ECS Service Discovery in Java

Sample project to present the idea of Service Discovery on Amazon Elastic Container Service (ECS). Come and visit our blog for detailed information - Handling Amazon ECS Service Discovery in Java.

The project consists of two SpringBoot applications. If not specified, the instructions below can be used in both cases.

Requirements

• Docker engine (v19 or newer)
• Java v11
• SpringBoot v2.x
• Gradle v6.4.x

How to build it?

The assumption is to run these applications on Amazon ECS, so the projects are packaged into Docker image.

Follow the steps to create Docker image and push it to Elastic Container Registry (ECR).

1. Make sure the Docker is running.
2. Navigate to the app's directory and build the project:

./gradlew clean build

3. Now, package it into Docker image:

docker build -t aws-pattern-match-textapi .

Notice: aws-pattern-match-textapi is just an example name.

4. Log in into ECR:

$(aws ecr get-login --no-include-email --region eu-west-1)

Notice: change the region to reflect your ECS setup

5. Tag the image:

docker tag aws-pattern-match-textprocessor:latest xxxxxxxxxxxx.dkr.ecr.eu-west-1.amazonaws.com/aws-pattern-match-textprocessor:latest

Notice: change the image name and ECR repo in accordance to your setup

6. Push the image:

docker push xxxxxxxxxxxx.dkr.ecr.eu-west-1.amazonaws.com/aws-pattern-match-textprocessor:latest

Notice: change the image name and ECR repo in accordance to your setup

How to run it locally?

Notice: In the commands below, use the images in accordance to your setup.

TextApi

1. Run the image:

docker run --env AWS_REGION=<your-region> --env AWS_DEFAULT_REGION=<your-region> --env AWS_ACCESS_KEY_ID=<your-aws-key-id> --env AWS_SECRET_ACCESS_KEY=<your-aws-key> -d -p 8090:8080 aws-pattern-match-textapi:latest

2. Try it out:

Request:

curl -X POST --header "Content-type: application/json" --header "Accept: application/json" -d '{"text": "somewhere over the rainbow skies are blue, clouds high over the rainbow, makes all your dreams come true"}' http://localhost:8090/textapi

Response:

{
  "language": "en",
  "sentiment": "POSITIVE"
}

TextProcessor

1. Run the image:

docker run --env TEXTAPI_ENDPOINT=http://host.docker.internal:8090 -d -p 8091:8080 aws-pattern-match-textprocessor:latest

Notice: The env variable TEXTAPI_ENDPOINT should point to the TextApi REST endpoint. Change the above command in accordance to your setup.

2. Try it out:

Request:

curl -X POST --header "Content-type: application/json" --header "Accept: application/json" -d '{"text": "somewhere over the rainbow skies are blue, clouds high over the rainbow, makes all your dreams come true"}' http://localhost:8091/textprocessor

Response:

{
  "language": "en",
  "sentiment": "POSITIVE"
}

How to run it on ECS?

Please check our blog post for detailed instructions.

Available tags

1. api-implemented

• both applications expose REST interface
• applications communicate via REST
• the project is working end-to-end

2. sdk-service-discovery

• using AWS Cloud Map SDK for service discovery

3. dns-service-discovery

• using DNS lookup for service discovery