feat(core): support Stage properties in App constructor

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

@@ -1,4 +1,6 @@
 import { Construct } from 'constructs';
+import { Environment } from './environment';
+import { PermissionsBoundary } from './permissions-boundary';
 import * as fs from 'fs-extra';
 import { PRIVATE_CONTEXT_DEFAULT_STACK_SYNTHESIZER } from './private/private-context';
 import { addCustomSynthesis, ICustomSynthesis } from './private/synthesis';
@@ -126,6 +128,47 @@ export interface AppProps {
    * @default - no validation plugins
    */
   readonly policyValidationBeta1?: IPolicyValidationPluginBeta1[];
+
+   /**
+   * Default AWS environment (account/region) for `Stack`s in this `App`.
+   *
+   * Stacks defined inside this `App` with either `region` or `account` missing
+   * from its env will use the corresponding field given here.
+   *
+   * If either `region` or `account`is is not configured for `Stack` (either on
+   * the `Stack` itself or on the containing `App` or `Stage`), the Stack will be
+   * *environment-agnostic*.
+   *
+   * Environment-agnostic stacks can be deployed to any environment, may not be
+   * able to take advantage of all features of the CDK. For example, they will
+   * not be able to use environmental context lookups, will not automatically
+   * translate Service Principals to the right format based on the environment's
+   * AWS partition, and other such enhancements.
+   *
+   * @example
+   *
+   * // Use a concrete account and region to deploy this Stage to
+   * new App({
+   *   env: { account: '123456789012', region: 'us-east-1' },
+   * });
+   *
+   * // Use the CLI's current credentials to determine the target environment
+   * new App({
+   *   env: { account: process.env.CDK_DEFAULT_ACCOUNT, region: process.env.CDK_DEFAULT_REGION },
+   * });
+   *
+   * @default - The environments should be configured on the `Stack`s.
+   */
+   readonly env?: Environment;
+
+   /**
+   * Options for applying a permissions boundary to all IAM Roles
+   * and Users created within this App
+   *
+   * @default - no permissions boundary is applied
+   */
+  readonly permissionsBoundary?: PermissionsBoundary;
+
 }
 
 /**
@@ -168,6 +211,8 @@ export class App extends Stage {
     super(undefined as any, '', {
       outdir: props.outdir ?? process.env[cxapi.OUTDIR_ENV],
       policyValidationBeta1: props.policyValidationBeta1,
+      permissionsBoundary: props.permissionsBoundary,
+      env: props.env,
     });
 
     Object.defineProperty(this, APP_SYMBOL, { value: true });

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

@@ -4,7 +4,7 @@ import { Construct } from 'constructs';
 import * as fs from 'fs-extra';
 import { ContextProvider } from '../../cloud-assembly-schema';
 import * as cxapi from '../../cx-api';
-import { CfnResource, DefaultStackSynthesizer, Stack, StackProps } from '../lib';
+import { CfnResource, DefaultStackSynthesizer, Stack, StackProps, Stage } from '../lib';
 import { Annotations } from '../lib/annotations';
 import { App, AppProps } from '../lib/app';
 
@@ -361,6 +361,37 @@ describe('app', () => {
     expect(app.node.tryGetContext('isNumber')).toEqual(10);
     expect(app.node.tryGetContext('isObject')).toEqual({ isString: 'string', isNumber: 10 });
   });
+  test('Stack inherits unspecified part of the env from App', () => {
+    // GIVEN
+    const app = new App({
+      env: { account: 'account', region: 'region' },
+    });
+
+    // WHEN
+    const stack1 = new Stack(app, 'Stack1', { env: { region: 'elsewhere' } });
+    const stack2 = new Stack(app, 'Stack2', { env: { account: 'tnuocca' } });
+
+    // THEN
+    expect(acctRegion(stack1)).toEqual(['account', 'elsewhere']);
+    expect(acctRegion(stack2)).toEqual(['tnuocca', 'region']);
+  });
+
+  test('envs are inherited deeply', () => {
+    // GIVEN
+    const app = new App({
+      env: { account: 'account', region: 'region' },
+    });
+
+    // WHEN
+    const innerAcct = new Stage(app, 'Acct', { env: { account: 'tnuocca' } });
+    const innerRegion = new Stage(app, 'Rgn', { env: { region: 'elsewhere' } });
+    const innerNeither = new Stage(app, 'Neither');
+
+    // THEN
+    expect(acctRegion(new Stack(innerAcct, 'Stack'))).toEqual(['tnuocca', 'region']);
+    expect(acctRegion(new Stack(innerRegion, 'Stack'))).toEqual(['account', 'elsewhere']);
+    expect(acctRegion(new Stack(innerNeither, 'Stack'))).toEqual(['account', 'region']);
+  });
 });
 
 class MyConstruct extends Construct {
@@ -371,3 +402,7 @@ class MyConstruct extends Construct {
     new CfnResource(this, 'r2', { type: 'ResourceType2', properties: { FromContext: this.node.tryGetContext('ctx1') } });
   }
 }
+
+function acctRegion(s: Stack) {
+  return [s.account, s.region];
+}