From 9454490a094c2aad60081478115d5b61e2e6d652 Mon Sep 17 00:00:00 2001
From: Adam Ruka <adamruka@amazon.com>
Date: Fri, 2 Nov 2018 17:47:02 -0700
Subject: [PATCH] feat(aws-codepipeline): switch to webhooks instead of polling
 by default for the GitHub source Action.

---
 .../@aws-cdk/app-delivery/test/integ.cicd.ts  |  1 +
 .../test/test.pipeline-actions.ts             |  4 ++-
 .../aws-codepipeline-api/lib/action.ts        |  5 ++++
 .../lib/github-source-action.ts               | 27 ++++++++++++++++---
 .../aws-codepipeline/test/test.pipeline.ts    |  2 +-
 5 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/packages/@aws-cdk/app-delivery/test/integ.cicd.ts b/packages/@aws-cdk/app-delivery/test/integ.cicd.ts
index bf6948588f17e..3f7f81636f052 100644
--- a/packages/@aws-cdk/app-delivery/test/integ.cicd.ts
+++ b/packages/@aws-cdk/app-delivery/test/integ.cicd.ts
@@ -14,6 +14,7 @@ const source = new code.GitHubSourceAction(stack, 'GitHub', {
   owner: 'awslabs',
   repo: 'aws-cdk',
   oauthToken: new cdk.Secret('DummyToken'),
+  pollForSourceChanges: true,
 });
 new cicd.PipelineDeployStackAction(stack, 'DeployStack', {
   stage: pipeline.addStage('Deploy'),
diff --git a/packages/@aws-cdk/aws-cloudformation/test/test.pipeline-actions.ts b/packages/@aws-cdk/aws-cloudformation/test/test.pipeline-actions.ts
index 978303b4f308f..63677172d192a 100644
--- a/packages/@aws-cdk/aws-cloudformation/test/test.pipeline-actions.ts
+++ b/packages/@aws-cdk/aws-cloudformation/test/test.pipeline-actions.ts
@@ -275,11 +275,13 @@ function _stackArn(stackName: string): string {
 }
 
 class PipelineDouble implements cpapi.IPipeline {
+  public readonly pipelineName: string;
   public readonly pipelineArn: string;
   public readonly role: iam.Role;
 
   constructor({ pipelineName, role }: { pipelineName?: string, role: iam.Role }) {
-    this.pipelineArn = cdk.ArnUtils.fromComponents({ service: 'codepipeline', resource: 'pipeline', resourceName: pipelineName || 'TestPipeline' });
+    this.pipelineName = pipelineName || 'TestPipeline';
+    this.pipelineArn = cdk.ArnUtils.fromComponents({ service: 'codepipeline', resource: 'pipeline', resourceName: this.pipelineName });
     this.role = role;
   }
 
diff --git a/packages/@aws-cdk/aws-codepipeline-api/lib/action.ts b/packages/@aws-cdk/aws-codepipeline-api/lib/action.ts
index 5b27dda440972..c3ac1528f9448 100644
--- a/packages/@aws-cdk/aws-codepipeline-api/lib/action.ts
+++ b/packages/@aws-cdk/aws-codepipeline-api/lib/action.ts
@@ -73,6 +73,11 @@ export interface IInternalStage {
  * so this interface can be used as a Target for CloudWatch Events.
  */
 export interface IPipeline extends events.IEventRuleTarget {
+  /**
+   * The name of the Pipeline.
+   */
+  readonly pipelineName: string;
+
   /**
    * The ARN of the Pipeline.
    */
diff --git a/packages/@aws-cdk/aws-codepipeline/lib/github-source-action.ts b/packages/@aws-cdk/aws-codepipeline/lib/github-source-action.ts
index 953c497d7008e..49b77f3e98c84 100644
--- a/packages/@aws-cdk/aws-codepipeline/lib/github-source-action.ts
+++ b/packages/@aws-cdk/aws-codepipeline/lib/github-source-action.ts
@@ -1,5 +1,6 @@
 import actions = require('@aws-cdk/aws-codepipeline-api');
 import cdk = require('@aws-cdk/cdk');
+import { cloudformation } from './codepipeline.generated';
 
 /**
  * Construction properties of the {@link GitHubSourceAction GitHub source action}.
@@ -44,9 +45,10 @@ export interface GitHubSourceActionProps extends actions.CommonActionProps,
   oauthToken: cdk.Secret;
 
   /**
-   * Whether or not AWS CodePipeline should poll for source changes
+   * Whether AWS CodePipeline should poll for source changes.
+   * If this is `false`, the Pipeline will use a webhook to detect source changes instead.
    *
-   * @default true
+   * @default false
    */
   pollForSourceChanges?: boolean;
 }
@@ -66,9 +68,28 @@ export class GitHubSourceAction extends actions.SourceAction {
         Repo: props.repo,
         Branch: props.branch || "master",
         OAuthToken: props.oauthToken,
-        PollForSourceChanges: props.pollForSourceChanges || true
+        PollForSourceChanges: props.pollForSourceChanges || false,
       },
       outputArtifactName: props.outputArtifactName
     });
+
+    if (!props.pollForSourceChanges) {
+      new cloudformation.WebhookResource(this, 'WebhookResource', {
+        authentication: 'GITHUB_HMAC',
+        authenticationConfiguration: {
+          secretToken: props.oauthToken,
+        },
+        filters: [
+          {
+            jsonPath: '$.ref',
+            matchEquals: 'refs/heads/{Branch}',
+          },
+        ],
+        targetAction: this.id,
+        targetPipeline: props.stage.pipeline.pipelineName,
+        targetPipelineVersion: 1,
+        registerWithThirdParty: true,
+      });
+    }
   }
 }
diff --git a/packages/@aws-cdk/aws-codepipeline/test/test.pipeline.ts b/packages/@aws-cdk/aws-codepipeline/test/test.pipeline.ts
index c5ad9900fd361..301995f1dcd5b 100644
--- a/packages/@aws-cdk/aws-codepipeline/test/test.pipeline.ts
+++ b/packages/@aws-cdk/aws-codepipeline/test/test.pipeline.ts
@@ -93,7 +93,7 @@ export = {
           "OAuthToken": {
             "Ref": "GitHubTokenParameterBB166B9D"
           },
-          "PollForSourceChanges": true
+          "PollForSourceChanges": false
           },
           "InputArtifacts": [],
           "Name": "GH",