CloudFormation Example for API Gateway With Lambda and a Redis Cluster in Your VPC

What?

This template tries to demonstrate a complete microservice that uses AWS services to create a simple serverless API. It uses CloudFormation to create the following and relate all of them to one another as needed:

• API Gateway
  • API Resource (one)
  • API Methods (GET / POST)
• Lambda Function
  • This is what implements the logic for the service, and the code for the function is also part of this repo.
• Redis ElastiCache Cluster
  • Configured to be used by the Lambda function.
  • This runs in your VPC (because it's accessed via a port on your network, AWS requires this)
• IAM Roles and Policies
  • So that the API can invoke the function and the function has access to necessary resources.

Why?

Because it can be really tough getting all of this set up on your own. There are a number of examples of individual pieces, but I couldn't find examples of how to wire all of them together.

The goal of this repo is that you can have a single repo that contains the Lambda code for the service, as well as the configuration for provisioning the service. The hope is that you could add automated unit testing, and if that passed, the same repo could build your dev environment, potentially run integration tests, and then either automatically or manually deploy the API. Automating all of this will greatly simplify things if your desire is to build self-contained serverless microservices.

How to Use It

1. Install custom resources for API creation via CloudFront
   • We use Carl Nordenfelt's great custom resources for making the API resources in AWS CloudFormation since CFN doesn't actually support them natively yet. To get started with it, please install them as described in his documentation: https://apigatewaycloudformation.bynordenfelt.com/. I built this using the latest version at the time: 1.5.0 (2016-04-10).
2. Copy cloudformation/sample-params.json to cloudformation/api-params.json.
3. Edit cloudformation/api-params.json to fill in your own values.
4. Run the following command:

aws cloudformation create-stack --stack-name <YOURSTACKNAME-CAN-BE-ANYTHING> \
    --template-body file://./cloudformation/complete-api.template \
    --parameters=file://./cloudformation/api-params.json \
    --capabilities CAPABILITY_IAM

If you want to monitor the status of your stack creation on the CLI, you can use this command:

aws cloudformation describe-stacks --query='Stacks[*].{ Name: StackName, Status: StackStatus }'

License

This software is released under the MIT license. See the license file for more details.

Feel free to take the template and modify it for your own use.

Contributing

At this point I don't have my normal jshint, jscs, Travis CI stack integrated in this repo. I also don't have unit testing - something I hope to add in the future. So, I don't have a way you can automatically validate your contributions. That said, if you want to contribute, please submit a pull request, but only after doing the following:

1. Make sure your code follows the coding standards that are in the file(s) you are editing (e.g. three space indentation, never a tab, never trailing whitespace).
2. (Obviously) Run your code and make sure that you can actually build a working stack with it.