/notifications-demo

Primary LanguageKotlin

Libraries and Tech Specs

To demonstrate Ktor's full capability in building scalable web applications the following Ktor features and libraries were leveraged on;

Ktor Features

  • Routing: Handles incoming requests and provides a simple DSL to capture route mappings.
  • Authentication: Handles API authentication.
  • Call Logging: Logs application events.
  • Status pages: Handles exceptions and errors that occur within a request lifecycle and returns an appropriate response.
  • Content Negotiation: Negotiating media types and serializing/deserializing JSON content.

External Libraries

Database

  • Exposed: ORM library developed by JetBrains, allowing for model definitions to be written in SQL format, while proving a simple interface and clean DSL.
  • HikariCP: Database connection and connection pooling.
  • Flyway: Handles database migrations
  • Caffeine: High performance in-memory cache based on Guava.

Testing

  • Jacoco: Mature test coverage and reporting.
  • Mockk: Easier mocks, stubs definitions using DSL allowing for easier testing.
  • Ktor-tests: Provides Ktor test engine to allow for high fidelity end to end integration tests.
  • Test Containers: Provides reusable database instances for testing
  • Kotest: Testing framework for rich assertions.

Logging

Utility

  • Koin - Dependency Injection.
  • Gradle with kotlin DSL - a widely adopted build tool, allowing us to write build scripts and code in Kotlin.
  • Valiktor - type-safe, powerful and extensible fluent DSL to validate objects in Kotlin.

Getting started

Configure Environment Variables

  • Create a .env file, with the format:
  • Create a project on firebase or use an existing one to retrieve the service-account.json file.
export DB_HOST=localhost
export DB_PORT=5432
export DB_NAME=notifications
export DB_USER=admin
export DB_PASSWORD=admin
export SERVICE_ACCOUNT_FILE_PATH=path_to_your_firebase_sa.json

Start Docker

  • Ensure sure that docker and docker compose are installed on your machine.
  • CD to /docker and run the following command to initialize the database
cd docker && docker-compose up

Start the application server

  • Run the following command to start the ktor sever
source .env && ./gradlew run
  • Open a web browser and go to http://0.0.0.0:8080/ and you should see "I'm running!" in the pagešŸš€

Run the tests

source .env && ./gradlew clean tests