octank-tax-calc

Bare-bones Spring Boot microservice used for demo purposes. Not supported - no warranty explicit or implied.

This solution leverages:

• Spring Boot 2.2.4.RELEASE
• Java 1.8
• JBoss Wildfly 18.0.1.Final (Formerly JBoss Application Server)

API accepts cart item data with subtotal and returns tax rate and total tax.

Example cart data POST input:

{
    "cartId": "TestUserCart",
    "productId": "10001",
    "quantity": "5",
    "subtotal": "108.11"
}

Example API response:

{
    "responseObject": {
        "totalTax": "6.648765",
        "taxRate": "0.0615"
    }
}

Pre-requisites

• Install Maven and Java 8
• Install and configure AWS CLI
• Clone repo
• Update <aws-account-number> with your real AWS account number in the deploy steps below and in ./deploy/kubernetes/ecr-login.sh. Change the AWS region throughout if desired.

Examples

Sample curl POST script:

curl -w "\n" \
   -H "Accept: application/json" \
   -H "Content-Type:application/json" \
   -X POST \
   --data '{"cartId": "TestUserCart", "productId": "10001", "quantity": "5", "subtotal": "108.11"}' \
   "http://localhost:8080/tax-calc/"

Generate Load

To generate load, you can run a GET instead of a POST. This will run Pi calculations to simulate processing time and will return randomized taxRate and totalTax in JSON format:

{
    "responseObject": {
        "taxRate": "0.0807",
        "totalTax": "86.22"
    }
}

Load generation script:

• Place the script below in a file called tax-calc-generate-load.sh.
• Call the script with a single argument that defines how many times to call the service: ./tax-calc-generate-load.sh 1000

#!/bin/bash

if [ $# -eq 0 ]
then
   echo "Error: You must provide an interger in position 1 to indicate the number of calls the script should make to the tax-calc service."
   exit
fi

x=0;
while [ $x -le $1 ];
do
   curl -w "\n" http://tax:8080/tax-calc/ &
   echo "  ";
   x=$(( $x + 1 ));
done

Deployment

Run locally via Maven

• From project root, run: ./mvnw spring-boot:run
• Navigate to: http://localhost:8080/tax-calc/

Build Docker container

• From project root, run: ./mvnw clean package && docker build --tag=tax-calc .

Run locally via Docker with Wildfly

• Run: docker run -it -p 8080:8080 tax-calc
• Navigate to: http://localhost:8080/tax-calc/

Deploy to Kubernetes with Wildfly

• Push image to ECR:
  $(aws ecr get-login --no-include-email --region us-east-2)
docker tag tax-calc:latest <aws-account-number>.dkr.ecr.us-east-2.amazonaws.com/tax-calc:latest
docker push <aws-account-number>.dkr.ecr.us-east-2.amazonaws.com/tax-calc:latest
• Deploy to K8s cluster:
  ./deploy/kubernetes/ecr-login.sh
kubectl apply -f deploy/kubernetes/kube-deploy.yaml
• Navigate to: http://localhost:30001/tax-calc/

Run X-Ray daemon locally for development:

cd deploy/xray-local
docker build -t xray-daemon .
docker run \
      --attach STDOUT \
      -v ~/.aws/:/root/.aws/:ro \
      -e AWS_REGION=us-east-2 \
      --name xray-daemon \
      -p 2000:2000/udp \
      -p 2000:2000/tcp \
      xray-daemon -o

Deploy X-Ray daemon image to ECR

• Push image to ECR:
  $(aws ecr get-login --no-include-email --region us-east-2)
docker tag xray-daemon:latest <aws-account-number>.dkr.ecr.us-east-2.amazonaws.com/xray-daemon:latest
docker push <aws-account-number>.dkr.ecr.us-east-2.amazonaws.com/xray-daemon:latest