129 lines
3.7 KiB
Go
129 lines
3.7 KiB
Go
/*
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Copyright 2021 The Dapr Authors
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package routeralias
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import (
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"context"
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"errors"
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"fmt"
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"net/http"
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"reflect"
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"github.com/gorilla/mux"
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"gopkg.in/yaml.v3"
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mdutils "github.com/dapr/components-contrib/metadata"
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"github.com/dapr/components-contrib/middleware"
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"github.com/dapr/kit/logger"
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)
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type contextKey int
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const varsKey contextKey = iota
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// Middleware is an routeralias middleware.
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type Middleware struct {
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logger logger.Logger
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router *mux.Router
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}
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// NewMiddleware returns a new routerchecker middleware.
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func NewMiddleware(logger logger.Logger) middleware.Middleware {
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return &Middleware{logger: logger}
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}
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// GetHandler retruns the HTTP handler provided by the middleware.
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func (m *Middleware) GetHandler(_ context.Context, metadata middleware.Metadata) (
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func(next http.Handler) http.Handler, error,
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) {
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if err := m.createRouterFromMetadata(metadata); err != nil {
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return nil, err
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}
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return func(next http.Handler) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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var match mux.RouteMatch
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if m.router.Match(r, &match) {
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ctx := context.WithValue(r.Context(), varsKey, match.Vars)
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r = r.WithContext(ctx)
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match.Handler.ServeHTTP(w, r)
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}
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next.ServeHTTP(w, r)
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})
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}, nil
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}
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func (m *Middleware) createRouterFromMetadata(metadata middleware.Metadata) error {
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m.router = mux.NewRouter()
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if len(metadata.Properties) == 0 {
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return nil
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}
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// Check if using legacy metadata
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routesVal, _ := mdutils.GetMetadataProperty(metadata.Properties, "routes")
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if len(metadata.Properties) > 1 || routesVal == "" {
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m.logger.Warn("Listing routes as key-value pairs is deprecated. Please use the 'routes' property instead. See: https://docs.dapr.io/reference/components-reference/supported-middleware/middleware-routeralias/")
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for key, value := range metadata.Properties {
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if key == "" || value == "" {
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return errors.New("invalid key/value pair in metadata: must not be empty")
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}
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m.router.Handle(key, m.routerConvert(value))
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}
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} else {
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routes := map[string]string{}
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err := yaml.Unmarshal([]byte(routesVal), &routes)
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if err != nil {
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return fmt.Errorf("failed to decode 'routes' property as JSON or YAML: %w", err)
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}
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for key, value := range routes {
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m.router.Handle(key, m.routerConvert(value))
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}
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}
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return nil
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}
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func (m *Middleware) routerConvert(daprRouter string) http.Handler {
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return http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
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req.URL.Path = daprRouter
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params := vars(req)
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if len(params) > 0 {
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vals := req.URL.Query()
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for key, val := range params {
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vals.Add(key, val)
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}
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req.URL.RawQuery = vals.Encode()
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req.RequestURI = daprRouter + "?" + req.URL.RawQuery
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}
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})
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}
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// vars returns the route variables for the current request, if any.
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func vars(r *http.Request) map[string]string {
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if rv := r.Context().Value(varsKey); rv != nil {
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return rv.(map[string]string)
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}
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return nil
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}
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func (m *Middleware) GetComponentMetadata() (metadataInfo mdutils.MetadataMap) {
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metadataStruct := struct {
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Routes string `mapstructure:"routes"`
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}{}
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mdutils.GetMetadataInfoFromStructType(reflect.TypeOf(metadataStruct), &metadataInfo, mdutils.MiddlewareType)
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return
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}
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