ThesisMicroserviceTemplate

A microservice template, written as part of a master's thesis. The template implements a simple user data service that saves personal data in key-value pairs.

Dependencies

All direct dependencies and their justifications are listed below.

General

• @prisma/client: type-safe query builder generation
• express: the web framework for handling REST requests
• jsonwebtoken: implementation of the JWT standard's functions
• prisma: database tools, including code generation and migration

Development

• @types packages: TypeScript type declarations for JavaScript packages
  • @types/express
  • @types/jest
  • @types/jsonwebtoken
  • @types/node
  • @types/supertest
• @typescript-eslint packages: TypeScript support and rules for ESLint
  • @typescript-eslint/eslint-plugin: rules for TypeScript linting
  • @typescript-eslint/parser: alternative parser that understands TypeScript
• eslint: static code analysis
• jest: testing framework for JavaScript
• nodemon: automatic server restart on changes
• supertest: complementing API testing library
• ts-jest: support for running Jest tests written in TypeScript
• typescript: support for static typing in JavaScript

Environment variables

The Docker Compose services use environment files (.env.database and .env.backend) to fetch environment variables. The required variables for each service are listed below.

Example files are included in the repository. They work with production mode right away. For development mode, make sure the connection string is corrected (database:5432 -> localhost:5000 with default containerized database).

Database

• POSTGRES_DB: name of the used PostgreSQL database
• POSTGRES_USER: PostgreSQL username
• POSTGRES_PASSWORD: PostgreSQL password

Backend

• PRISMA_DB_URL: connection string used by Prisma
  • connection_limit: (optional): connection pool limit
  • pool_timeout: (optional): the time every connection remains open
• PRIVATE_TOKEN: secret that verifies a JWT token

Running development

The easiest way to run the service in development mode is to start the database in a container and the backend locally. When changes to TS files are made, the backend will live reload them. In case of Prisma files (database changes), the backend needs to be manually restarted.

docker-compose up database    # Start the containerized database
cp .example-env.backend .env  # Create and modify settings for backend
npm install                   # Install dependencies
npm run devBuild              # (Leave running) Generate and transpile code
npm run devServe              # (Leave running) Run the backend service

Running production

Running the service in production mode is really straight-forward. Just create environment files with desired settings and start the containers.

cp .example-env.database .env.database  # Create settings for database
cp .example-env.backend .env.backend    # Create settings for backend
docker-compose up                       # Run the whole service

API documentation

Documentation is written in the OpenAPI 3.0 format. It can be found in api-doc.yml.