Merge pull request #22246 from secustor/fix/rate-limit-message

fix(Github): use `x-ratelimit-remaining` and 429 status code for rate limit detection

.changeset/sweet-ravens-glow.md

@@ -0,0 +1,6 @@
+---
+'@backstage/integration': minor
+'@backstage/backend-common': patch
+---
+
+Fix rate limit detection by looking for HTTP status code 429 and updating the header `x-ratelimit-remaining` to look for in case of a 403 code is returned

packages/backend-common/src/reading/GithubUrlReader.ts

@@ -333,10 +333,7 @@ export class GithubUrlReader implements UrlReader {
       // GitHub returns a 403 response with a couple of headers indicating rate
       // limit status. See more in the GitHub docs:
       // https://docs.github.com/en/rest/overview/resources-in-the-rest-api#rate-limiting
-      if (
-        response.status === 403 &&
-        response.headers.get('X-RateLimit-Remaining') === '0'
-      ) {
+      if (this.integration.parseRateLimitInfo(response).isRateLimited) {
         message += ' (rate limit exceeded)';
       }
 

packages/integration/api-report.md

@@ -4,6 +4,7 @@
 
 ```ts
 import { Config } from '@backstage/config';
+import { ConsumedResponse } from '@backstage/errors';
 import { RestEndpointMethodTypes } from '@octokit/rest';
 
 // @public
@@ -567,6 +568,8 @@ export class GithubIntegration implements ScmIntegration {
   // (undocumented)
   static factory: ScmIntegrationsFactory<GithubIntegration>;
   // (undocumented)
+  parseRateLimitInfo(response: ConsumedResponse): RateLimitInfo;
+  // (undocumented)
   resolveEditUrl(url: string): string;
   // (undocumented)
   resolveUrl(options: {
@@ -694,6 +697,12 @@ export type PersonalAccessTokenCredential = AzureCredentialBase & {
   personalAccessToken: string;
 };
 
+// @public
+export interface RateLimitInfo {
+  // (undocumented)
+  isRateLimited: boolean;
+}
+
 // @public
 export function readAwsS3IntegrationConfig(
   config: Config,

packages/integration/package.json

@@ -35,6 +35,7 @@
   "dependencies": {
     "@azure/identity": "^4.0.0",
     "@backstage/config": "workspace:^",
+    "@backstage/errors": "workspace:^",
     "@octokit/auth-app": "^4.0.0",
     "@octokit/rest": "^19.0.3",
     "cross-fetch": "^4.0.0",

packages/integration/src/github/GithubIntegration.test.ts

@@ -78,6 +78,33 @@ describe('GithubIntegration', () => {
       ),
     ).toBe('https://github.com/backstage/backstage/edit/master/README.md');
   });
+
+  describe('isRateLimited', () => {
+    const integration = new GithubIntegration({ host: 'h.com' });
+
+    it.each`
+      status | ratelimitRemaining | expected
+      ${404} | ${100}             | ${false}
+      ${429} | ${undefined}       | ${true}
+      ${429} | ${100}             | ${true}
+      ${403} | ${100}             | ${false}
+      ${403} | ${0}               | ${true}
+    `(
+      '(statusCode: $status, header: $ratelimitRemaining) === $expected',
+      ({ status, ratelimitRemaining, expected }) => {
+        const headers = new Headers({
+          'x-ratelimit-remaining': ratelimitRemaining,
+        });
+        const result = integration.parseRateLimitInfo({
+          status,
+          headers,
+        } as Response);
+        expect(result).toMatchObject({
+          isRateLimited: expected,
+        });
+      },
+    );
+  });
 });
 
 describe('replaceGithubUrlType', () => {

packages/integration/src/github/GithubIntegration.ts

@@ -15,11 +15,16 @@
  */
 
 import { basicIntegrations, defaultScmResolveUrl } from '../helpers';
-import { ScmIntegration, ScmIntegrationsFactory } from '../types';
+import {
+  RateLimitInfo,
+  ScmIntegration,
+  ScmIntegrationsFactory,
+} from '../types';
 import {
   GithubIntegrationConfig,
   readGithubIntegrationConfigs,
 } from './config';
+import { ConsumedResponse } from '@backstage/errors';
 
 /**
  * A GitHub based integration.
@@ -65,6 +70,15 @@ export class GithubIntegration implements ScmIntegration {
   resolveEditUrl(url: string): string {
     return replaceGithubUrlType(url, 'edit');
   }
+
+  parseRateLimitInfo(response: ConsumedResponse): RateLimitInfo {
+    return {
+      isRateLimited:
+        response.status === 429 ||
+        (response.status === 403 &&
+          response.headers.get('x-ratelimit-remaining') === '0'),
+    };
+  }
 }
 
 /**

packages/integration/src/index.ts

@@ -37,5 +37,6 @@ export type {
   ScmIntegration,
   ScmIntegrationsFactory,
   ScmIntegrationsGroup,
+  RateLimitInfo,
 } from './types';
 export type { ScmIntegrationRegistry } from './registry';

packages/integration/src/types.ts

@@ -108,3 +108,12 @@ export interface ScmIntegrationsGroup<T extends ScmIntegration> {
 export type ScmIntegrationsFactory<T extends ScmIntegration> = (options: {
   config: Config;
 }) => ScmIntegrationsGroup<T>;
+
+/**
+ * Encapsulates information about the RateLimit state
+ *
+ * @public
+ */
+export interface RateLimitInfo {
+  isRateLimited: boolean;
+}

yarn.lock

@@ -4147,6 +4147,7 @@ __metadata:
     "@backstage/cli": "workspace:^"
     "@backstage/config": "workspace:^"
     "@backstage/config-loader": "workspace:^"
+    "@backstage/errors": "workspace:^"
     "@octokit/auth-app": ^4.0.0
     "@octokit/rest": ^19.0.3
     "@types/luxon": ^3.0.0