go-sdk/service/http/invoke.go

79 lines
2.1 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"
)
// AddServiceInvocationHandler appends provided service invocation handler with its route to the service.
func (s *Server) AddServiceInvocationHandler(route string, fn func(ctx context.Context, in *common.InvocationEvent) (out *common.Content, err error)) error {
if route == "" {
return fmt.Errorf("service route required")
}
if fn == nil {
return fmt.Errorf("invocation 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) {
// capture http args
e := &common.InvocationEvent{
Verb: r.Method,
QueryString: r.URL.RawQuery,
ContentType: r.Header.Get("Content-type"),
}
// check for post with no data
if r.ContentLength > 0 {
content, err := ioutil.ReadAll(r.Body)
if err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
e.Data = content
}
// execute handler
o, err := fn(r.Context(), e)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
// write to response if handler returned data
if o != nil && o.Data != nil {
if o.ContentType != "" {
w.Header().Set("Content-type", o.ContentType)
}
if _, err := w.Write(o.Data); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
}
})))
return nil
}