Wallet Service

Summary

Is a simple service created as a test task for golang developer position.

It allows to create user accounts and carry out payments transfering money between accounts.

Task Requirements

Use go-kit to build a service.

Use specified entities:

• Account:

    id: bob123 
    balance: 100.00 
    currency: USD
  

• Payments:

    account: bob123 
    amount: 100.00 
    to_account: alice456 
    direction: outgoing 
  
    account: alice456 
    amount: 100.00 
    from_account: bob123 
    direction: incoming 
  

User stories

• Send a payment from one account to another
• See all payments
• List accounts

Added stories:

• Create new account

Limitations

Payments between accounts in different currencies not supported.

Also there are lots of things to do, but they were not done because of lack of time.

Documentation

Building

Just an ordinary go building process:

go get ./...
go install github.com/shirolimit/wallet-service/cmd/wallet_service

Usage

API documentation can be found in api.md and openapi.yaml.

Use the following command to run service after building:

wallet_service --connection-string=<postgres_connection_string> --http-address=":8080"

Docker

Go to the project dir and build container:

docker build -t wallet-service .

Run container (specify correct connection string):

docker run -d -p 8080:8080 --env CONNECTION_STRING="user=wallet dbname=wallet_service host=127.0.0.1 password=123456 sslmode=disable" wallet-service

TODO

Add some instrumentation:

• tracing (i.e. Zipkin)
• metrics (i.e. Prometheus)
• throttling
• circuit breaker
• etc.

Add compose script.

Improve test coverage (endpoints, transports and middlewares are not covered at all).

Widen entities: add payment timestamps, allow currency exchange