chore(bootstrap): improve permissions boundary switch message (#24354)

If you were not applying a permissions boundary at all (previously or currently) then you would get a message like `Switching from  to undefined...`. This PR fixes that and updates the wording a little.


----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: corymhall

packages/aws-cdk/lib/api/bootstrap/bootstrap-environment.ts

@@ -139,16 +139,26 @@ export class Bootstrapper {
     *    - the name indicating the custom permissions boundary to be used
     * Re-bootstrapping will NOT be blocked by either tightening or relaxing the permissions' boundary.
     */
-    const currentPermissionsBoundary = current.parameters.InputPermissionsBoundary;
+
+    // InputPermissionsBoundary is an `any` type and if it is not defined it
+    // appears as an empty string ''. We need to force it to evaluate an empty string
+    // as undefined
+    const currentPermissionsBoundary: string | undefined = current.parameters.InputPermissionsBoundary || undefined;
     const inputPolicyName = params.examplePermissionsBoundary ? CDK_BOOTSTRAP_PERMISSIONS_BOUNDARY : params.customPermissionsBoundary;
-    let policyName;
+    let policyName: string | undefined;
     if (inputPolicyName) {
       // If the example policy is not already in place, it must be created.
       const sdk = (await sdkProvider.forEnvironment(environment, Mode.ForWriting)).sdk;
       policyName = await this.getPolicyName(environment, sdk, inputPolicyName, partition, params);
     }
     if (currentPermissionsBoundary !== policyName) {
-      warning(`Switching from ${currentPermissionsBoundary} to ${policyName} as permissions boundary`);
+      if (!currentPermissionsBoundary) {
+        warning(`Adding new permissions boundary ${policyName}`);
+      } else if (!policyName) {
+        warning(`Removing existing permissions boundary ${currentPermissionsBoundary}`);
+      } else {
+        warning(`Changing permissions boundary from ${currentPermissionsBoundary} to ${policyName}`);
+      }
     }
 
     return current.update(

packages/aws-cdk/test/api/bootstrap2.test.ts

@@ -12,9 +12,15 @@ import { mockBootstrapStack, MockSdk, MockSdkProvider } from '../util/mock-sdk';
 let bootstrapper: Bootstrapper;
 let mockGetPolicyIamCode: (params: IAM.Types.GetPolicyRequest) => IAM.Types.GetPolicyResponse;
 let mockCreatePolicyIamCode: (params: IAM.Types.CreatePolicyRequest) => IAM.Types.CreatePolicyResponse;
+let stderrMock: jest.SpyInstance;
 
 beforeEach(() => {
   bootstrapper = new Bootstrapper({ source: 'default' });
+  stderrMock = jest.spyOn(process.stderr, 'write').mockImplementation(() => { return true; });
+});
+
+afterEach(() => {
+  stderrMock.mockRestore();
 });
 
 function mockTheToolkitInfo(stackProps: Partial<AWS.CloudFormation.Stack>) {
@@ -114,6 +120,14 @@ describe('Bootstrapping v2', () => {
   });
 
   test('passes value to PermissionsBoundary', async () => {
+    mockTheToolkitInfo({
+      Parameters: [
+        {
+          ParameterKey: 'InputPermissionsBoundary',
+          ParameterValue: 'existing-pb',
+        },
+      ],
+    });
     await bootstrapper.bootstrapEnvironment(env, sdk, {
       parameters: {
         customPermissionsBoundary: 'permissions-boundary-name',
@@ -125,6 +139,71 @@ describe('Bootstrapping v2', () => {
         InputPermissionsBoundary: 'permissions-boundary-name',
       }),
     }));
+    expect(stderrMock.mock.calls).toEqual(expect.arrayContaining([
+      expect.arrayContaining([
+        expect.stringMatching(/Changing permissions boundary from existing-pb to permissions-boundary-name/),
+      ]),
+    ]));
+  });
+
+  test('permission boundary switch message does not appear', async () => {
+    mockTheToolkitInfo({
+      Parameters: [
+        {
+          ParameterKey: 'InputPermissionsBoundary',
+          ParameterValue: '',
+        },
+      ],
+    });
+    await bootstrapper.bootstrapEnvironment(env, sdk);
+
+    expect(stderrMock.mock.calls).toEqual(expect.arrayContaining([
+      expect.not.arrayContaining([
+        expect.stringMatching(/Changing permissions boundary/),
+      ]),
+    ]));
+  });
+
+  test('adding new permissions boundary', async () => {
+    mockTheToolkitInfo({
+      Parameters: [
+        {
+          ParameterKey: 'InputPermissionsBoundary',
+          ParameterValue: '',
+        },
+      ],
+    });
+    await bootstrapper.bootstrapEnvironment(env, sdk, {
+      parameters: {
+        customPermissionsBoundary: 'permissions-boundary-name',
+      },
+    });
+
+    expect(stderrMock.mock.calls).toEqual(expect.arrayContaining([
+      expect.arrayContaining([
+        expect.stringMatching(/Adding new permissions boundary permissions-boundary-name/),
+      ]),
+    ]));
+  });
+
+  test('removing existing permissions boundary', async () => {
+    mockTheToolkitInfo({
+      Parameters: [
+        {
+          ParameterKey: 'InputPermissionsBoundary',
+          ParameterValue: 'permissions-boundary-name',
+        },
+      ],
+    });
+    await bootstrapper.bootstrapEnvironment(env, sdk, {
+      parameters: {},
+    });
+
+    expect(stderrMock.mock.calls).toEqual(expect.arrayContaining([
+      expect.arrayContaining([
+        expect.stringMatching(/Removing existing permissions boundary permissions-boundary-name/),
+      ]),
+    ]));
   });
 
   test('passing trusted accounts without CFN managed policies results in an error', async () => {