fix(cli): warning to upgrade to bootstrap version >= undefined (#18489)

When we try to assume the lookup role and fail, we print out a warning
telling the user to upgrade to the required bootstrap stack version.

In cases where the user is not using the default stack synthesizer
(legacy, custom, etc.) the cli might not have information on the lookup
role. In those cases where we don't have the necessary information on
the ARN of the lookup role or the required bootstrap version, we will
not print any warnings.


----

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

Author: corymhall

Diff for: packages/aws-cdk/lib/api/cloudformation-deployments.ts

@@ -96,14 +96,20 @@ export async function prepareSdkWithLookupRoleFor(
       if (version < stack.lookupRole.requiresBootstrapStackVersion) {
         throw new Error(`Bootstrap stack version '${stack.lookupRole.requiresBootstrapStackVersion}' is required, found version '${version}'.`);
       }
-    } else if (!stackSdk.didAssumeRole) {
+      // we may not have assumed the lookup role because one was not provided
+      // if that is the case then don't print the upgrade warning
+    } else if (!stackSdk.didAssumeRole && stack.lookupRole?.requiresBootstrapStackVersion) {
       warning(upgradeMessage);
     }
     return { ...stackSdk, resolvedEnvironment };
   } catch (e) {
     debug(e);
-    warning(warningMessage);
-    warning(upgradeMessage);
+    // only print out the warnings if the lookupRole exists AND there is a required
+    // bootstrap version, otherwise the warnings will print `undefined`
+    if (stack.lookupRole && stack.lookupRole.requiresBootstrapStackVersion) {
+      warning(warningMessage);
+      warning(upgradeMessage);
+    }
     throw (e);
   }
 }

Diff for: packages/aws-cdk/test/cdk-toolkit.test.ts

@@ -127,6 +127,13 @@ describe('readCurrentTemplate', () => {
             },
           },
         },
+        {
+          stackName: 'Test-Stack-A',
+          template,
+          properties: {
+            assumeRoleArn: 'bloop:${AWS::Region}:${AWS::AccountId}',
+          },
+        },
       ],
     });
     mockForEnvironment = jest.fn().mockImplementation(() => { return { sdk: mockCloudExecutable.sdkProvider.sdk, didAssumeRole: true }; });
@@ -145,6 +152,11 @@ describe('readCurrentTemplate', () => {
               StackStatus: 'CREATE_COMPLETE',
               CreationTime: new Date(),
             },
+            {
+              StackName: 'Test-Stack-A',
+              StackStatus: 'CREATE_COMPLETE',
+              CreationTime: new Date(),
+            },
           ],
         };
       },
@@ -329,6 +341,38 @@ describe('readCurrentTemplate', () => {
       assumeRoleArn: 'bloop:here:123456789012',
     });
   });
+
+  test('do not print warnings if lookup role not provided in stack artifact', async () => {
+    // GIVEN
+    mockCloudExecutable.sdkProvider.stubSSM({
+      getParameter() {
+        return {};
+      },
+    });
+    const cdkToolkit = new CdkToolkit({
+      cloudExecutable: mockCloudExecutable,
+      configuration: mockCloudExecutable.configuration,
+      sdkProvider: mockCloudExecutable.sdkProvider,
+      cloudFormation: new CloudFormationDeployments({ sdkProvider: mockCloudExecutable.sdkProvider }),
+    });
+
+    // WHEN
+    await cdkToolkit.deploy({
+      selector: { patterns: ['Test-Stack-A'] },
+    });
+
+    // THEN
+    expect(flatten(stderrMock.mock.calls)).not.toEqual(expect.arrayContaining([
+      expect.stringMatching(/Could not assume/),
+      expect.stringMatching(/please upgrade to bootstrap version/),
+    ]));
+    expect(mockCloudExecutable.sdkProvider.sdk.ssm).not.toHaveBeenCalled();
+    expect(mockForEnvironment.mock.calls.length).toEqual(2);
+    expect(mockForEnvironment.mock.calls[0][2]).toEqual({
+      assumeRoleArn: undefined,
+      assumeRoleExternalId: undefined,
+    });
+  });
 });
 
 describe('deploy', () => {