Introduction to CDK

[phillip-le]

• What is IaaC
• What is CloudFormation
• There are logical IDs which are used by CloudFormation to identify resources uniquely within a stack
• CDK is a higher level of abstraction over CloudFormation letting you write in your chosen language
• CDK is composed of constructs which are higher levels of abstraction over base CloudFormation resources
• Everything is in a CDK app, and then associated with a Stack
• Snapshot testing to check that nothing has changed

import { Template } from 'aws-cdk-lib/assertions';

const template = Template.fromStack(stack);

const result = JSON.stringify(template).replace(
  /"S3Key":"[^"]+"/g,
  '"S3Key":"[REMOVED]"',
);

expect(JSON.parse(result)).toMatchSnapshot();

• Prefer to be overly verbose because infrastructure typically doesn't change
• progress: events is helpful for logging in CI/CD
• Stateless vs Stateful resources
• Changing logical IDs will cause resources to be created and destroyed
• Sometimes you will want to prefer not explicitly setting a name so that CDK can handle cutover of resource creation / deletion under the hood
• Construct trees
• If you're using NodeJsFunction, make sure your CI agent has git and bash

References:

• Don't change logical IDs: https://docs.aws.amazon.com/cdk/v2/guide/identifiers.html#identifiers_logical_ids
• Current set of feature flags: https://github.com/aws/aws-cdk/blob/main/packages/%40aws-cdk/cx-api/FEATURE_FLAGS.md