NLB and ECS Service with CDK
The AWS CDK is a framework for modeling cloud infrastructure as reusable components and then provisioning through declarative AWS CloudFormation. It supports multiple languages. It orchestrates the building of cloudformation stacks.
AWS CDK Architecture
ApplicationExecutable programs and is used to render and deploy CFN templatesStack(s)Deployable units and it knows about region and accountConstruct(s)Representations of AWS resources and can form a hierarchical tree structure
Advantages with AWS-CDK based code
- CDK is a developer-friendly version of Cloud Formation
- Apply software development best practices to infrastructure management
- With AWS CDK we can write less code
- Easy to share and reuse your infrastructure as a library
- Easy to use logic (if statements, for-loops, etc.) to define your infrastructure
- Easy to integrate with the code review workflow
- Code completion within your IDE
- Easy to integrate with our CI/CD process
AWS CDK Example : NLB based ECS Fargate Service
With a sample example in github, check out the CDK Install and configure it. Then check out the fargate-service-nlb example from github and follow the steps from readme.
AWS local configurations for CDK
$ aws configureInstall aws-cdk
$ npm install -g aws-cdkInitialize the CDK
$ mkdir fargate-service-nlb && cd fargate-service-nlb$ cdk init --language=typescript
Build code
$ npm run buildSynthesize the cloud formation template code
$ cdk synthDeploy the Infra on AWS
$ cdk deployTo Run the Service Deployed
Create an API Gateway manually to test the service which is avialable via NLB through the VPC link integration. (See below screen shots)
Destroy and cleanup
$ aws cloudformation delete-stack --stack-name search-api-serviceImplementation Summary
AWS VPC , Role and Permissions
ECS Cluster (Fargate type), Task Definition with Container from ECR, Log Group Def
Network Load Balancer (NLB) , Security Group , and ECS Fargate Service
Target group and application to call the Stack and in turn it calls constructs
CDK Deployment on AWS (Check)
An APIGateway with VPCLink created manually to test the NLB based ECS Service (fargate)
Conclusion
- The AWS CDK is a powerful tool that gives the developers the flexibility and ease of maintaining the application’s infrastructure code as they would any other application’s code. By simply abstracting the markup or declarative template files into readable code.
- When our CDK based PoC was ready and it was a pretty good learning experience. Having said that, there are always some flaws, like debugging the code for some time because there was a new release with breaking changes, but it’s natural for a tool under heavy development.
- Cloudformation template from the synth is still easily readable by a human. One can take the cloudformation template and edit it.
- When you are doing the IaaC try with the CloudFormation, see how it works out, then try to convert it into AWS CDK. You will be best judge to decide whether you would want continue with CloudFormation or shift to either AWS cDK or tools such as Terraform.
One thing to note is there is no one thing fits all , it all depends on your requirements, team, project and your company.
Where can you start ?
