-
Notifications
You must be signed in to change notification settings - Fork 0
/
http.go
214 lines (180 loc) · 4.34 KB
/
http.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
// Package http provides a micro rpc to http proxy
package http
import (
"bytes"
"context"
"io"
"io/ioutil"
"net/http"
"net/url"
"path"
"github.com/chnkenc/go-micro/errors"
"github.com/chnkenc/go-micro/proxy"
"github.com/chnkenc/go-micro/server"
)
// Proxy will proxy rpc requests as http POST requests. It is a server.Proxy
type Proxy struct {
options proxy.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 ""
}
func getTopic(hdr map[string]string) string {
ep := hdr["Micro-Topic"]
if len(ep) > 0 && ep[0] == '/' {
return ep
}
return "/" + hdr["Micro-Topic"]
}
// ProcessMessage handles incoming asynchronous messages
func (p *Proxy) ProcessMessage(ctx context.Context, msg server.Message) error {
if p.Endpoint == "" {
p.Endpoint = proxy.DefaultEndpoint
}
// get the header
hdr := msg.Header()
// get topic
// use /topic as endpoint
endpoint := getTopic(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(msg.Topic(), err.Error())
}
u.Path = path.Join(u.Path, endpoint)
endpoint = u.String()
}
// send to backend
hreq, err := http.NewRequest("POST", endpoint, bytes.NewReader(msg.Body()))
if err != nil {
return errors.InternalServerError(msg.Topic(), 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(msg.Topic(), err.Error())
}
// read body
b, err := ioutil.ReadAll(hrsp.Body)
hrsp.Body.Close()
if err != nil {
return errors.InternalServerError(msg.Topic(), err.Error())
}
if hrsp.StatusCode != 200 {
return errors.New(msg.Topic(), string(b), int32(hrsp.StatusCode))
}
return nil
}
// 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())
}
}
}
func (p *Proxy) String() string {
return "http"
}
// 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 ...proxy.Option) proxy.Proxy {
var options proxy.Options
for _, o := range opts {
o(&options)
}
p := new(Proxy)
p.Endpoint = options.Endpoint
p.options = options
return p
}