Currency Converter

A currency conversion application built with Spring Boot and deployed to EC2

1. Deployment details

Service	Address
Spring Boot App	http://44.193.212.220:8080
Prometheus	http://44.193.212.220:9090
Grafana	http://44.193.212.220:3000

2. Requirements checklist

Requirement	Status	Additional comments
Basic UI	✅	Deployment URL - http://44.193.212.220:8080
REST endpoint with source, target, amount as params	✅	Example - /api/convert?source=EUR&target=USD&amount=100
Leverage ExchangeRates API	✅	https://exchangeratesapi.io/
Validation of input	✅	Validation Service
Unit & Integration Tests	✅	Tests
Cache responses from https://exchangerates.io	✅	Used Caffeine with TTL of 1 min
Format result using Web i18n	✅	Class Method
Server-Timing header in response	✅	ServerTimingAdvice.java
CSRF and CSP	✅	Configuration
Deployed to EC2	✅	http://44.193.212.220:8080
Add instrumentation and forward to Grafana	✅	Dashboard ID: admin Password: admin

3. API Contract

API Request

http://44.193.212.220:8080/api/convert?source=eur&target=usd&amount=100.100

Request Params

Param	Description
source	Currency to be converted from
target	Currency to be converted to
amount	Amount of currency to be converted

API Response

Plain text response Example - $118.17205399999999

Error Codes

Code	Description
400	Invalid source, target or amount
503	Unable to fetch rates from third-party service for the given request params

Note: Common currencies like USD, INR not supported as source by Exchange Rates service in Free tier

4. Run project locally

4.1 Quick run from Docker Hub

docker run -p 8080:8080 hiscodesmells/nosto-currency-converter:latest

Note: This command only runs the Spring Boot application

4.2 Complete setup (Spring Boot + Prometheus + Grafana)

git clone https://github.com/hiscodesmells/currency-converter.git
cd currency-converter
docker-compose up

Service	Address
Spring Boot App	http://localhost:8080
Prometheus	http://localhost:9090
Grafana Dashboard	http://localhost:3000