Microservices

These simple microservices enable us to focus on learning the tools - Docker, Kubernetes, CI, CD and build the infrastructure needed around typical microservices.

Currency Exchange Service

If you ask it the value of 1 USD in BYN the Currency Exchange Service answers

• 1 USD is 2.495 BYN

http://localhost:3000/currency-exchange/from/USD/to/BYN

{
  "id": 10002,
  "from": "USD",
  "to": "BYN",
  "conversionMultiple": 2.495
}

Currency Conversion

Currency Conversion Service is used to convert a bucket of currencies.

• STEP 1 : Currency Conversion Service calls the Currency Exchange Service for the value of 1 USD. It gets a response back saying 2.495.
• STEP 2 : The Currency Conversion Service then multiplies 10 by 60, and returns 24.95 back.

http://localhost:3100/api/currency-conversion/from/EUR/to/BYN/quantity/10

{
  "id": 10002,
  "from": "USD",
  "to": "BYN",
  "conversionMultiple": 2.495,
  "quantity": 10,
  "totalCalculatedAmount": 24.95
}

How does Currency Conversion know the location of Currency Exchange?

• You don't want to HARDCODE
• Configure an Environment Variable - CURRENCY_EXCHANGE_SERVICE_HOST
• --env CURRENCY_EXCHANGE_SERVICE_HOST=http://currency-exchange:3000

Run containers

Build containers without start

docker-compose up --no-start

Start/stop containers

docker-compose start
docker-compose stop