fix(codepipeline): cannot trigger on all tags anymore in EcrSourceAct…

…ion (aws#17270)

The EcrSourceAction could previously be used to trigger on changes to all tags of an image. As part of the fix aws#13818, the imageTag was defaulted to latest if not provided. Therefore it was no longer possible to call the underlying onCloudTrailImagePushed function with an undefined imageTag to watch changes on all tags.

Reintroduce triggering on all tags by passing an empty string as the imageTag.

Fixes aws#13818


----

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

packages/@aws-cdk/aws-codepipeline-actions/lib/ecr/source-action.ts

@@ -36,6 +36,7 @@ export interface EcrSourceVariables {
 export interface EcrSourceActionProps extends codepipeline.CommonAwsActionProps {
   /**
    * The image tag that will be checked for changes.
+   * Provide an empty string to trigger on changes to any tag.
    *
    * @default 'latest'
    */
@@ -95,7 +96,7 @@ export class EcrSourceAction extends Action {
 
     this.props.repository.onCloudTrailImagePushed(Names.nodeUniqueId(stage.pipeline.node) + 'SourceEventRule', {
       target: new targets.CodePipeline(stage.pipeline),
-      imageTag: this.props.imageTag ?? 'latest',
+      imageTag: this.props.imageTag === '' ? undefined : (this.props.imageTag ?? 'latest'),
     });
 
     // the Action Role also needs to write to the Pipeline's bucket
@@ -104,7 +105,7 @@ export class EcrSourceAction extends Action {
     return {
       configuration: {
         RepositoryName: this.props.repository.repositoryName,
-        ImageTag: this.props.imageTag,
+        ImageTag: this.props.imageTag ? this.props.imageTag : undefined, // `''` is falsy in JS/TS
       },
     };
   }

packages/@aws-cdk/aws-codepipeline-actions/test/ecr/ecr-source-action.test.ts

@@ -1,4 +1,5 @@
 import '@aws-cdk/assert-internal/jest';
+import { ABSENT } from '@aws-cdk/assert-internal';
 import * as codebuild from '@aws-cdk/aws-codebuild';
 import * as codepipeline from '@aws-cdk/aws-codepipeline';
 import * as ecr from '@aws-cdk/aws-ecr';
@@ -60,6 +61,78 @@ describe('ecr source action', () => {
       });
 
 
+      expect(stack).toHaveResourceLike('AWS::Events::Rule', {
+        'EventPattern': {
+          'detail': {
+            'requestParameters': {
+              'imageTag': ['latest'],
+            },
+          },
+        },
+      });
+    });
+
+    test('watches all tags when imageTag provided as empty string', () => {
+      const stack = new Stack();
+
+      const sourceOutput = new codepipeline.Artifact();
+      const ecrSourceAction = new cpactions.EcrSourceAction({
+        actionName: 'Source',
+        output: sourceOutput,
+        repository: ecr.Repository.fromRepositoryName(stack, 'Repo', 'repo'),
+        imageTag: '',
+      });
+
+      new codepipeline.Pipeline(stack, 'Pipeline', {
+        stages: [
+          {
+            stageName: 'Source',
+            actions: [ecrSourceAction],
+          },
+          {
+            stageName: 'Build',
+            actions: [
+              new cpactions.CodeBuildAction({
+                actionName: 'Build',
+                project: new codebuild.PipelineProject(stack, 'MyProject'),
+                input: sourceOutput,
+                environmentVariables: {
+                  ImageDigest: { value: ecrSourceAction.variables.imageDigest },
+                },
+              }),
+            ],
+          },
+        ],
+      });
+
+      expect(stack).toHaveResourceLike('AWS::Events::Rule', {
+        'EventPattern': {
+          'source': [
+            'aws.ecr',
+          ],
+          'detail': {
+            'requestParameters': {
+              'imageTag': ABSENT,
+            },
+          },
+        },
+      });
+
+      expect(stack).toHaveResourceLike('AWS::CodePipeline::Pipeline', {
+        'Stages': [
+          {
+            'Name': 'Source',
+            'Actions': [
+              {
+                'Name': 'Source',
+                'Configuration': {
+                  'ImageTag': ABSENT,
+                },
+              },
+            ],
+          },
+        ],
+      });
     });
   });
 });

packages/@aws-cdk/aws-codepipeline-actions/test/integ.pipeline-ecr-source.expected.json

@@ -415,4 +415,4 @@
       }
     }
   }
-}
+}