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| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "bufio" |
| 5 | + "bytes" |
| 6 | + "encoding/json" |
| 7 | + "fmt" |
| 8 | + "io" |
| 9 | + "net/http" |
| 10 | + "net/url" |
| 11 | + "os" |
| 12 | + "strings" |
| 13 | + "sync" |
| 14 | + "time" |
| 15 | + |
| 16 | + "github.com/sourcegraph/log" |
| 17 | + |
| 18 | + "github.com/google/uuid" |
| 19 | +) |
| 20 | + |
| 21 | +type ProxyServer struct { |
| 22 | + accessToken string |
| 23 | + tokenMutex sync.RWMutex |
| 24 | + client *http.Client |
| 25 | + azureEndpoint *url.URL |
| 26 | + logger log.Logger |
| 27 | +} |
| 28 | + |
| 29 | +func (ps *ProxyServer) readSecretFile(path string) (string, error) { |
| 30 | + data, err := os.ReadFile(path) |
| 31 | + if err != nil { |
| 32 | + return "", err |
| 33 | + } |
| 34 | + return strings.TrimSpace(string(data)), nil |
| 35 | +} |
| 36 | + |
| 37 | +func (ps *ProxyServer) generateHeaders(bearerToken string) map[string]string { |
| 38 | + return map[string]string{ |
| 39 | + "correlationId": uuid.New().String(), |
| 40 | + "dataClassification": "sensitive", |
| 41 | + "dataSource": "internet", |
| 42 | + "Authorization": "Bearer " + bearerToken, |
| 43 | + } |
| 44 | +} |
| 45 | + |
| 46 | +func (ps *ProxyServer) updateAccessToken() { |
| 47 | + for { |
| 48 | + token, err := ps.getAccessToken() |
| 49 | + if err != nil { |
| 50 | + ps.logger.Fatal("Error getting access token: %v", log.Error(err)) |
| 51 | + } else { |
| 52 | + ps.tokenMutex.Lock() |
| 53 | + ps.accessToken = token |
| 54 | + ps.tokenMutex.Unlock() |
| 55 | + ps.logger.Info("Access token updated") |
| 56 | + } |
| 57 | + time.Sleep(1 * time.Minute) |
| 58 | + } |
| 59 | +} |
| 60 | + |
| 61 | +func (ps *ProxyServer) initializeAzureEndpoint() { |
| 62 | + var err error |
| 63 | + azure_endpoint, err := ps.readSecretFile("/run/secrets/azure_endpoint") |
| 64 | + if err != nil { |
| 65 | + ps.logger.Fatal("error reading OAUTH_URL: %v", log.Error(err)) |
| 66 | + } |
| 67 | + ps.azureEndpoint, err = url.Parse(azure_endpoint) |
| 68 | + if err != nil { |
| 69 | + ps.logger.Fatal("Invalid AZURE_ENDPOINT: %v", log.Error(err)) |
| 70 | + } |
| 71 | +} |
| 72 | + |
| 73 | +func (ps *ProxyServer) initializeClient() { |
| 74 | + ps.client = &http.Client{ |
| 75 | + Transport: &http.Transport{ |
| 76 | + MaxIdleConns: 400, |
| 77 | + MaxIdleConnsPerHost: 400, |
| 78 | + IdleConnTimeout: 90 * time.Second, |
| 79 | + DisableKeepAlives: false, |
| 80 | + }, |
| 81 | + Timeout: 30 * time.Second, |
| 82 | + } |
| 83 | +} |
| 84 | + |
| 85 | +func (ps *ProxyServer) getAccessToken() (string, error) { |
| 86 | + url, err := ps.readSecretFile("/run/secrets/oauth_url") |
| 87 | + if err != nil { |
| 88 | + return "", fmt.Errorf("error reading OAUTH_URL: %v", err) |
| 89 | + } |
| 90 | + clientID, err := ps.readSecretFile("/run/secrets/client_id") |
| 91 | + if err != nil { |
| 92 | + return "", fmt.Errorf("error reading CLIENT_ID: %v", err) |
| 93 | + } |
| 94 | + clientSecret, err := ps.readSecretFile("/run/secrets/client_secret") |
| 95 | + if err != nil { |
| 96 | + return "", fmt.Errorf("error reading CLIENT_SECRET: %v", err) |
| 97 | + } |
| 98 | + |
| 99 | + data := map[string]string{ |
| 100 | + "client_id": clientID, |
| 101 | + "client_secret": clientSecret, |
| 102 | + "scope": "azureopenai-readwrite", |
| 103 | + "grant_type": "client_credentials", |
| 104 | + } |
| 105 | + |
| 106 | + jsonData, err := json.Marshal(data) |
| 107 | + if err != nil { |
| 108 | + return "", fmt.Errorf("error marshalling JSON: %v", err) |
| 109 | + } |
| 110 | + |
| 111 | + req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData)) |
| 112 | + if err != nil { |
| 113 | + return "", fmt.Errorf("error creating request: %v", err) |
| 114 | + } |
| 115 | + |
| 116 | + req.Header.Set("Content-Type", "application/json") |
| 117 | + |
| 118 | + resp, err := ps.client.Do(req) |
| 119 | + if err != nil { |
| 120 | + return "", fmt.Errorf("error making request: %v", err) |
| 121 | + } |
| 122 | + defer resp.Body.Close() |
| 123 | + |
| 124 | + if resp.StatusCode != http.StatusOK { |
| 125 | + return "", fmt.Errorf("request failed with status: %v", resp.Status) |
| 126 | + } |
| 127 | + |
| 128 | + var result map[string]interface{} |
| 129 | + if err := json.NewDecoder(resp.Body).Decode(&result); err != nil { |
| 130 | + return "", fmt.Errorf("error decoding response: %v", err) |
| 131 | + } |
| 132 | + |
| 133 | + token, ok := result["access_token"].(string) |
| 134 | + if !ok { |
| 135 | + return "", fmt.Errorf("access token not found in response") |
| 136 | + } |
| 137 | + |
| 138 | + return token, nil |
| 139 | +} |
| 140 | + |
| 141 | +func (ps *ProxyServer) handleProxy(w http.ResponseWriter, req *http.Request) { |
| 142 | + target := ps.azureEndpoint.ResolveReference(req.URL) |
| 143 | + // Create a proxy request |
| 144 | + proxyReq, err := http.NewRequest(req.Method, target.String(), req.Body) |
| 145 | + if err != nil { |
| 146 | + http.Error(w, "Internal Server Error", http.StatusInternalServerError) |
| 147 | + return |
| 148 | + } |
| 149 | + |
| 150 | + // Copy headers from the original request |
| 151 | + for header, values := range req.Header { |
| 152 | + for _, value := range values { |
| 153 | + proxyReq.Header.Add(header, value) |
| 154 | + } |
| 155 | + } |
| 156 | + |
| 157 | + ps.tokenMutex.RLock() |
| 158 | + bearerToken := ps.accessToken |
| 159 | + ps.tokenMutex.RUnlock() |
| 160 | + // Add generated headers |
| 161 | + headers := ps.generateHeaders(bearerToken) |
| 162 | + for key, value := range headers { |
| 163 | + proxyReq.Header.Set(key, value) |
| 164 | + } |
| 165 | + proxyReq.Header.Set("Api-Key", bearerToken) |
| 166 | + |
| 167 | + resp, err := ps.client.Do(proxyReq) |
| 168 | + if err != nil { |
| 169 | + http.Error(w, "Bad Gateway", http.StatusBadGateway) |
| 170 | + return |
| 171 | + } |
| 172 | + defer resp.Body.Close() |
| 173 | + |
| 174 | + // Write the headers and status code from the response to the client |
| 175 | + for header, values := range resp.Header { |
| 176 | + for _, value := range values { |
| 177 | + w.Header().Add(header, value) |
| 178 | + } |
| 179 | + } |
| 180 | + w.WriteHeader(resp.StatusCode) |
| 181 | + |
| 182 | + // Stream the response body to the client |
| 183 | + reader := bufio.NewReader(resp.Body) |
| 184 | + buf := make([]byte, 32*1024) |
| 185 | + for { |
| 186 | + n, err := reader.Read(buf) |
| 187 | + if err != nil && err != io.EOF { |
| 188 | + ps.logger.Error("Error reading response body: %v", log.Error(err)) |
| 189 | + http.Error(w, "Error reading response from upstream server", http.StatusBadGateway) |
| 190 | + return |
| 191 | + } |
| 192 | + if n == 0 { |
| 193 | + break |
| 194 | + } |
| 195 | + if _, writeErr := w.Write(buf[:n]); writeErr != nil { |
| 196 | + ps.logger.Fatal("Error writing response: %v", log.Error(writeErr)) |
| 197 | + break |
| 198 | + } |
| 199 | + if flusher, ok := w.(http.Flusher); ok { |
| 200 | + flusher.Flush() |
| 201 | + } |
| 202 | + } |
| 203 | +} |
| 204 | + |
| 205 | +func main() { |
| 206 | + liblog := log.Init(log.Resource{ |
| 207 | + Name: "Special Oauth Server", |
| 208 | + }) |
| 209 | + defer liblog.Sync() |
| 210 | + |
| 211 | + logger := log.Scoped("server") |
| 212 | + |
| 213 | + ps := &ProxyServer{ |
| 214 | + logger: logger, |
| 215 | + } |
| 216 | + ps.initializeClient() |
| 217 | + ps.initializeAzureEndpoint() |
| 218 | + go ps.updateAccessToken() |
| 219 | + http.HandleFunc("/", ps.handleProxy) |
| 220 | + logger.Info("HTTP Proxy server is running on port 8080") |
| 221 | + if err := http.ListenAndServe(":8080", nil); err != nil { |
| 222 | + logger.Fatal("Failed to start HTTP server: %v", log.Error(err)) |
| 223 | + } |
| 224 | +} |
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