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Create a CDK

Introduction​

CDKs are Octo definition files that define various Octo components, such as models, resources, modules, etc. They are generally created by developers with DevOps background, targeting a specific cloud provider.

A CDK exposes one or more modules with logic to encapsulate and define parts of a cloud infrastructure, conforming to a specific standard. End users can then ingest these CDKs to create real cloud infrastructure using the exposed modules.

CDKs are written in TypeScript, and you can create one from scratch!
However, that requires setting up various tools, such as tsconfig.json, eslint, and compilers. To make things easier, Octo provides pre-configured TypeScript templates for CDKs.

Creating a CDK​

To create a new CDK, simply run the below command.

npx @quadnix/octo-build create-cdk -n test-cdk -p .

For beginners, you can also create a new CDK with a pre-configured example.

npx @quadnix/octo-build create-cdk -n test-cdk -p . -o withExamples=true

Running either command will set up a new TypeScript project with,

  • a pre-configured tsconfig.json file.
  • a pre-configured eslint configuration.
  • a pre-configured prettier configuration.
  • Jest, circular-dependency detector, and Types.

Running with option withExamples=true will also add a few example components for demonstration and to ensure that the CDK can be run successfully.

This should create a directory structure like this: Octo CDK Structure

tip

Octo generates new CDKs with a pretty stringent set of eslint and tsconfig rules. But if these rules are not to your liking, you can override/modify them accordingly. Please see eslint and tsconfig official documentation for more information.

CDK Dummy Example​

The dummy example provided in the CDK is a perfect starting point to be able to see Octo in action without worrying about manipulating a real cloud infrastructure - because the dummy example just simulates making a few REST API calls for demonstration purposes.

It defines a new dummy-app module to create a new App model with an anchor. It then defines a new resource to make a REST api call and collect the response. Finally, it defines model and resource actions as per Octo's convention.

We encourage you to study the directory structure, and get familiar with the various Octo components defined here. In coming sections, we will explore each of these components in detail.

Validating CDK​

Your CDK is a library to be published and consumed by you or other developers in their infrastructure. But before you publish, you need to validate your components will work as expected. Octo provides a built-in testing framework for this.

A sample test is included in the dummy example. To run tests, simply run the below command.

npm test

Summary​

In this section we introduced how to create a new CDK, with and without examples. We also discussed the importance of testing, and introduced you to Octo's built-in testing framework. Next, we will dive deep into each of the Octo components, and explore how they are created.