Expose route for context (#1128)

* Expose route for context

* Update documantation

* Use a protocol-independent route

docs/07.Reference/7.02.Filters.md

@@ -1392,7 +1392,7 @@ Commmon Use-Cases:
 
 1. Replace Prefix:
 
-Substitute a prefix with `/account` and return a `302 Found` status code.
+Substitute a prefix with `/account` and return a `302 Found` status code. The prefix was decided in `pathPrefix` in te matchting rule in HTTPServer.
 
 ```yaml
 name: demo-pipeline
@@ -1402,7 +1402,6 @@ flow:
 filters:
 - name: redirectorv2
  kind: RedirectorV2
- pathPrefix: /user
  path:
  type: ReplacePrefixMatch
  replacePrefixMatch: /account
@@ -1441,7 +1440,6 @@ filters:
  kind: RedirectorV2
  scheme: https
  hostname: newdomain.com
- pathPrefix: /user
  path:
  type: ReplacePrefixMatch
  replacePrefixMatch: /account

pkg/context/context.go

@@ -73,6 +73,7 @@ type Context struct {
 
  activeNs string
 
+ route protocols.Route
  requests map[string]*requestRef
  responses map[string]*responseRef
 
@@ -92,6 +93,20 @@ func New(span *tracing.Span) *Context {
  return ctx
 }
 
+// SetRoute sets the route.
+func (ctx *Context) SetRoute(route protocols.Route) {
+ ctx.route = route
+}
+
+// GetRoute returns the route with the existing flag.
+func (ctx *Context) GetRoute() (protocols.Route, bool) {
+ if ctx.route == nil {
+ return nil, false
+ }
+
+ return ctx.route, true
+}
+
 // Span returns the span of this Context.
 func (ctx *Context) Span() *tracing.Span {
  return ctx.span

pkg/filters/redirectorv2/redirectorv2.go

@@ -25,6 +25,7 @@ import (
 
  "github.com/megaease/easegress/v2/pkg/context"
  "github.com/megaease/easegress/v2/pkg/filters"
+ httprouters "github.com/megaease/easegress/v2/pkg/object/httpserver/routers"
  "github.com/megaease/easegress/v2/pkg/protocols/httpprot"
 
  gwapis "sigs.k8s.io/gateway-api/apis/v1"
@@ -76,7 +77,6 @@ type (
  Spec struct {
  filters.BaseSpec `json:",inline"`
 
- PathPrefix *string `json:"pathPrefix,omitempty"`
  gwapis.HTTPRequestRedirectFilter `json:",inline"`
  }
 )
@@ -108,10 +108,6 @@ func (s *Spec) Validate() error {
  return errors.New("invalid path of Redirector, replaceFullPath can't be empty")
  }
  case gwapis.PrefixMatchHTTPPathModifier:
- if s.PathPrefix == nil || *s.PathPrefix == "" {
- return errors.New("invalid path of Redirector, pathPrefix can't be empty")
- }
-
  if s.Path.ReplacePrefixMatch == nil {
  return errors.New("invalid path of Redirector, replacePrefixMatch can't be empty")
  }
@@ -178,8 +174,25 @@ func (r *Redirector) Handle(ctx *context.Context) string {
  case gwapis.FullPathHTTPPathModifier:
  redirectURL.Path = string(*r.spec.Path.ReplaceFullPath)
  case gwapis.PrefixMatchHTTPPathModifier:
+ route, existed := ctx.GetRoute()
+ if !existed {
+ ctx.AddTag("route not found")
+ break
+ }
+
+ if route.Protocol() != "http" {
+ ctx.AddTag("route is not an http route")
+ break
+ }
+
+ prefix := route.(httprouters.Route).GetPathPrefix()
+ if prefix == "" {
+ ctx.AddTag("route has no path prefix")
+ break
+ }
+
  redirectURL.Path = r.subPrefix(redirectURL.Path,
- *r.spec.PathPrefix, string(*r.spec.Path.ReplacePrefixMatch))
+ prefix, string(*r.spec.Path.ReplacePrefixMatch))
  }
  }
 

pkg/filters/redirectorv2/redirectorv2_test.go

@@ -22,12 +22,20 @@ import (
  "testing"
 
  "github.com/megaease/easegress/v2/pkg/context"
+ "github.com/megaease/easegress/v2/pkg/object/httpserver/routers"
  "github.com/megaease/easegress/v2/pkg/protocols/httpprot"
  "github.com/stretchr/testify/assert"
 
  gwapis "sigs.k8s.io/gateway-api/apis/v1"
 )
 
+type fakeMuxPath struct {
+ routers.Path
+}
+
+func (mp *fakeMuxPath) Protocol() string { return "http" }
+func (mp *fakeMuxPath) Rewrite(context *routers.RouteContext) {}
+
 func TestSpecValidate(t *testing.T) {
  tests := []struct {
  name string
@@ -123,7 +131,7 @@ func TestSpecValidate(t *testing.T) {
  },
  },
  expectErr: true,
- errMsg: "invalid path of Redirector, pathPrefix can't be empty",
+ errMsg: "invalid path of Redirector, replacePrefixMatch can't be empty",
  },
  }
 
@@ -169,7 +177,6 @@ func TestRedirectorHandle2(t *testing.T) {
  name: "Redirect prefix",
  reqURL: "http:https://localhost/user/data/profile",
  spec: &Spec{
- PathPrefix: new(string),
  HTTPRequestRedirectFilter: gwapis.HTTPRequestRedirectFilter{
  Path: &gwapis.HTTPPathModifier{
  Type: gwapis.PrefixMatchHTTPPathModifier,
@@ -232,13 +239,15 @@ func TestRedirectorHandle2(t *testing.T) {
  req, _ := httpprot.NewRequest(stdReq)
  ctx := context.New(nil)
  ctx.SetInputRequest(req)
+ ctx.SetRoute(&fakeMuxPath{
+ Path: routers.Path{PathPrefix: "/user/"},
+ })
 
  if tt.spec.Path != nil && tt.spec.Path.ReplaceFullPath != nil {
  *tt.spec.Path.ReplaceFullPath = "/newpath"
  }
 
  if tt.spec.Path != nil && tt.spec.Path.ReplacePrefixMatch != nil {
- *tt.spec.PathPrefix = "/user/"
  *tt.spec.Path.ReplacePrefixMatch = "/account/"
  }
 

pkg/object/httpserver/mux.go

@@ -129,7 +129,8 @@ func (mi *muxInstance) putRouteToCache(req *httpprot.Request, rc *cachedRoute) {
 }
 
 func newMux(httpStat *httpstat.HTTPStat, topN *httpstat.TopN,
- metrics *metrics, mapper context.MuxMapper) *mux {
+ metrics *metrics, mapper context.MuxMapper,
+) *mux {
  m := &mux{
  httpStat: httpStat,
  topN: topN,
@@ -267,6 +268,8 @@ func (mi *muxInstance) serveHTTP(stdw http.ResponseWriter, stdr *http.Request) {
 
  routeCtx := routers.NewContext(req)
  route := mi.search(routeCtx)
+ ctx.SetRoute(route.route)
+
  var respHeader http.Header
 
  defer func() {

pkg/object/httpserver/routers/ordered/router.go

@@ -86,6 +86,10 @@ func newMuxPath(p *routers.Path) *muxPath {
  }
 }
 
+func (mp *muxPath) Protocol() string {
+ return "http"
+}
+
 func (mp *muxPath) matchPath(path string) bool {
  if mp.Path.Path == "" && mp.PathPrefix == "" && mp.pathRE == nil {
  return true

pkg/object/httpserver/routers/radixtree/router.go

@@ -485,6 +485,10 @@ func (mp *muxPath) initRewrite() {
  mp.rewriteTemplate = template.Must(template.New("").Parse(repl))
 }
 
+func (mp *muxPath) Protocol() string {
+ return "http"
+}
+
 func (mp *muxPath) Rewrite(context *routers.RouteContext) {
  req := context.Request
 

pkg/object/httpserver/routers/routers.go

@@ -25,6 +25,7 @@ import (
  "net/http"
  "net/url"
 
+ "github.com/megaease/easegress/v2/pkg/protocols"
  "github.com/megaease/easegress/v2/pkg/protocols/httpprot"
 )
 
@@ -49,12 +50,24 @@ type (
 
  // Route is the corresponding route interface for different routing policies.
  Route interface {
+ protocols.Route
+
  // Rewrite for path rewriting.
  Rewrite(context *RouteContext)
  // GetBackend is used to get the backend corresponding to the route.
  GetBackend() string
  // GetClientMaxBodySize is used to get the clientMaxBodySize corresponding to the route.
  GetClientMaxBodySize() int64
+
+ // NOTE: Currently we only support path information in readonly.
+ // Without further requirements, we choose not to expose too much information.
+
+ // GetExactPath is used to get the exact path corresponding to the route.
+ GetExactPath() string
+ // GetPathPrefix is used to get the path prefix corresponding to the route.
+ GetPathPrefix() string
+ // GetPathRegexp is used to get the path regexp corresponding to the route.
+ GetPathRegexp() string
  }
 
  // Params are used to store the variables in the search path and their corresponding values.

pkg/object/httpserver/routers/spec.go

@@ -252,6 +252,21 @@ func (p *Path) GetClientMaxBodySize() int64 {
  return p.ClientMaxBodySize
 }
 
+// GetExactPath returns the exact path of the route.
+func (p *Path) GetExactPath() string {
+ return p.Path
+}
+
+// GetPathPrefix returns the path prefix of the route.
+func (p *Path) GetPathPrefix() string {
+ return p.PathPrefix
+}
+
+// GetPathRegexp returns the path regexp of the route.
+func (p *Path) GetPathRegexp() string {
+ return p.PathRegexp
+}
+
 func (hs Headers) init() {
  for _, h := range hs {
  if h.Regexp != "" {

pkg/protocols/protocols.go

@@ -150,3 +150,10 @@ type Protocol interface {
  NewResponseInfo() interface{}
  BuildResponse(respInfo interface{}) (Response, error)
 }
+
+// Route is the interface of a route.
+// Filters could assert the real type according to the protocol.
+type Route interface {
+ // Protocol returns the canonical name of the protocol in lower case, such as http, grpc.
+ Protocol() string
+}