Merge pull request #5709 from TejasQ/tejask/2494

Scaffolder: Enable branch protection on new repo

.changeset/thick-ads-smash.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend': patch
+---
+
+Add branch protection for default branches of scaffolded GitHub repositories

plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts

@@ -19,7 +19,10 @@ import {
   ScmIntegrationRegistry,
 } from '@backstage/integration';
 import { Octokit } from '@octokit/rest';
-import { initRepoAndPush } from '../../../stages/publish/helpers';
+import {
+  enableBranchProtectionOnDefaultRepoBranch,
+  initRepoAndPush,
+} from '../../../stages/publish/helpers';
 import { getRepoSourceDirectory, parseRepoUrl } from './util';
 import { createTemplateAction } from '../../createTemplateAction';
 
@@ -171,7 +174,7 @@ export function createPublishGithubAction(options: {
               description: description,
             });
 
-      const { data } = await repoCreationPromise;
+      const { data: newRepo } = await repoCreationPromise;
       if (access?.startsWith(`${owner}/`)) {
         const [, team] = access.split('/');
         await client.teams.addOrUpdateRepoPermissionsInOrg({
@@ -212,8 +215,8 @@ export function createPublishGithubAction(options: {
         }
       }
 
-      const remoteUrl = data.clone_url;
-      const repoContentsUrl = `${data.html_url}/blob/master`;
+      const remoteUrl = newRepo.clone_url;
+      const repoContentsUrl = `${newRepo.html_url}/blob/master`;
 
       await initRepoAndPush({
         dir: getRepoSourceDirectory(ctx.workspacePath, ctx.input.sourcePath),
@@ -225,6 +228,18 @@ export function createPublishGithubAction(options: {
         logger: ctx.logger,
       });
 
+      try {
+        await enableBranchProtectionOnDefaultRepoBranch({
+          owner,
+          client,
+          repoName: newRepo.name,
+        });
+      } catch (e) {
+        throw new Error(
+          `Failed to add branch protection to '${newRepo.name}', ${e}`,
+        );
+      }
+
       ctx.output('remoteUrl', remoteUrl);
       ctx.output('repoContentsUrl', repoContentsUrl);
     },

plugins/scaffolder-backend/src/scaffolder/stages/publish/github.ts

@@ -15,7 +15,10 @@
  */
 
 import { PublisherBase, PublisherOptions, PublisherResult } from './types';
-import { initRepoAndPush } from './helpers';
+import {
+  enableBranchProtectionOnDefaultRepoBranch,
+  initRepoAndPush,
+} from './helpers';
 import {
   GitHubIntegrationConfig,
   GithubCredentialsProvider,
@@ -26,6 +29,7 @@ import path from 'path';
 
 export type RepoVisibilityOptions = 'private' | 'internal' | 'public';
 
+/** @deprecated use createPublishGithubAction instead */
 export class GithubPublisher implements PublisherBase {
   static async fromConfig(
     config: GitHubIntegrationConfig,
@@ -99,6 +103,17 @@ export class GithubPublisher implements PublisherBase {
       /\.git$/,
       '/blob/master/catalog-info.yaml',
     );
+
+    try {
+      await enableBranchProtectionOnDefaultRepoBranch({
+        owner,
+        client,
+        repoName: name,
+      });
+    } catch (e) {
+      throw new Error(`Failed to add branch protection to '${name}', ${e}`);
+    }
+
     return { remoteUrl, catalogInfoUrl };
   }
 
@@ -130,7 +145,7 @@ export class GithubPublisher implements PublisherBase {
             description,
           });
 
-    const { data } = await repoCreationPromise;
+    const { data: newRepo } = await repoCreationPromise;
 
     try {
       if (access?.startsWith(`${owner}/`)) {
@@ -156,6 +171,7 @@ export class GithubPublisher implements PublisherBase {
         `Failed to add access to '${access}'. Status ${e.status} ${e.message}`,
       );
     }
-    return data?.clone_url;
+
+    return newRepo.clone_url;
   }
 }

plugins/scaffolder-backend/src/scaffolder/stages/publish/helpers.ts

@@ -17,6 +17,7 @@
 import globby from 'globby';
 import { Logger } from 'winston';
 import { Git } from '@backstage/backend-common';
+import { Octokit } from '@octokit/rest';
 
 export async function initRepoAndPush({
   dir,
@@ -67,3 +68,50 @@ export async function initRepoAndPush({
     remote: 'origin',
   });
 }
+
+type BranchProtectionOptions = {
+  client: Octokit;
+  owner: string;
+  repoName: string;
+  isRetry?: boolean;
+};
+
+export const enableBranchProtectionOnDefaultRepoBranch = async ({
+  repoName,
+  client,
+  owner,
+}: BranchProtectionOptions): Promise<void> => {
+  const tryOnce = () => {
+    return client.repos.updateBranchProtection({
+      mediaType: {
+        /**
+         * 👇 we need this preview because allowing a custom
+         * reviewer count on branch protection is a preview
+         * feature
+         *
+         * More here: https://docs.github.com/en/rest/overview/api-previews#require-multiple-approving-reviews
+         */
+        previews: ['luke-cage-preview'],
+      },
+      owner,
+      repo: repoName,
+      branch: 'master',
+      required_status_checks: { strict: true, contexts: [] },
+      restrictions: null,
+      enforce_admins: true,
+      required_pull_request_reviews: { required_approving_review_count: 1 },
+    });
+  };
+
+  try {
+    await tryOnce();
+  } catch (e) {
+    if (!e.message.includes('Branch not found')) {
+      throw e;
+    }
+
+    // GitHub has eventual consistency. Fail silently, wait, and try again.
+    await new Promise(resolve => setTimeout(resolve, 600));
+    await tryOnce();
+  }
+};