GraphQL Kafka API Payment System

A backend API service for a payments wallet.

Users can create account (includes an initial amount), transfer funds to another user's account and view their transaction history.

This is a technical Assessment project. This solution uses Node.js runtime, GraphQL for the API layer, Redis for user sessions, MongoDB for the database, Kafka for transaction events.

GraphQL Resolvers

Resolvers	Description
account	Gets authenticated user account information.
balance	Gets authenticated user account balance.
transactions	Gets authenticated user transaction history.
login	Logs in and authenticates users.
createAccount	Registers and authenticates users.
transfer	Transferring of funds to other user's account.

Requirements

Before getting started, make sure you have the following requirements:

• Docker
• Docker Compose (Supporting compose file version 3)
• A bash compatible shell

Run The Project

Follow these steps to get your development environment set up:

1. Clone this repository locally;

# Change to the desired directory
$ cd <desired-directory>

# Clone the repo
$ git clone https://github.com/evanigwilo/graphql-kafka-payment-system.git

# Change to the project directory
$ cd graphql-kafka-payment-system

2. Change environmental variables filename from .env.example to .env

3. Update the .env file values for the following variables:

# Kafka configurations
KAFKA_SERVER=
KAFKA_CLUSTER_API_KEY=
KAFKA_CLUSTER_API_SECRET=

4. At the root directory, run the following command:

# Create external docker volume for the mongo database
$ docker volume create mongo-db-volume

# Build and run the server in a container environment
$ docker-compose --env-file .env -p payment-system-stack -f docker-compose.yml up --build -d

5. The api-server will be running at http://localhost:4000/v1

Useful commands

# Stops and removes containers, networks and volumes
$ docker-compose --env-file .env -p payment-system-stack -f docker-compose.yml down -v --remove-orphans

References

Confluent Docs