micro/proxy/http/http.go
2019-08-05 17:44:33 +01:00

150 lines
3.0 KiB
Go

// Package http provides a micro rpc to http proxy
package http
import (
"bytes"
"context"
"io"
"io/ioutil"
"net/http"
"net/url"
"path"
"github.com/micro/go-micro/config/options"
"github.com/micro/go-micro/errors"
"github.com/micro/go-micro/proxy"
"github.com/micro/go-micro/server"
)
// Proxy will proxy rpc requests as http POST requests. It is a server.Proxy
type Proxy struct {
options.Options
// The http backend to call
Endpoint string
// first request
first bool
}
func getMethod(hdr map[string]string) string {
switch hdr["Micro-Method"] {
case "GET", "HEAD", "POST", "PUT", "DELETE", "CONNECT", "OPTIONS", "TRACE", "PATCH":
return hdr["Micro-Method"]
default:
return "POST"
}
}
func getEndpoint(hdr map[string]string) string {
ep := hdr["Micro-Endpoint"]
if len(ep) > 0 && ep[0] == '/' {
return ep
}
return ""
}
// ServeRequest honours the server.Router interface
func (p *Proxy) ServeRequest(ctx context.Context, req server.Request, rsp server.Response) error {
if p.Endpoint == "" {
p.Endpoint = proxy.DefaultEndpoint
}
for {
// get data
body, err := req.Read()
if err == io.EOF {
return nil
}
if err != nil {
return err
}
// get the header
hdr := req.Header()
// get method
method := getMethod(hdr)
// get endpoint
endpoint := getEndpoint(hdr)
// set the endpoint
if len(endpoint) == 0 {
endpoint = p.Endpoint
} else {
// add endpoint to backend
u, err := url.Parse(p.Endpoint)
if err != nil {
return errors.InternalServerError(req.Service(), err.Error())
}
u.Path = path.Join(u.Path, endpoint)
endpoint = u.String()
}
// send to backend
hreq, err := http.NewRequest(method, endpoint, bytes.NewReader(body))
if err != nil {
return errors.InternalServerError(req.Service(), err.Error())
}
// set the headers
for k, v := range hdr {
hreq.Header.Set(k, v)
}
// make the call
hrsp, err := http.DefaultClient.Do(hreq)
if err != nil {
return errors.InternalServerError(req.Service(), err.Error())
}
// read body
b, err := ioutil.ReadAll(hrsp.Body)
hrsp.Body.Close()
if err != nil {
return errors.InternalServerError(req.Service(), err.Error())
}
// set response headers
hdr = map[string]string{}
for k, _ := range hrsp.Header {
hdr[k] = hrsp.Header.Get(k)
}
// write the header
rsp.WriteHeader(hdr)
// write the body
err = rsp.Write(b)
if err == io.EOF {
return nil
}
if err != nil {
return errors.InternalServerError(req.Service(), err.Error())
}
}
return nil
}
// NewSingleHostProxy returns a router which sends requests to a single http backend
func NewSingleHostProxy(url string) proxy.Proxy {
return &Proxy{
Endpoint: url,
}
}
// NewProxy returns a new proxy which will route using a http client
func NewProxy(opts ...options.Option) proxy.Proxy {
p := new(Proxy)
p.Options = options.NewOptions(opts...)
p.Options.Init(options.WithString("http"))
// get endpoint
ep, ok := p.Options.Values().Get("proxy.endpoint")
if ok {
p.Endpoint = ep.(string)
}
return p
}