Expose gitSource programmatically in the App class

Author: otaviomacedo

packages/aws-cdk-lib/core/lib/app.ts

@@ -1,5 +1,6 @@
 import type { Construct, IConstruct } from 'constructs';
 import * as fs from 'fs-extra';
+import { getGitSource } from './private/git-source';
 import { PRIVATE_CONTEXT_DEFAULT_STACK_SYNTHESIZER } from './private/private-context';
 import type { ICustomSynthesis } from './private/synthesis';
 import { addCustomSynthesis } from './private/synthesis';
@@ -178,6 +179,14 @@ export class App extends Stage {
    */
   public readonly _treeMetadata: boolean;
 
+  /**
+   * Git source information for the repository containing this CDK app.
+   * Contains the repository URL and commit hash, or `undefined` if
+   * git information is not available or has been disabled via
+   * `CDK_DISABLE_GIT_SOURCE`.
+   */
+  public readonly gitSource: { readonly repository: string; readonly commit: string } | undefined;
+
   /**
    * Initializes a CDK application.
    * @param props initialization properties
@@ -219,6 +228,7 @@ export class App extends Stage {
     }
 
     this._treeMetadata = props.treeMetadata ?? true;
+    this.gitSource = getGitSource();
   }
 
   private loadContext(defaults: { [key: string]: string } = { }, final: { [key: string]: string } = {}) {

packages/aws-cdk-lib/core/lib/stack.ts

@@ -1430,7 +1430,8 @@ export class Stack extends Construct implements ITaggable {
     }
 
     const metadata: { [key: string]: any } = {};
-    const gitSource = getGitSource();
+    const app = App.isApp(this.node.root) ? this.node.root as App : undefined;
+    const gitSource = app?.gitSource ?? getGitSource();
     if (gitSource) {
       metadata['AWS::CloudFormation::Source'] = {
         Repository: gitSource.repository,

packages/aws-cdk-lib/core/test/app.test.ts

@@ -382,6 +382,42 @@ describe('app', () => {
     const stack = new Stack(stage, 'TestStack');
     expect(App.of(stack)).toBe(app);
   });
+
+  test('gitSource is populated by default and propagated to stacks', () => {
+    const savedEnv = process.env.CDK_DISABLE_GIT_SOURCE;
+    process.env.CDK_DISABLE_GIT_SOURCE = '';
+    try {
+      const app = new App();
+      const stack = new Stack(app, 'Stack');
+      new CfnResource(stack, 'Resource', { type: 'MyResource' });
+
+      expect(app.gitSource).toBeDefined();
+      expect(typeof app.gitSource!.repository).toBe('string');
+      expect(typeof app.gitSource!.commit).toBe('string');
+      expect(app.gitSource!.commit).toMatch(/^[a-f0-9]{40}$/);
+
+      const assembly = app.synth();
+      const template = assembly.getStackByName(stack.stackName).template;
+      const source = template?.Metadata?.['AWS::CloudFormation::Source'];
+      expect(source).toEqual({
+        Repository: app.gitSource!.repository,
+        Commit: app.gitSource!.commit,
+      });
+    } finally {
+      process.env.CDK_DISABLE_GIT_SOURCE = savedEnv;
+    }
+  });
+
+  test('gitSource is undefined when CDK_DISABLE_GIT_SOURCE is set', () => {
+    const savedEnv = process.env.CDK_DISABLE_GIT_SOURCE;
+    process.env.CDK_DISABLE_GIT_SOURCE = '1';
+    try {
+      const app = new App();
+      expect(app.gitSource).toBeUndefined();
+    } finally {
+      process.env.CDK_DISABLE_GIT_SOURCE = savedEnv;
+    }
+  });
 });
 
 class MyConstruct extends Construct {