CDK stands for Cloud Development Kit. It defines cloud infrastructure in code and provisions resources through AWS CloudFormation.
This post will demonstrate how to setup and execute a simple CDK application to create a AWS S3 Static Website.
- Node.js >= 10.3.0
- Python 3
- configured AWS CLI with read/write access to S3 service
Install AWS CDK
First install CDK:
npm install -g aws-cdk pip install --upgrade aws-cdk.core
Setup CDK Application
Execute the following commands to initialize the CDK application:
mkdir cdk-s3-website cd cdk-s3-website cdk init --language python source .env/bin/activate pip install -r requirements.txt
After successfully setup the CDK application, let’s take a look at some files of interest:
This is the code execution of the application:
from aws_cdk import core from cdk_s3_website.cdk_s3_website_stack import CdkS3WebsiteStack app = core.App() CdkS3WebsiteStack(app, "cdk-s3-website") app.synth()
It invokes the custom generated class CdkS3WebsiteStack to create the needed resources.
from aws_cdk import core class CdkS3WebsiteStack(core.Stack): def __init__(self, scope: core.Construct, id: str, **kwargs) -> None: super().__init__(scope, id, **kwargs) # The code that defines your stack goes here
This is where the infrastructure as code will be implemented. Currently, it is just an empty class.
This is where we put additional packages needed here.
Build a S3 static website infrastructure
So let’s start filling in the blanks to create the website infrastructure. Since we are using S3 service, we need the aws-s3 package. Append the following line to requirements.txt:
Then run the following commands again:
pip install -r requirements.txt pip install --upgrade aws-cdk.core
Modify cdk_s3_website_stack.py as follow:
from aws_cdk import (core, aws_s3 as _s3) class CdkS3WebsiteStack(core.Stack): def __init__(self, scope: core.Construct, id: str, **kwargs) -> None: super().__init__(scope, id, **kwargs) # The code that defines your stack goes here bucket = _s3.Bucket(self, id + "_s3-bucket", bucket_name= ('cdk-s3-static-website'), website_index_document= 'index.html', website_error_document= 'error.html', public_read_access= True, removal_policy= core.RemovalPolicy.DESTROY)
This will create a bucket called cdk-s3-static-website using index.html as the index document. Setting public_read_access to True will automatically setup the required bucket policy for public access.
Note that the removal policy is set to DESTROY. That means we want the S3 bucket to be destroyed when we delete the CDK infrastructure. However, please note that the bucket will NOT be destroyed if it is not empty.
Now try to run command cdk synth. If everything is setup correctly, this command will display the corresponding CloudFormation template needed to create and setup the S3 bucket.
Time to run the following command to deploy the infrastructure:
Review the resource to be created and enter ‘y’ to confirm the deployment.
Success. The S3 bucket should be created. We can verify it by checking at the AWS management console.
You can see the bucket is publicly accessible and the bucket policy is setup correctly. What’s left to do is to upload index.html and you have a working website.
To clean up the infrastructure, run the command cdk destroy
That’s it. You now have a working CDK application.