feat(aws-events-targets): centralized module for cloudwatch event tar…

…gets (#2343)

Start moving all implementations of `IEventRuleTarget` into a centralized
module to adhere with the new AWS Construct Library guideline for integrations.

This change includes the implementation of the following event rule targets:

- `targets.SnsTopic`
- `targets.CodeBuildProject`

BREAKING CHANGE: `sns.Topic` no longer implements `IEventRuleTarget`. Use `@aws-cdk/aws-events-targets.SnsTopic` instead.
* `codebuild.Project` no longer implements `IEventRuleTarget`. Use `@aws-cdk/aws-events-targets.CodeBuildProject`

packages/@aws-cdk/aws-codebuild/README.md

@@ -152,12 +152,14 @@ by events via an event rule.
 
 ### Using Project as an event target
 
-The `Project` construct implements the `IEventRuleTarget` interface. This means
-that it can be used as a target for event rules:
+The `@aws-cdk/aws-events-targets.CodeBuildProject` allows using an AWS CodeBuild
+project as a AWS CloudWatch event rule target:
 
 ```ts
 // start build when a commit is pushed
-codeCommitRepository.onCommit('OnCommit', project);
+const targets = require('@aws-cdk/aws-events-targets');
+
+codeCommitRepository.onCommit('OnCommit', new targets.CodeBuildProject(project));
 ```
 
 ### Using Project as an event source

packages/@aws-cdk/aws-codebuild/lib/project.ts

@@ -16,7 +16,7 @@ const CODEPIPELINE_TYPE = 'CODEPIPELINE';
 const S3_BUCKET_ENV = 'SCRIPT_S3_BUCKET';
 const S3_KEY_ENV = 'SCRIPT_S3_KEY';
 
-export interface IProject extends IResource, events.IEventRuleTarget, iam.IGrantable {
+export interface IProject extends IResource, iam.IGrantable {
   /** The ARN of this Project. */
   readonly projectArn: string;
 
@@ -167,9 +167,6 @@ export abstract class ProjectBase extends Resource implements IProject {
   /** The IAM service Role of this Project. */
   public abstract readonly role?: iam.IRole;
 
-  /** A role used by CloudWatch events to trigger a build */
-  private eventsRole?: iam.Role;
-
   public abstract export(): ProjectImportProps;
 
   /**
@@ -347,27 +344,6 @@ export abstract class ProjectBase extends Resource implements IProject {
       ...props,
     });
   }
-
-  /**
-   * Allows using build projects as event rule targets.
-   */
-  public asEventRuleTarget(_ruleArn: string, _ruleId: string): events.EventRuleTargetProps {
-    if (!this.eventsRole) {
-      this.eventsRole = new iam.Role(this, 'EventsRole', {
-        assumedBy: new iam.ServicePrincipal('events.amazonaws.com')
-      });
-
-      this.eventsRole.addToPolicy(new iam.PolicyStatement()
-        .addAction('codebuild:StartBuild')
-        .addResource(this.projectArn));
-    }
-
-    return {
-      id: this.node.id,
-      arn: this.projectArn,
-      roleArn: this.eventsRole.roleArn,
-    };
-  }
 }
 
 class ImportedProject extends ProjectBase {

packages/@aws-cdk/aws-codecommit/test/integ.codecommit-events.expected.json

@@ -44,42 +44,6 @@
     },
     "MyTopic86869434": {
       "Type": "AWS::SNS::Topic"
-    },
-    "MyTopicPolicy12A5EC17": {
-      "Type": "AWS::SNS::TopicPolicy",
-      "Properties": {
-        "PolicyDocument": {
-          "Statement": [
-            {
-              "Action": "sns:Publish",
-              "Effect": "Allow",
-              "Principal": {
-                "Service": {
-                  "Fn::Join": [
-                    "",
-                    [
-                      "events.",
-                      {
-                        "Ref": "AWS::URLSuffix"
-                      }
-                    ]
-                  ]
-                }
-              },
-              "Resource": {
-                "Ref": "MyTopic86869434"
-              },
-              "Sid": "0"
-            }
-          ],
-          "Version": "2012-10-17"
-        },
-        "Topics": [
-          {
-            "Ref": "MyTopic86869434"
-          }
-        ]
-      }
     }
   }
 }

packages/@aws-cdk/aws-codecommit/test/integ.codecommit-events.ts

@@ -8,6 +8,13 @@ const stack = new cdk.Stack(app, 'aws-cdk-codecommit-events');
 const repo = new codecommit.Repository(stack, 'Repo', { repositoryName: 'aws-cdk-codecommit-events' });
 const topic = new sns.Topic(stack, 'MyTopic');
 
-repo.onReferenceCreated('OnReferenceCreated', topic);
+// we can't use @aws-cdk/aws-events-targets.SnsTopic here because it will
+// create a cyclic dependency with codebuild, so we just fake it
+repo.onReferenceCreated('OnReferenceCreated', {
+  asEventRuleTarget: () => ({
+    arn: topic.topicArn,
+    id: 'MyTopic'
+  })
+});
 
 app.run();

packages/@aws-cdk/aws-codepipeline-actions/package.json

@@ -63,6 +63,7 @@
   "devDependencies": {
     "@aws-cdk/assert": "^0.28.0",
     "@aws-cdk/aws-cloudtrail": "^0.28.0",
+    "@aws-cdk/aws-events-targets": "^0.28.0",
     "@types/lodash": "^4.14.123",
     "cdk-build-tools": "^0.28.0",
     "cdk-integ-tools": "^0.28.0",

packages/@aws-cdk/aws-codepipeline-actions/test/integ.pipeline-events.ts

@@ -3,6 +3,7 @@
 import codebuild = require('@aws-cdk/aws-codebuild');
 import codecommit = require('@aws-cdk/aws-codecommit');
 import codepipeline = require('@aws-cdk/aws-codepipeline');
+import targets = require('@aws-cdk/aws-events-targets');
 import sns = require('@aws-cdk/aws-sns');
 import cdk = require('@aws-cdk/cdk');
 import cpactions = require('../lib');
@@ -42,17 +43,17 @@ pipeline.addStage({
 
 const topic = new sns.Topic(stack, 'MyTopic');
 
-pipeline.onStateChange('OnPipelineStateChange').addTarget(topic, {
+pipeline.onStateChange('OnPipelineStateChange').addTarget(new targets.SnsTopic(topic), {
   textTemplate: 'Pipeline <pipeline> changed state to <state>',
   pathsMap: {
     pipeline: '$.detail.pipeline',
     state: '$.detail.state'
   }
 });
 
-sourceStage.onStateChange('OnSourceStateChange', topic);
+sourceStage.onStateChange('OnSourceStateChange', new targets.SnsTopic(topic));
 
-sourceAction.onStateChange('OnActionStateChange', topic).addEventPattern({
+sourceAction.onStateChange('OnActionStateChange', new targets.SnsTopic(topic)).addEventPattern({
   detail: { state: [ 'STARTED' ] }
 });
 

packages/@aws-cdk/aws-codepipeline-actions/test/test.pipeline.ts

@@ -2,6 +2,7 @@ import { expect, haveResource, haveResourceLike, SynthUtils } from '@aws-cdk/ass
 import codebuild = require('@aws-cdk/aws-codebuild');
 import codecommit = require('@aws-cdk/aws-codecommit');
 import codepipeline = require('@aws-cdk/aws-codepipeline');
+import targets = require('@aws-cdk/aws-events-targets');
 import lambda = require('@aws-cdk/aws-lambda');
 import s3 = require('@aws-cdk/aws-s3');
 import sns = require('@aws-cdk/aws-sns');
@@ -188,7 +189,7 @@ export = {
       ],
     });
 
-    pipeline.onStateChange('OnStateChange', topic, {
+    pipeline.onStateChange('OnStateChange', new targets.SnsTopic(topic), {
       description: 'desc',
       scheduleExpression: 'now',
       eventPattern: {

packages/@aws-cdk/aws-events-targets/.gitignore

@@ -0,0 +1,16 @@
+*.js
+tsconfig.json
+tslint.json
+*.js.map
+*.d.ts
+*.generated.ts
+dist
+lib/generated/resources.ts
+.jsii
+
+.LAST_BUILD
+.nyc_output
+coverage
+.nycrc
+.LAST_PACKAGE
+*.snk

packages/@aws-cdk/aws-events-targets/.npmignore

@@ -0,0 +1,16 @@
+# Don't include original .ts files when doing `npm pack`
+*.ts
+!*.d.ts
+coverage
+.nyc_output
+*.tgz
+
+dist
+.LAST_PACKAGE
+.LAST_BUILD
+!*.js
+
+# Include .jsii
+!.jsii
+
+*.snk