Whenever we need a cloud based deployment with handful of resources we go for manual deployment. But what if the resources needed are large enough to be deployed manually ? In this case we consider programmatically deployment using cdk.
As the complexity of the system increases , the needed infrastructure also grows , so managing it manually becomes little tough. So today we will witness as how to use AWS development kit to deploy a sample app in cloud.
What is AWS CDK ?
The AWS Cloud Development Kit is an open-source software development framework to define cloud infrastructure in code and provision it through AWS Cloud Formation. It enables us to model application infrastructure using Python , JAVA , .NET etc.
The above diagram shows the infra workflow of the AWS CDK.
The AWS CDK is available in following languages.
- JAVA
- .NET
- GO
- PYTHON
- Javascript or typescript.
Installing AWS CDK In your system.
To install AWS CDK we will use npm to install in our system.
The below command is used to install the kit.
sudo npm install -g aws-cdkThe above command will give the following output.
After this to check the version just type the below command to know the version.
cdk version
2.20.0 (build 738ef49)So once the cdk is installed lets move to deploy a sample project using aws cdk.
Deploying a sample application using cdk.
We will go step wise to set up the aws cdk.
1 – Initialize AWS CDK project.
The aws cdk gives a simple command to initialize an application in the language of users choice. The below command will set and initialize an application.
cdk init sample-app --language=typescriptTHe above command sets a module that contains its own set of dependencies. The above command creates a typescript CDK application with the sample app template.
Lets see the output of the above command.
So after the command is run the initialization starts and it sets the particular folder to initial typescript project. The main file that we need to deal with is the cdk-stack.ts file in the lib folder. This file contains a single stack with constructs in it.
THe below code shows the file code.
import { Duration, Stack, StackProps } from 'aws-cdk-lib';
import * as sns from 'aws-cdk-lib/aws-sns';
import * as subs from 'aws-cdk-lib/aws-sns-subscriptions';
import * as sqs from 'aws-cdk-lib/aws-sqs';
import { Construct } from 'constructs';
export class AwsCdkStack extends Stack {
constructor(scope: Construct, id: string, props?: StackProps) {
super(scope, id, props);
const queue = new sqs.Queue(this, 'AwsCdkQueue', {
visibilityTimeout: Duration.seconds(300)
});
const topic = new sns.Topic(this, 'AwsCdkTopic');
topic.addSubscription(new subs.SqsSubscription(queue));
}
}
The ckd init command produces few files in the particular directory.
- It produces .gitignore file that and initializes it as a git repo.
- package.json -> It manages the project dependencies and a tsconfig.json file for Typescript configuration.
While initializing it also gives few commands which show us what when to use. Like to compile the app for catching errors we can use
npm run build2 – Synthesize the application to cloud formation template.
The synth command helps to synthesize the stack to an AWS CloudFormation template.
The below command helps to atain the above
cdk synth
The output is like :-
Resources:
AwsCdkQueue7B79C8BE:
Type: AWS::SQS::Queue
Properties:
VisibilityTimeout: 300
UpdateReplacePolicy: Delete
DeletionPolicy: Delete
Metadata:
aws:cdk:path: AwsCdkStack/AwsCdkQueue/Resource
AwsCdkQueuePolicy4B641FDF:
Type: AWS::SQS::QueuePolicy
Properties:
PolicyDocument:
Statement:
- Action: sqs:SendMessage
Condition:
ArnEquals:
aws:SourceArn:
Ref: AwsCdkTopicF164620F
Effect: Allow
Principal:
Service: sns.amazonaws.com
Resource:
Fn::GetAtt:
- AwsCdkQueue7B79C8BE
- Arn
Version: "2012-10-17"
Queues:
- Ref: AwsCdkQueue7B79C8BE
Metadata:
aws:cdk:path: AwsCdkStack/AwsCdkQueue/Policy/Resource
AwsCdkQueueAwsCdkStackAwsCdkTopic9A093C2831483039:
Type: AWS::SNS::Subscription
Properties:
Protocol: sqs
TopicArn:
Ref: AwsCdkTopicF164620F
Endpoint:
Fn::GetAtt:
- AwsCdkQueue7B79C8BE
- Arn
Metadata:
aws:cdk:path: AwsCdkStack/AwsCdkQueue/AwsCdkStackAwsCdkTopic9A093C28/Resource
AwsCdkTopicF164620F:
Type: AWS::SNS::Topic
Metadata:
aws:cdk:path: AwsCdkStack/AwsCdkTopic/Resource
CDKMetadata:
Type: AWS::CDK::Metadata
Properties:
Analytics: v2:deflate64:H4sIAAAAAAAA/1WNQQ7CIBBFz9I9HUvjxnUvoK170wIm01aoDGgM4e4WSEzczP//5SXTQttAU41vqoVc6hUnCIMbxcJ2dAv0JAgXr7xi3V2Xku/ZrCg+P1hmZKR3f/ATCYubQ6OT8bevZkORaC4xptorMt6K/KMzWmIyI9NGKpjp8OJH4Cfg1UyItfXa4UNBX/ILmxlUMcEAAAA=
Metadata:
aws:cdk:path: AwsCdkStack/CDKMetadata/Default
Condition: CDKMetadataAvailable
Conditions:
CDKMetadataAvailable:
Fn::Or:
- Fn::Or:
- Fn::Equals:
- Ref: AWS::Region
- af-south-1
- Fn::Equals:
- Ref: AWS::Region
- ap-east-1
- Fn::Equals:
- Ref: AWS::Region
- ap-northeast-1
- Fn::Equals:
- Ref: AWS::Region
- ap-northeast-2
- Fn::Equals:
- Ref: AWS::Region
- ap-south-1
- Fn::Equals:
- Ref: AWS::Region
- ap-southeast-1
- Fn::Equals:
- Ref: AWS::Region
- ap-southeast-2
- Fn::Equals:
- Ref: AWS::Region
- ca-central-1
- Fn::Equals:
- Ref: AWS::Region
- cn-north-1
- Fn::Equals:
- Ref: AWS::Region
- cn-northwest-1
- Fn::Or:
- Fn::Equals:
- Ref: AWS::Region
- eu-central-1
- Fn::Equals:
- Ref: AWS::Region
- eu-north-1
- Fn::Equals:
- Ref: AWS::Region
- eu-south-1
- Fn::Equals:
- Ref: AWS::Region
- eu-west-1
- Fn::Equals:
- Ref: AWS::Region
- eu-west-2
- Fn::Equals:
- Ref: AWS::Region
- eu-west-3
- Fn::Equals:
- Ref: AWS::Region
- me-south-1
- Fn::Equals:
- Ref: AWS::Region
- sa-east-1
- Fn::Equals:
- Ref: AWS::Region
- us-east-1
- Fn::Equals:
- Ref: AWS::Region
- us-east-2
- Fn::Or:
- Fn::Equals:
- Ref: AWS::Region
- us-west-1
- Fn::Equals:
- Ref: AWS::Region
- us-west-2
Parameters:
BootstrapVersion:
Type: AWS::SSM::Parameter::Value<String>
Default: /cdk-bootstrap/hnb659fds/version
Description: Version of the CDK Bootstrap resources in this environment, automatically retrieved from SSM Parameter Store. [cdk:skip]
Rules:
CheckBootstrapVersion:
Assertions:
- Assert:
Fn::Not:
- Fn::Contains:
- - "1"
- "2"
- "3"
- "4"
- "5"
- Ref: BootstrapVersion
AssertDescription: CDK bootstrap stack version 6 required. Please run 'cdk bootstrap' with a recent version of the CDK CLI.The above is generated in cdk.out file which is the cloud formation template and the file can be deployed either manaully or by using the terminal or command line. The CDK toolkit also supports the deployment . Now lets move towards the deployment using the commandline.
3 – How to deploy the above stack
Prerequisite : Before deploying the below are the mentioned requisite.
- AWS cli installed
- Aws credentials configured in your system.
Now to deploy the stack using the above
To deploy the stack we need to run the below command
cdk deploy
The above image shows the deployment .
So these were the very simple steps of how to deploy an application using programmatically using cloud formation template.
Conclusion.
The above article provided a quick overview as how to proceed for programmatic deployment of stack. Also there is manual deployment that simply involves uploading the cloud formation template in the aws.
