feat: Support apiKey for GO Feature Flag relay proxy v1.7.0 (#310)

Co-authored-by: Michael Beemer <[email protected]>

Author: thomaspoignant

libs/providers/go-feature-flag/src/lib/errors/unauthorized.ts

@@ -0,0 +1,12 @@
+import { ErrorCode, OpenFeatureError } from '@openfeature/js-sdk'
+
+// Unauthorized is an error send when the provider do an unauthorized call to the relay proxy.
+export class Unauthorized extends OpenFeatureError {
+  code: ErrorCode
+
+  constructor(message: string) {
+    super(message)
+    Object.setPrototypeOf(this, Unauthorized.prototype)
+    this.code = ErrorCode.GENERAL
+  }
+}

libs/providers/go-feature-flag/src/lib/go-feature-flag-provider.spec.ts

@@ -12,6 +12,7 @@ import MockAdapter from 'axios-mock-adapter';
 import { ProxyNotReady } from './errors/proxyNotReady';
 import { ProxyTimeout } from './errors/proxyTimeout';
 import { UnknownError } from './errors/unknownError';
+import { Unauthorized } from './errors/unauthorized';
 import { GoFeatureFlagProvider } from './go-feature-flag-provider';
 import { GoFeatureFlagProxyResponse } from './model';
 
@@ -80,7 +81,7 @@ describe('GoFeatureFlagProvider', () => {
             expect(result.errorCode).toEqual(ErrorCode.PARSE_ERROR)
           })
       });
-  
+
       it('unknown error codes should return GENERAL code', async () => {
         const flagName = 'random-other-other-flag';
         const targetingKey = 'user-key';
@@ -132,6 +133,22 @@ describe('GoFeatureFlagProvider', () => {
           );
         });
     });
+    it('should throw an error if invalid api key is propvided', async () => {
+      const flagName = 'unauthorized';
+      const targetingKey = 'user-key';
+      const dns = `${endpoint}v1/feature/${flagName}/eval`;
+
+      axiosMock.onPost(dns).reply(401, {} as GoFeatureFlagProxyResponse<string>);
+
+      await goff
+        .resolveStringEvaluation(flagName, 'sdk-default', { targetingKey })
+        .catch((err) => {
+          expect(err).toBeInstanceOf(Unauthorized);
+          expect(err.message).toEqual(
+            'invalid token used to contact GO Feature Flag relay proxy instance'
+          );
+        });
+    });
   });
 
   describe('resolveBooleanEvaluation', () => {

libs/providers/go-feature-flag/src/lib/go-feature-flag-provider.ts

@@ -8,18 +8,20 @@ import {
   StandardResolutionReasons,
   TypeMismatchError,
 } from '@openfeature/js-sdk';
-import axios from 'axios';
+import axios, { AxiosRequestConfig } from 'axios';
 import { transformContext } from './context-transformer';
 import { ProxyNotReady } from './errors/proxyNotReady';
 import { ProxyTimeout } from './errors/proxyTimeout';
 import { UnknownError } from './errors/unknownError';
+import { Unauthorized } from './errors/unauthorized';
 import {
   GoFeatureFlagProviderOptions,
   GoFeatureFlagProxyRequest,
   GoFeatureFlagProxyResponse,
   GoFeatureFlagUser,
 } from './model';
 
+
 // GoFeatureFlagProvider is the official Open-feature provider for GO Feature Flag.
 export class GoFeatureFlagProvider implements Provider {
   metadata = {
@@ -30,10 +32,13 @@ export class GoFeatureFlagProvider implements Provider {
   private endpoint: string;
   // timeout in millisecond before we consider the request as a failure
   private timeout: number;
+  // apiKey contains the token to use while calling GO Feature Flag relay proxy
+  private apiKey?: string;
 
   constructor(options: GoFeatureFlagProviderOptions) {
     this.timeout = options.timeout || 0; // default is 0 = no timeout
     this.endpoint = options.endpoint;
+    this.apiKey = options.apiKey;
   }
 
   /**
@@ -149,7 +154,7 @@ export class GoFeatureFlagProvider implements Provider {
    * @throws {ProxyTimeout} When the HTTP call is timing out
    * @throws {UnknownError} When an unknown error occurs
    * @throws {TypeMismatchError} When the type of the variation is not the one expected
-   * @throws {FlagNotFoundError} When the flag does not exists
+   * @throws {FlagNotFoundError} When the flag does not exist
    */
   async resolveEvaluationGoFeatureFlagProxy<T>(
     flagKey: string,
@@ -165,19 +170,24 @@ export class GoFeatureFlagProvider implements Provider {
 
     let apiResponseData: GoFeatureFlagProxyResponse<T>;
     try {
-      const response = await axios.post<GoFeatureFlagProxyResponse<T>>(
-        endpointURL.toString(),
-        request,
-        {
-          headers: {
-            'Content-Type': 'application/json',
-            Accept: 'application/json',
-          },
-          timeout: this.timeout,
-        }
-      );
+      const reqConfig: AxiosRequestConfig  = {
+        headers: {
+          'Content-Type': 'application/json',
+          Accept: 'application/json',
+        },
+        timeout: this.timeout,
+      };
+
+      if (this.apiKey) {
+        reqConfig.headers?.put('Authorization', `Bearer ${this.apiKey}`);
+      }
+
+      const response = await axios.post<GoFeatureFlagProxyResponse<T>>(endpointURL.toString(), request, reqConfig);
       apiResponseData = response.data;
     } catch (error) {
+      if (axios.isAxiosError(error) && error.response?.status == 401) {
+        throw new Unauthorized('invalid token used to contact GO Feature Flag relay proxy instance');
+      }
       // Impossible to contact the relay-proxy
       if (
         axios.isAxiosError(error) &&

libs/providers/go-feature-flag/src/lib/model.ts

@@ -47,6 +47,12 @@ export interface GoFeatureFlagProxyResponse<T> {
 export interface GoFeatureFlagProviderOptions {
   endpoint: string;
   timeout?: number; // in millisecond
+
+  // apiKey (optional) If the relay proxy is configured to authenticate the requests, you should provide
+  // an API Key to the provider. Please ask the administrator of the relay proxy to provide an API Key.
+  // (This feature is available only if you are using GO Feature Flag relay proxy v1.7.0 or above)
+  // Default: null
+  apiKey?: string;
 }
 
 // GOFeatureFlagResolutionReasons allows to extends resolution reasons