The CDK Book: The missing Go Code Examples

The CDK Book

The CDK Book “A Comprehensive Guide to the AWS Cloud Development Kit” is a book by Sathyajith Bhat, Matthew Bonig, Matt Coulter, Thorsten Hoeger written end of 2021.

Because the CDK itself is polyglott with jsii, the TypeScript examples are automatically translated in other languages. So the example CDK code used in the book is jsii generated, and there are samples for TypeScript, Python, Java and C#.

If you buy the book from gumroad, you get different versions for Typescript, Python, Java and C#. The content itself is mostly focused on TypeScript, which makes sense, since the CDK is mainly written in TypeScript. A few chapters for Python are also included. The testing part is typescript-only.

What is missing is example content for GO. No problem, we got this covered! We have running examples for almost every chapter.This is a part of my project “Go on AWS”.

Go Samples For the CDK Book

Whenver it is possibly I provide synth-able code snippets, that means cdk synth produces an output. The examples usually do not generate useful code, they are just learning examples.

If the snippets are to small, I provide a readme.

* TCB = The CDK Book * GoA = Go on AWS Webseite

TCB* Chapter 2: What Are Constructs?

• S3 Bucket, CloudFront Distribution

• Construct MySimpleWebsite

TCB Chapter 2.2.3. Level 2 Constructs

• Grant Function

TCB Chapter 2.3.1. The Stack Construct

• Stack

TCP Chapter 4.2.2 Tasks

As an alternative: see Chapter Tools-Task

TCP Chapter 4.2.3 Debugging

Debugging should work out of the box with vscode:

Just start (1) Debugging.

Standard Launch Json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch Package",
            "type": "go",
            "request": "launch",
            "mode": "auto",
            "program": "${fileDirname}"
        }
    ]
}

TCP Chapter 4.2.4 Linting

.. is included in GO.

For formatting run : go fmt *.go

TCP Chapter 5 Project Layout

• For serverless project layout: Chapter Lambda with CDK Overview

• For general project layout: Chapter Exercise CDK-VPC

Notes on files:

• tsconfig.json - not needed with GO

• package.json - the go.mod has almost the same functionality, see Chapter Modules

• .gitignore - the same functionality

• .npmignore - not needed

Tests

• See Chapter Serverless test Pyramid
• See Chapter Unit Test of IAC CDK GO

Directories

• bin/* => main/main.go
• lib/* => files wil be in the project root and subdirs

Projen

As GO does not need so much helper files and handles dependencies better since 1.13, projen is not needed. Please note: projen is not CDK standard project layout.

TCP Chapter 5.1.11. Initializing with the CLI

npx cdk init app --language=go

Shortform

npx cdk init app -l=go

TCP Chapter 6 Custom Resources and CFN Providers

TCP Chapter 6.1.1. Implementing custom resources using AWS CDK

• Sources CDK
• Sources Lambda

TCP Chapter 6.2. CloudFormation Resource Types

• Sources

TCP Chapter 7. Configuration Management

simpleapiwithtestsstack:

• Configuration Management Sources

TCP Chapter 7.1. Configuration Management

DBStack:

• Configuration Management Sources

TCP Chapter 7.1. Static Files

The kind of configuration is different for the several languages.

Here an example for using Systems Manager with paddle “github.com/PaddleHQ/go-aws-ssm” and configuration files with “viper” “github.com/spf13/viper”

The example is a working webserver instance example. Note the readme.md in the source directory

• Configuration with viper and ssm

TCP Chapter 7.3.1. Systems Manager Parameter Store

awsssm.NewStringParameter(stack, aws.String("Parameter"),
    &awsssm.StringParameterProps{
		AllowedPattern: aws.String(".*") ,
        Description:   aws.String("The value Foo"),
        ParameterName: aws.String("FooParameter"),
        StringValue:   aws.String("Foo"),
		Tier: awsssm.ParameterTier_ADVANCED,
    },

TCP Chapter 8.3.1 Docker Image Asset in Action: ECS Fargate

A similar example is in the architecture section

• Go on AWS Chapter Fargate Container

• Source for Fargate Contrainer

• Source Container in ECS pattern

TCP 8.4.1. S3 Assets in Action: Deploying Lambda Functions using S3 Assets

A similar example is in the Lambda Construct section:

• GoA Chapter CDK Lambda Construct
• Source CDK Lambda S3 Asset

TCP 8.5 Docker Bundling

• Source Docker Bundling

• GoA Chapter Docker Bundling

TCP 9 Testing

Most of the concepts are described with code examples in

• GoA Chapter Serverless Test Pyramid
• CDK Infrastructure Testing

See the full source on github.

• Sources

Feedback & discussion

For discussion please contact me on twitter @megaproaktiv

Learn more GO

Want to know more about using GOLANG on AWS? - Learn GO on AWS: here