Deploy a Web App on AWS Elastic Beanstalk

In the previous module of this tutorial, you learned that we will be uploading the application in a zip file to S3 using the S3 Assets module in the AWS CDK.

Before that happens, you need to create a zip file of the Node.js application you created in the first module of the tutorial, Build a Web Application, and place it in the root directory of your AWS CDK application under the directory cdk-eb-infra.

If this is the first time you are using AWS CDK in this account, and in this AWS Region, you will need to bootstrap it. When deploying AWS CDK apps into an AWS account and Region, CDK needs to provision resources that it needs to perform deployments. These resources include an Amazon S3 bucket for storing the deployment files, and IAM roles that grant the needed permissions to perform deployments. Provisioning these initial resources is called bootstrapping.

To bootstrap your AWS account and Region, run the following:

This should look something like this:

You can get the account number from the AWS Management Console, and the Region name from this list.

After you have packaged your Node.js application, placed it in the root of your CDK application directory, and bootstrapped your AWS account and Region, you are ready to build and deploy your CDK application.

The first step is to build the CDK application.

If there are no errors in your application, this will succeed. You can now deploy the CDK application in the cloud.

Because we created a new role, you will be asked to confirm changes in your account security level.

Respond with y, and then the deployment will start. It takes a few minutes to complete. When it is done, you will receive a message containing the ARN (Amazon Resource Name) of the CloudFormation stack that this deployment created for you.

If you open the CloudFormation Management console, you will see that there are two new stacks there.

The stack called CdkEbInfraStack contains all the Elastic Beanstalk resources we created in the previous module: Elastic Beanstalk application, application version, instance profile, and environment.

The other stack (with the random string), which was created by Elastic Beanstalk, contains all the resources the Elastic Beanstalk app needs to run—autoscaling groups, instances, Amazon CloudWatch alarms and metrics, load balancers, and security groups.

If you want to see your application deployed in the cloud, the first thing you need to do is find the URL of the web app. You can find this URL by going to the Elastic Beanstalk service in the AWS console, and look for the environment called MyWebAppEnvironment.

Choose the URL to launch the web app.

If you want to make a change to your web app, and you want to redeploy it to the cloud, follow these steps:

• Make the change in the web app
• Package it in an app.zip file
• Place the app.zip file in the root directory of your CDK application
• Build the CDK project - npm run build
• Deploy the CDK project - cdk deploy

Now, you can verify that there is a new version of the Elastic Beanstalk app deployed. If you visit the web app URL, the new version will be deployed. This takes a bit of time; the console will indicate when the new deployment is complete.

If you get the following error when your Node.js application is uploaded to Elastic Beanstalk, you will need to package your application differently.

Remove the package-lock.json and node_modules directory and run this command inside the web app directory.

This will zip the files correctly for Elastic Beanstalk.

You can package your node_modules directory with all your downloaded dependencies in the zip file of your web application.

When you have this directory, Elastic Beanstalk assumes that no dependencies need to be downloaded.

Read more on the instructions on handling Node.js dependencies in Elastic Beanstalk packages.