go-sdk/service/http/binding.go

86 lines
2.2 KiB
Go

/*
Copyright 2021 The Dapr Authors
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package http
import (
"context"
"fmt"
"io/ioutil"
"net/http"
"strings"
"github.com/dapr/go-sdk/service/common"
)
// AddBindingInvocationHandler appends provided binding invocation handler with its route to the service.
func (s *Server) AddBindingInvocationHandler(route string, fn func(ctx context.Context, in *common.BindingEvent) (out []byte, err error)) error {
if route == "" {
return fmt.Errorf("binding route required")
}
if fn == nil {
return fmt.Errorf("binding handler required")
}
if !strings.HasPrefix(route, "/") {
route = fmt.Sprintf("/%s", route)
}
s.mux.Handle(route, optionsHandler(http.HandlerFunc(
func(w http.ResponseWriter, r *http.Request) {
var content []byte
if r.ContentLength > 0 {
body, err := ioutil.ReadAll(r.Body)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
content = body
}
// assuming Dapr doesn't pass multiple values for key
meta := map[string]string{}
for k, values := range r.Header {
// TODO: Need to figure out how to parse out only the headers set in the binding + Traceparent
// if k == "raceparent" || strings.HasPrefix(k, "dapr") {
for _, v := range values {
meta[k] = v
}
// }
}
// execute handler
in := &common.BindingEvent{
Data: content,
Metadata: meta,
}
out, err := fn(r.Context(), in)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if out == nil {
out = []byte("{}")
}
w.Header().Add("Content-Type", "application/json")
if _, err := w.Write(out); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
})))
return nil
}