Running Spring Boot apps using AWS Elastic Beanstalk

This repository demonstrates what should be done in order to run Spring Boot apps using AWS Elastic Beanstalk.

In common, nothing special is required on the Java side - if it's necessary to use AWS services, it's necessary to include required dependencies into the pom.xml files.

For example, in this tutorial connectors for AWS SQS and AWS DynamoDB are used so that the following dependencies are added to the pom.xml:

<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>dynamodb</artifactId>
</dependency>
<dependency>
    <groupId>software.amazon.awssdk</groupId>
    <artifactId>sqs</artifactId>
</dependency>

The main magic is happening on the AWS side.

Bird-eye overview

On a very high level, the following app's structure is used:

There are two environment involved:

• Web environment which receives requests from end users on port 80, and
• Worker environment which is not available for end users and processes messages by getting the from the SQS queue.

Both environments are possibly groups of EC2 instances (at least one instance in the group). Every instance hosts a few components:

• Host manager - the component which is responsible for managing Elastic Beanstalk infrastructure on he instance.
• Application itself which processes requests (running on port 5000).
• HTTP proxy (nginx or Apache HTTPd) which receives requests on port 80 and next forwards them to port 5000.

In order worker and web environments have access to DynamoDB table and SQS, first, these resources should be created. Resources should be created using AWS CloudFormation by using the template in aws-resources folder.

This template creates the following resources:

• DynamoDB table with name invoices to store records.
• SQS queue to be a pipeline between web and worker environments.
• IAM roles and EC2 instance profiles to provide environments with access to the resources.

Building Bundles for AWS Elastic Beanstalk

In order to deploy an application's version, it's necessary to upload the version to S3 and make it available for AWS Elastic Beanstalk. In case of Java, app version's bundle may be a plain jar file or a zip file which contains:

• jar or war (in case of Tomcat environment) file.
• env.yaml for configuring the environment.
• cron.yaml for configuring the Cron jobs.
• Any other configuration files in the .ebextenstions folder.

To build these bundles Apache Maven AntRun plugin is used. This plugin is bounded to the package phase and create zip archives with all necessary files inside the dist folder of the app modules.