AWS Cloud Development Kit (CDK) for LocalStack

This project provides a thin wrapper script cdklocal for using the AWS CDK library against local APIs provided by LocalStack.

Note: This project replaces the old (deprecated) repo which was a fork of the AWS CDK repo. Instead of forking the repo and applying changes, we now simply provide a simple wrapper script cdklocal which applies runtime patching. The advantage of the new approach is that you should be able to use arbitrary CDK versions under the cover.

Quick Installation

The cdklocal command line is published as an npm library:

$ npm install -g aws-cdk-local aws-cdk
...
$ cdklocal --version
1.65.5

Note: Starting with version 1.65.2, the dependency aws-cdk needs to be installed manually (to decouple the two libraries, and allow using arbitrary versions of aws-cdk under the covers).

(Note: Depending on your local setup, you may or may not have to use the global npm installation flag -g above.)

Mac OS specific MODULE_NOT_FOUND issue

On Mac OS, brew can be used to install AWS CDK, which might result in a MODULE_NOT_FOUND error from cdklocal.
To resolve this, set the NODE_PATH variable pointing to your AWS CDK's node_module folder to expand the lookup path for modules.

$ export NODE_PATH=$NODE_PATH:/opt/homebrew/Cellar/aws-cdk/<CDK_VERSION>/libexec/lib/node_modules

Configurations

The following environment variables can be configured:

• AWS_ENDPOINT_URL: The endpoint URL to connect to (combination of USE_SSL/LOCALSTACK_HOSTNAME/EDGE_PORT below)
• EDGE_PORT (deprecated): Port under which LocalStack edge service is accessible (default: 4566)
• LOCALSTACK_HOSTNAME (deprecated): Target host under which LocalStack edge service is accessible (default: localhost)
• USE_SSL (deprecated): Whether to use SSL to connect to the LocalStack endpoint, i.e., connect via HTTPS.
• LAMBDA_MOUNT_CODE: Whether to use local Lambda code mounting (via setting __local__ S3 bucket name). Note: may require CDK version <2.14.0 to be fully functional.
• BUCKET_MARKER_LOCAL: Magic S3 bucket name for Lambda mount and hot reloading (default: __local__, will default to hot-reload in a future release)

Deploying a Sample App

The CDK command line ships with a sample app generator to run a quick test for getting started:

$ mkdir /tmp/test; cd /tmp/test
$ cdklocal init sample-app --language=javascript
...

Make sure that LocalStack is installed and started up with the required services:

$ SERVICES=serverless,sqs,sns localstack start

Then deploy the sample app against the local APIs via the cdklocal command line:

$ cdklocal deploy
...
Do you wish to deploy these changes (y/n)? y
...
Stack ARN:
arn:aws:cloudformation:us-east-1:000000000000:stack/TestStack/e3debc0a-311e-4968-8230-ed78f89cb614

Once the deployment is done, you can inspect the created resources via the awslocal command line:

$ awslocal sns list-topics
{
    "Topics": [
        {
            "TopicArn": "arn:aws:sns:us-east-1:000000000000:TestStack-TestTopic339EC197-79F43WWCCS4Z"
        }
    ]
}

Change Log

• 2.18.1: Throw better exception if aws-cdk not found
• 2.18.0: Add support for AWS_ENDPOINT_URL, USE_SSL, and BUCKET_MARKER_LOCAL configurations
• 2.17.0: Fix IPv4 fallback check to prevent IPv6 connection issue with localhost on macOS
• 2.16.0: Add check to prevent IPv6 connection issue with localhost on MacOS
• 2.15.0: Fix issue with undefined BUCKET_NAME_OUTPUT variable; add CI build and eslint config
• 2.14.0: Add switches in patches to accommodate new esbuild packaging mechanism in CDK v2.14.0+
• 1.65.7: Add switch that checks for asset existence before symlinking assets; fix parsing fetched template body for JSON/YAML formats; add missing dependency to "diff" package
• 1.65.6: Create symlinks to Lambda assets to enable persistent code mounting of Lambdas on "cdklocal synth"
• 1.65.5: Add support for LAMBDA_MOUNT_CODE config to enable local Lambda code mounting
• 1.65.4: Add support for large stacks by patching bucketUrl for ToolkitInfo
• 1.65.2: Patch missing getPromise() in forceCredentialRetrieval; remove aws-cdk from npm dependencies
• 1.65.1: Override BucketURL to use path style addressing
• 1.65.0: Initial release

License

The AWS CDK is distributed under the Apache License, Version 2.0.