that is being replaced is from the path match. So if you want to use a prefix match to rewrite requests starting with /foo/bar to /bar, you could use config like this:

apiVersion: gateway.networking.k8s.io/v1alpha2
kind: HTTPRoute
metadata:
  name: http-filter-rewrite
spec:
  rules:
    - matches:
      - path:
          type: PathPrefix
          value: /foo/bar
      filters:
      - type: URLRewrite
         urlRewrite:
           path:
             type: ReplacePathPrefix
             replacePathPrefix: /bar
      backendRefs:
      - name: example-svc
        weight: 1
        port: 80

[hzxuzhonghu]

So what will happen if no path match is specified? Because they are two different structs, and so how can you make users understand this well.

[robscott]

Good question. That would be an invalid configuration. We should probably add some webhook validation to prevent that from happening.

[robscott]

x-ref #1166