# AWS Pipelines with Github Release trigger in CDK

### Problem

CDK pipeline supports GitHub webhook, but on `branch push events`, not on `release events`.

### UPDATE 2022

The after [migrating to the modern CDK Pipeline API](https://github.com/aws/aws-cdk/blob/master/packages/%40aws-cdk/pipelines/ORIGINAL_API.md) this approach no longer works.

Instead we have setup a GitHub action that is triggered on `release` and pushes to a `release_to_production` branch and use the CDK Pipeline to trigger from the push event on that instead.

This ends up with a cleaner CDK setup even if relying on a branch rather than a release directly

### Solution...


Disable triggers when you create a `GitHubSourceAction`
```ts
   const ghAction = new codepipeline_actions.GitHubSourceAction({
      actionName: 'GitHubRelease',
      ....
      trigger: codepipeline_actions.GitHubTrigger.NONE, // we will add our own below
    });

    // Everything else
    const synthAction = pipelines.SimpleSynthAction.standardNpmSynth({
      sourceArtifact,
      cloudAssemblyArtifact,
      buildCommand: 'echo "HELLO!"',
    });

    const myPipeLine = new pipelines.CdkPipeline(this, 'Pipeline', {
      pipelineName: 'MyAppPipeline',
      cloudAssemblyArtifact,

      sourceAction: ghAction,
      synthAction,
    });
``` 
 
Create your own webhook and change the filters to look at `$.action` and match to `published` events
```ts
    new codepipeline.CfnWebhook(this, 'WebhookResource', {
      authentication: 'GITHUB_HMAC',
      authenticationConfiguration: {
        secretToken: SecretValue.secretsManager('GITHUB_TEST_PIPELINE').toString(),
      },
      filters: [
        {
          jsonPath: '$.action',
          matchEquals: 'published',
        },
      ],
      targetAction: ghAction.actionProperties.actionName,
      targetPipeline: myPipeLine.codePipeline.pipelineName,
      targetPipelineVersion: 1,
      registerWithThirdParty: true,
    });
```

#### Tips

- After initial deploy remember to edit the webhook in github to send `release` not `push` events!
- Cloudformation deploy errors maybe based on github credentials access - make sure token valid and has permissions to create a webhook (admin I believe)

#### Useful links

- https://stackoverflow.com/questions/52516087/trigger-aws-codepipeline-by-github-release-webhook
- https://www.linkedin.com/pulse/aws-codepipeline-github-releases-geo-nicolaidis/
- https://docs.github.com/en/actions/reference/events-that-trigger-workflows#release
- https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-codepipeline-webhook.html