Currency-Exchange Service

Currency exchange is Java based web application using latest version of spring boot, jpa, hibernate, mysql. Main aim of this web service is to convert provided amount in the API from the world popular currencies into indian rupee. Majorly 5 currencies are being converted into INR, in this project. We will insert the conversion value from these currencies to INR into the database and when we hit the currency-exchange api with the amount, it will convert that amount of currency into INR. Ex. for amount entered 1, all the corresponding currency values are converted into INR.

1. USD: American dollar => 1USD = ₹82
2. EUR: Euro=> 1 EUR = ₹89
3. AUD: Australian dollar => 1 AUD = ₹55
4. GBP: Pound => 1GBP = ₹103
5. KWD: Kuwaiti Dinar => 1KWD = ₹267

URLs

Repository Link:

GitHub link of the source code is here.

Docker images:

Docker hub link of all the images created is here.

Endpoints

1. Test URL (If everything is working fine): GET http://34.170.27.49:8291/test Response Body:

   Currency Exchange service is working fine
   

2. Exchange rate DB insertion API: POST http://34.170.27.49:8291/currency-exchange Request Body:

   [
     {
      "from": "USD",
      "to": "INR",
      "conversionMultiple": 82
    },
    {
      "from": "EUR",
      "to": "INR",
      "conversionMultiple": 89
    },
    {
      "from": "AUD",
      "to": "INR",
      "conversionMultiple": 267
    },
    {
      "from": "GBP",
      "to": "INR",
      "conversionMultiple": 103
    },
    {
      "from": "KWD",
      "to": "INR",
     "conversionMultiple": 267
    }
   ]

3. Requesting conversion values for amount input: GET http://34.170.27.49:8291/currency-exchange/indian-rupee/for/20 Response Body:

   {
    "id": 1,
    "to": "INR",
    "from": "USD-EUR-AUD-GBP-KWD",
    "conversionMultiple": 1.0,
    "inputValue": 20,
    "usdToInrValue": 1640.00,
    "eurToInrValue": 1780.00,
    "audToInrValue": 5340.00,
    "gbpToInrValue": 2060.00,
    "kwdToInrValue": 5340.00
   }

DOCKER

Docker images can be created in two ways:

1. Adding the docker plugin details in the pom.xml file and maven build the project. Add this line below maven plugin

   <configuration>
      <image>
        <name>devanurag/${project.artifactId}:${project.version}</name>
      </image>
      <pullPolicy>IF_NOT_PRESENT</pullPolicy>
   </configuration>

   Here devanurag is the docker hub username. Then run this command in maven build… of eclipse

   spring-boot:build-image -DskipTests

   This will create the docker image with the name devanurag/currency-exchange: For reference adding link for maven commands: https://jenkov.com/tutorials/maven/maven-commands.html For first time building the project use mvn package command in the terminal.

2. Another way using the command line by creating the docker image from the jar file as mentioned in Dockerfile

   docker build -t currency-exchange:<TAG> .

   -t is for tagging the image. currency-exchange is the name of the image. TAG is the tag you want to add to that image. If you don’t add any tag, it defaults to the tag named latest. . means, we are referring to the Dockerfile location as the docker build context.

For running the docker image generated

docker run -p 8291:8291 currency-exchange:<TAG>

Check if you are logged in, if not logged in, it will ask for username and password

docker login

Change the docker tag before pushing, add docker username (hub.docker.com) in front of the image. It will push the image to that username account.

docker tag currency-exchange:<TAG> devanurag/currency-exchange:<TAG>

Push the docker image to docker hub

docker push devanurag/currency-exchange:<TAG>

Run the docker using docker compose file

docker-compose up

List all the running containers

docker container ls
OR
docker ps

Remove all unused containers, networks, images

docker system prune

KUBERNETES

We are running kubernetes on the GKE free version. Create the cluster on GKE and run the following commands in the GKE console.

For applying the secret

kubectl apply -f mysqldb-secret.yaml

To check the secret is successfully applied

kubectl get secret

For applying the configmap

kubectl apply -f mysqldb-configmap.yaml

To check the configmap is successfully applied

kubectl get configmap

For applying the storage class and persistent volume claim

kubectl apply -f mysqldb-storage.yaml

For checking the pvc

kubectl get pvc

Now, applying the mysql database deployment

kubectl apply -f mysqldb-deployment.yaml

To check if the mysql server is running

kubectl exec -it <mysql-pod-name> --bash
bash-4.4# mysql currency_exchange_db -u root -p

If mysql server is running login using the credentials, you will be logged in

bash-4.4# mysql currency_exchange_db -u root -p

Let's get the port number and more information about mysql pod

kubectl describe pod <mysql-pod-name>

To check if the mysql service is running, on what type, IP address and Port:

kubectl get service
OR
kubectl describe service <mysql-service-name>

Now, let's deploy the currency exchange service

kubectl apply -f currency-exchange-deployment.yaml

Keep on checking with the pod, what's happening

kubectl get pod <pod-name> --watch

Check the logs for the pod

kubectl logs --tail=-1 <pod-name>

Get all the deployments

kubectl get deploy

For deleting the deployment

kubectl delete deploy <deployment-name>

For deleting the service

kubectl delete service <service-name>

For deleting everything (pods, deployments, containers, services)

kubectl delete all --all

For removing all the files locally from GKE

rm *

References

1. https://openliberty.io/guides/kubernetes-intro.html#tearing-down-the-environment
2. https://dev.to/musolemasu/deploy-a-mysql-database-server-in-kubernetes-static-dpc
3. https://www.kindsonthegenius.com/deploy-springboot-with-mysql-to-kubernetes-minikube-step-by-step-tutorial/
4. https://github.com/Java-Techie-jt/springboot-crud-k8s
5. https://loft.sh/blog/kubernetes-persistent-volumes-examples-and-best-practices/
6. https://medium.com/globant/kubernetes-deployment-deploying-mysql-databases-on-the-gke-8fa675d3d8a
7. https://www.youtube.com/watch?v=qmDzcu5uY1I
8. https://medium.com/@dayan888/sample-java-web-system-on-kubernetes-e52069390916

sql query to insert dummy data into the database

   insert into currency_exchange (conversion_id, conversion_value, conversion_from, conversion_to) values(1001, 82, 'USD', 'INR');
   insert into currency_exchange (conversion_id, conversion_value, conversion_from, conversion_to) values(1002, 89, 'EUR', 'INR');
   insert into currency_exchange (conversion_id, conversion_value, conversion_from, conversion_to) values(1003, 55, 'AUD', 'INR');
   insert into currency_exchange (conversion_id, conversion_value, conversion_from, conversion_to) values(1004, 103, 'GBP', 'INR');
   insert into currency_exchange (conversion_id, conversion_value, conversion_from, conversion_to) values(1005, 267, 'KWD', 'INR');

License

MIT