Wallet gRPC API implementation

A simple wallet gRPC API implementation with Spring Boot and MySQL.

Build and run

Preconditions:

You need to have Docker installed to be able to build and run the application.

Please perform the following steps:

Build an application image

sudo docker build -t=wallet .

Create a docker network

sudo docker network create wallet-net

Start the DB

sudo docker run --name wallet-db \
  -e MYSQL_DATABASE=wallet \
  -e MYSQL_USER=wallet \
  -e MYSQL_PASSWORD=wallet \
  -e MYSQL_ROOT_PASSWORD=wallet \
  --net=wallet-net \
  mysql:5.7.26 

After the DB is running, start the application

sudo docker run --name=wallet-app \
  --net=wallet-net \
  -p 6565:6565 \
  wallet:latest

After the application has started the API is accessible on port 6565 of your local machine. Check the API definition to be able to perform gRPC requests.

Note: I tested the build only on a Linux machine. The commands should also work on Mac (sudo is not required).

Technologies and solutions I used

I used the technology stack declared in the specification, in particular:

• Java 8+ (I used 11)
• Spring 5.x
• gRPC
• MySQL 5.x
• Gradle
• JUnit
• Docker
• Hibernate
• Spring Boot 2.x

Apart from the required technologies, I took LogNet gRPC Spring Boot Starter as a gRPC implementation because it fits well with Spring Boot. I also used Flyway DB migration library because it is simple, reliable and compatible with Spring Boot.

Performance estimations

I didn't make performance estimations because of limited time.

What could be done better

1. Error handling in the API could be improved.
2. WalletController
   could be covered with tests.