/
gateway.go
258 lines (245 loc) · 8.69 KB
/
gateway.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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
package rest
import (
"fmt"
lru "github.com/hashicorp/golang-lru"
"github.com/unionj-cloud/go-doudou/v2/framework/cache"
"github.com/unionj-cloud/go-doudou/v2/framework/config"
"github.com/unionj-cloud/go-doudou/v2/framework/registry"
"github.com/unionj-cloud/go-doudou/v2/framework/registry/constants"
"github.com/unionj-cloud/go-doudou/v2/framework/registry/etcd"
"github.com/unionj-cloud/go-doudou/v2/framework/registry/nacos"
"github.com/unionj-cloud/go-doudou/v2/framework/registry/zk"
"github.com/wubin1989/nacos-sdk-go/v2/vo"
"go.etcd.io/etcd/client/v3"
"net/http"
"net/http/httputil"
"net/url"
"os"
"regexp"
"strconv"
"strings"
)
// Headers borrowed from labstack/echo
const (
HeaderAccept = "Accept"
HeaderAcceptEncoding = "Accept-Encoding"
HeaderAllow = "Allow"
HeaderAuthorization = "Authorization"
HeaderContentDisposition = "Content-Disposition"
HeaderContentEncoding = "Content-Encoding"
HeaderContentLength = "Content-Length"
HeaderContentType = "Content-Type"
HeaderCookie = "Cookie"
HeaderSetCookie = "Set-Cookie"
HeaderIfModifiedSince = "If-Modified-Since"
HeaderLastModified = "Last-Modified"
HeaderLocation = "Location"
HeaderUpgrade = "Upgrade"
HeaderVary = "Vary"
HeaderWWWAuthenticate = "WWW-Authenticate"
HeaderXForwardedFor = "X-Forwarded-For"
HeaderXForwardedProto = "X-Forwarded-Proto"
HeaderXForwardedProtocol = "X-Forwarded-Protocol"
HeaderXForwardedSsl = "X-Forwarded-Ssl"
HeaderXUrlScheme = "X-Url-Scheme"
HeaderXHTTPMethodOverride = "X-HTTP-Method-Override"
HeaderXRealIP = "X-Real-IP"
HeaderXRequestID = "X-Request-ID"
HeaderXRequestedWith = "X-Requested-With"
HeaderServer = "Server"
HeaderOrigin = "Origin"
// Access control
HeaderAccessControlRequestMethod = "Access-Control-Request-Method"
HeaderAccessControlRequestHeaders = "Access-Control-Request-Headers"
HeaderAccessControlAllowOrigin = "Access-Control-Allow-Origin"
HeaderAccessControlAllowMethods = "Access-Control-Allow-Methods"
HeaderAccessControlAllowHeaders = "Access-Control-Allow-Headers"
HeaderAccessControlAllowCredentials = "Access-Control-Allow-Credentials"
HeaderAccessControlExposeHeaders = "Access-Control-Expose-Headers"
HeaderAccessControlMaxAge = "Access-Control-Max-Age"
// Security
HeaderStrictTransportSecurity = "Strict-Transport-Security"
HeaderXContentTypeOptions = "X-Content-Type-Options"
HeaderXXSSProtection = "X-XSS-Protection"
HeaderXFrameOptions = "X-Frame-Options"
HeaderContentSecurityPolicy = "Content-Security-Policy"
HeaderContentSecurityPolicyReportOnly = "Content-Security-Policy-Report-Only"
HeaderXCSRFToken = "X-CSRF-Token"
HeaderReferrerPolicy = "Referrer-Policy"
)
type ProxyTarget struct {
Name string
URL *url.URL
}
type ProxyConfig struct {
ProviderStore cache.IStore
// To customize the transport to remote.
// Examples: If custom TLS certificates are required.
Transport http.RoundTripper
// ModifyResponse defines function to modify response from ProxyTarget.
ModifyResponse func(*http.Response) error
}
func captureTokens(pattern *regexp.Regexp, input string) *strings.Replacer {
groups := pattern.FindAllStringSubmatch(input, -1)
if groups == nil {
return nil
}
values := groups[0][1:]
replace := make([]string, 2*len(values))
for i, v := range values {
j := 2 * i
replace[j] = "$" + strconv.Itoa(i+1)
replace[j+1] = v
}
return strings.NewReplacer(replace...)
}
func getPath(r *http.Request) string {
path := r.URL.RawPath
if path == "" {
path = r.URL.Path
}
return path
}
func isWebSocket(r *http.Request) bool {
upgrade := r.Header.Get(HeaderUpgrade)
return strings.ToLower(upgrade) == "websocket"
}
func Proxy(proxyConfig ProxyConfig) func(inner http.Handler) http.Handler {
if proxyConfig.ProviderStore == nil {
arc, _ := lru.NewARC(128)
proxyConfig.ProviderStore = arc
}
if proxyConfig.Transport == nil {
proxyConfig.Transport = http.DefaultTransport
}
return func(inner http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if isWebSocket(r) || r.Header.Get(HeaderAccept) == "text/event-stream" {
http.Error(w, "not support", http.StatusBadGateway)
return
}
parts := strings.Split(r.URL.Path, "/")
if len(parts) <= 1 {
http.Error(w, "request url must be prefixed / + service name", http.StatusBadGateway)
return
}
serviceName := parts[1]
modes := strings.Split(os.Getenv("GDD_SERVICE_DISCOVERY_MODE"), ",")
// TODO call Close method to release resource
var provider registry.IServiceProvider
for _, mode := range modes {
switch mode {
case constants.SD_NACOS:
cluster := config.GddNacosClusterName.LoadOrDefault(config.DefaultGddNacosClusterName)
group := config.GddNacosGroupName.LoadOrDefault(config.DefaultGddNacosGroupName)
_, err := nacos.NamingClient.GetService(vo.GetServiceParam{
Clusters: []string{cluster},
ServiceName: serviceName,
GroupName: group,
})
if err != nil {
continue
}
if value, ok := proxyConfig.ProviderStore.Get(serviceName); ok {
if provider, ok = value.(*nacos.WRRServiceProvider); ok {
break
}
}
provider = nacos.NewWRRServiceProvider(serviceName, nacos.WithNacosClusters([]string{cluster}), nacos.WithNacosGroupName(group))
proxyConfig.ProviderStore.Add(serviceName, provider)
case constants.SD_ETCD:
getResponse, err := etcd.EtcdCli.Get(r.Context(), serviceName+"/", clientv3.WithPrefix())
if err != nil || getResponse.Count == 0 {
continue
}
if value, ok := proxyConfig.ProviderStore.Get(serviceName); ok {
if provider, ok = value.(*etcd.SWRRServiceProvider); ok {
break
}
}
provider = etcd.NewSWRRServiceProvider(serviceName)
proxyConfig.ProviderStore.Add(serviceName, provider)
case constants.SD_ZK:
if value, ok := proxyConfig.ProviderStore.Get(serviceName); ok {
if provider, ok = value.(*zk.SWRRServiceProvider); ok {
break
}
}
group := config.GddServiceGroup.LoadOrDefault(config.DefaultGddServiceGroup)
version := config.GddServiceVersion.LoadOrDefault(config.DefaultGddServiceVersion)
provider = zk.NewSWRRServiceProvider(zk.ServiceConfig{
Name: serviceName,
Group: group,
Version: version,
})
proxyConfig.ProviderStore.Add(serviceName, provider)
default:
}
if provider != nil {
break
}
}
if provider == nil {
http.Error(w, fmt.Sprintf("available server for service %s not found", serviceName), http.StatusBadGateway)
return
}
k := regexp.MustCompile(strings.Replace(fmt.Sprintf("/%s/*", serviceName), "*", "(\\S*)", -1))
replacer := captureTokens(k, getPath(r))
if replacer != nil {
r.URL.Path = replacer.Replace("/$1")
}
parsed, err := url.Parse(provider.SelectServer())
if err != nil {
http.Error(w, fmt.Sprintf("available server for service %s not found with error: %s", serviceName, err), http.StatusBadGateway)
return
}
tgt := &ProxyTarget{
Name: serviceName,
URL: parsed,
}
proxyHTTP(tgt, proxyConfig).ServeHTTP(w, r)
})
}
}
func singleJoiningSlash(a, b string) string {
aslash := strings.HasSuffix(a, "/")
bslash := strings.HasPrefix(b, "/")
switch {
case aslash && bslash:
return a + b[1:]
case !aslash && !bslash:
return a + "/" + b
}
return a + b
}
func proxyHTTP(tgt *ProxyTarget, config ProxyConfig) http.Handler {
target := tgt.URL
targetQuery := target.RawQuery
director := func(req *http.Request) {
req.URL.Scheme = target.Scheme
req.URL.Host = target.Host
req.Host = target.Host
req.URL.Path = singleJoiningSlash(target.Path, req.URL.Path)
if targetQuery == "" || req.URL.RawQuery == "" {
req.URL.RawQuery = targetQuery + req.URL.RawQuery
} else {
req.URL.RawQuery = targetQuery + "&" + req.URL.RawQuery
}
req.Header.Set("Host", target.Host)
if _, ok := req.Header["User-Agent"]; !ok {
// explicitly disable User-Agent so it's not set to default value
req.Header.Set("User-Agent", "")
}
}
proxy := &httputil.ReverseProxy{Director: director}
proxy.ErrorHandler = func(w http.ResponseWriter, req *http.Request, err error) {
desc := target.String()
if tgt.Name != "" {
desc = fmt.Sprintf("%s(%s)", tgt.Name, tgt.URL.String())
}
http.Error(w, fmt.Sprintf("remote %s unreachable, could not forward: %v", desc, err), http.StatusBadGateway)
}
proxy.Transport = config.Transport
proxy.ModifyResponse = config.ModifyResponse
return proxy
}