micro/api/handler/api/api.go
2019-06-05 10:22:28 +01:00

118 lines
2.8 KiB
Go

// Package api provides an http-rpc handler which provides the entire http request over rpc
package api
import (
"net/http"
goapi "github.com/micro/go-micro/api"
"github.com/micro/go-micro/api/handler"
"github.com/micro/go-micro/client"
"github.com/micro/go-micro/errors"
"github.com/micro/go-micro/selector"
"github.com/micro/go-micro/util/ctx"
api "github.com/micro/go-micro/api/proto"
)
type apiHandler struct {
opts handler.Options
s *goapi.Service
}
const (
Handler = "api"
)
// API handler is the default handler which takes api.Request and returns api.Response
func (a *apiHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
request, err := requestToProto(r)
if err != nil {
er := errors.InternalServerError("go.micro.api", err.Error())
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(500)
w.Write([]byte(er.Error()))
return
}
var service *goapi.Service
if a.s != nil {
// we were given the service
service = a.s
} else if a.opts.Router != nil {
// try get service from router
s, err := a.opts.Router.Route(r)
if err != nil {
er := errors.InternalServerError("go.micro.api", err.Error())
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(500)
w.Write([]byte(er.Error()))
return
}
service = s
} else {
// we have no way of routing the request
er := errors.InternalServerError("go.micro.api", "no route found")
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(500)
w.Write([]byte(er.Error()))
return
}
// create request and response
c := a.opts.Service.Client()
req := c.NewRequest(service.Name, service.Endpoint.Name, request)
rsp := &api.Response{}
// create the context from headers
cx := ctx.FromRequest(r)
// create strategy
so := selector.WithStrategy(strategy(service.Services))
if err := c.Call(cx, req, rsp, client.WithSelectOption(so)); err != nil {
w.Header().Set("Content-Type", "application/json")
ce := errors.Parse(err.Error())
switch ce.Code {
case 0:
w.WriteHeader(500)
default:
w.WriteHeader(int(ce.Code))
}
w.Write([]byte(ce.Error()))
return
} else if rsp.StatusCode == 0 {
rsp.StatusCode = http.StatusOK
}
for _, header := range rsp.GetHeader() {
for _, val := range header.Values {
w.Header().Add(header.Key, val)
}
}
if len(w.Header().Get("Content-Type")) == 0 {
w.Header().Set("Content-Type", "application/json")
}
w.WriteHeader(int(rsp.StatusCode))
w.Write([]byte(rsp.Body))
}
func (a *apiHandler) String() string {
return "api"
}
func NewHandler(opts ...handler.Option) handler.Handler {
options := handler.NewOptions(opts...)
return &apiHandler{
opts: options,
}
}
func WithService(s *goapi.Service, opts ...handler.Option) handler.Handler {
options := handler.NewOptions(opts...)
return &apiHandler{
opts: options,
s: s,
}
}