HowTo

Adding Assets to CDK Staging Bucket

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Today I discovered that you can deploy arbitrary files to the CDK staging bucket with a human readable file name!

This feature is awesome if you are pre-synthing CDK apps to CloudFormation Templates.

My first attempt was to use Asset but it used the file hash for the file name, which could change over time and is not user friendly.

After playing around with a few methods, I discovered that you can do this.

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class MyStack extends Stack{
  constructor(...){
    this.synthesizer.addFileAsset({
      sourceHash: 'RELEASE_NOTES',
      fileName: join(rootDir, 'RELEASE_NOTES.md'),
      packaging: FileAssetPackaging.FILE
    })
  }
}

In the above sample, the sourceHash is used to create the file name: RELEASE_NOTES.md. Since I publish templates under their version prefix, the file hash is unimportant to me!

More Context

We generate pre-synthed templates for very complex applications which are:

  • shared with clients using a S3 bucket policy
  • installed by a non-developer using CloudFormation QuickStart URLs
  • capable of automatically updating itself by checking the bucket for a newer version and initiating a cloudformation update

Including a RELEASE_NOTES.md allows the template consumer to make a more informed decision on when to upgrade.

Cheers!

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