Merge pull request #2799 from taras/scaffolder-add-github-auth-to-preparer

fix: Add authentication to GitHub preparer

.changeset/cyan-plants-dress.md

@@ -0,0 +1,5 @@
+---
+'example-backend': patch
+---
+
+Pass GitHub token into Scaffolder GitHub Preparer

.changeset/pretty-cups-joke.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend': patch
+---
+
+Add authentication token to Scaffolder GitHub Preparer

packages/backend/src/plugins/scaffolder.ts

@@ -47,13 +47,12 @@ export default async function createPlugin({
   templaters.register('cra', craTemplater);
 
   const filePreparer = new FilePreparer();
-  const githubPreparer = new GithubPreparer();
+
   const gitlabPreparer = new GitlabPreparer(config);
   const azurePreparer = new AzurePreparer(config);
   const preparers = new Preparers();
 
   preparers.register('file', filePreparer);
-  preparers.register('github', githubPreparer);
   preparers.register('gitlab', gitlabPreparer);
   preparers.register('gitlab/api', gitlabPreparer);
   preparers.register('azure/api', azurePreparer);
@@ -75,6 +74,10 @@ export default async function createPlugin({
         token: githubToken,
         repoVisibility,
       });
+
+      const githubPreparer = new GithubPreparer({ token: githubToken });
+
+      preparers.register('github', githubPreparer);
       publishers.register('file', githubPublisher);
       publishers.register('github', githubPublisher);
     } catch (e) {

plugins/scaffolder-backend/src/scaffolder/stages/prepare/github.test.ts

@@ -90,7 +90,6 @@ describe('GitHubPreparer', () => {
       {},
     );
   });
-
   it('return the temp directory with the path to the folder if it is specified', async () => {
     const preparer = new GithubPreparer();
     mockEntity.spec.path = './template/test/1/2/3';
@@ -100,4 +99,20 @@ describe('GitHubPreparer', () => {
       /\/template\/test\/1\/2\/3$/,
     );
   });
+  it('calls the clone command with the token when provided', async () => {
+    const preparer = new GithubPreparer({ token: 'abc' });
+    await preparer.prepare(mockEntity);
+    expect(mocks.Clone.clone).toHaveBeenNthCalledWith(
+      1,
+      'https://github.com/benjdlambert/backstage-graphql-template',
+      expect.any(String),
+      {
+        fetchOpts: {
+          callbacks: {
+            credentials: expect.any(Function),
+          },
+        },
+      },
+    );
+  });
 });

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

@@ -21,11 +21,18 @@ import { parseLocationAnnotation } from '../helpers';
 import { InputError } from '@backstage/backend-common';
 import { PreparerBase } from './types';
 import GitUriParser from 'git-url-parse';
-import { Clone } from 'nodegit';
+import { Clone, Cred } from 'nodegit';
 
 export class GithubPreparer implements PreparerBase {
+  token?: string;
+
+  constructor(params: { token?: string } = {}) {
+    this.token = params.token;
+  }
+
   async prepare(template: TemplateEntityV1alpha1): Promise<string> {
     const { protocol, location } = parseLocationAnnotation(template);
+    const { token } = this;
 
     if (protocol !== 'github') {
       throw new InputError(
@@ -45,9 +52,19 @@ export class GithubPreparer implements PreparerBase {
       template.spec.path ?? '.',
     );
 
-    await Clone.clone(repositoryCheckoutUrl, tempDir, {
-      // TODO(blam): Maybe need some auth here?
-    });
+    const cloneOptions = token
+      ? {
+          fetchOpts: {
+            callbacks: {
+              credentials() {
+                return Cred.userpassPlaintextNew(token, 'x-oauth-basic');
+              },
+            },
+          },
+        }
+      : {};
+
+    await Clone.clone(repositoryCheckoutUrl, tempDir, cloneOptions);
 
     return path.resolve(tempDir, templateDirectory);
   }