Introduction

This is a modified version of the spring-petclinic-microservices Spring Boot sample application. Our modifications focus on showcasing the capabilities of Application Signals within a Spring Boot environment. If your interest lies in exploring the broader aspects of the Spring Boot stack, we recommend visiting the original repository at spring-petclinic-microservices.

In the following, we will focus on how customers can set up the current sample application to explore the features of Application Signals.

Disclaimer

This code for sample application is intended for demonstration purposes only. It should not be used in a production environment or in any setting where reliability/security is a concern.

Prerequisite

A Linux or Mac machine with x86-64 (AMD64) architecture is required for building Docker images for the sample application.
Docker is installed and running on the machine.
AWS CLI 2.x is installed. For more information about installing the AWS CLI, see Install or update the latest version of the AWS CLI.
kubectl is installed - https://docs.aws.amazon.com/eks/latest/userguide/install-kubectl.html
eksctl is installed - https://docs.aws.amazon.com/eks/latest/userguide/eksctl.html
jq is installed - https://jqlang.github.io/jq/download/

EKS demo

Build the sample application images and push to ECR

Build container images for each micro-service application

./mvnw clean install -P buildDocker

Create an ECR repo for each micro service and push the images to the relevant repos. Replace the aws account id and the AWS Region.

export ACCOUNT='111122223333'
export REGION='us-east-1'
./push-ecr.sh

Try Application Signals with the sample application

Create an EKS cluster, enable Application Signals, and deploy the sample application to your EKS cluster. Replace new-cluster-name with the name that you want to use for the new cluster. Replace region-name with the same region in previous section "Build the sample application images and push to ECR".

cd scripts/eks/appsignals/one-step && ./setup.sh new-cluster-name region-name

Clean up all the resources. Replace new-cluster-name and region-name with the same values that you use in previous step.

cd scripts/eks/appsignals/one-step && ./cleanup.sh new-cluster-name region-name

Please be aware that this sample application includes a publicly accessible Application Load Balancer (ALB), enabling easy interaction with the application. If you perceive this public ALB as a security risk, consider restricting access by employing security groups.

EC2 Demo

The following instructions describe how to set up the pet clinic sample application on EC2 instances. You can run these steps in your personal AWS account to follow along.

Set up a VPC with a public subnet and a security group accepting all traffic.
Set up 5 EC2 instances all with the following configuration:
- Running on Amazon Linux
- Instance type t2.small or larger
- A key-pair you save to your computer
- Use the VPC, public subnet, and security group created in step 1
- Enable auto-assign public IP
- An IAM instance profile with the following permissions:
  - AmazonDynamoDBFullAccess
  - AmazonKinesisFullAccess
  - AmazonS3FullAccess
  - AmazonSQSFullAccess
Rename your instances as follows to follow along with the instructions:
- setup
- pet-clinic-frontend
- vets
- customers
- visits
Connect to the EC2 instance named setup and start the config, discovery, and admin services in tmux sessions. Feel free to end your connection to the EC2 instance, the tmux sessions will continue running.
- Install java17, git, and tmux as dependencies
```
sudo yum install java-17-amazon-corretto-devel git tmux -y
```
- Verify java 17 is used. If not, run sudo alternatives --config java to change the default java provider
```
java -version
```
- Build the JAR files
```
git clone https://github.com/aws-observability/application-signals-demo.git
cd application-signals-demo/ && ./mvnw clean install
```
- Create an S3 buket in your account and put the created JAR files into it
```
aws s3 mb s3://app-signals-ec2-demo
for dir in `ls -d spring-petclinic-*`; do aws s3 cp $dir/target/*.jar s3://app-signals-ec2-demo; done 
```
- Run config service in a tmux session and then exit by inputting ctrl+b, d.
```
tmux new -s config
cd spring-petclinic-config-server/target/
java -jar spring-petclinic-config...
```
- Run discovery service in a tmux session and then exit by inputting ctrl+b, d.
```
tmux new -s discovery
cd spring-petclinic-discovery-server/target/
java -jar spring-petclinic-discovery...
```
- Run admin service in a tmux session and then exit by inputting ctrl+b, d.
```
tmux new -s admin
cd spring-petclinic-admin-server/target/
java -jar spring-petclinic-admin...
```
Connect to the EC2 instance named pet-clinic-frontend and run the following commands to start the api-gateway service. Feel free to end your connection to the EC2 instance, the tmux sessions will continue running.
- Install java17 and tmux as dependencies
```
sudo yum install java-17-amazon-corretto-devel tmux -y
```
- Verify java 17 is used. If not, run sudo alternatives --config java to change the default java provider
```
java -version
```
- Download jar files from S3 bucket
```
aws s3 sync s3://app-signals-ec2-demo .
```
- Run the sample app in a tmux session and then exit by inputting ctrl+b, d. Make sure to replace the private IP in the export commands.
```
tmux new -s frontend
export CONFIG_SERVER_URL=http://<PRIVATE-IP-OF-SETUP-INSTANCE>:8888
export DISCOVERY_SERVER_URL=http://<PRIVATE-IP-OF-SETUP-INSTANCE>:8761/eureka
java -jar spring-petclinic-api-gateway...
```
Repeat step 5 for the remaining EC2 instances (vets, customers, visits)
Visit the sample application by going to http://<PUBLIC-IPv4-DNS-OF-PET-CLINIC-FRONTEND-INSTANCE>:8080
Interact with the application to ensure you've properly set up the backend services. Note that each service takes a few seconds to come up.

To enable Application Signals on the sample application, please refer to this user guide.

pxaws / application-signals-demo