Eurovision-song-contest

This exercise application implements a small system to count the results of the Eurovision Song Contest.

• An OpenAPI specification designed to provide Api Design First approach.

• Vert.x Web API Contract used to expose endpoint paths and validate them with OpenAPI spec.

• An HTTP Server expose an endpoint with relevant paths alligned with OpenAPI spec and controlled by Web API Contract.

• Endpoint paths connected to HTTP Server router built with OpenAPI directly to EventBus services.

• An EventBus allowed many parts of application to communicate each other.

• Reactive pattern implemented to develop transaction services, mainly RxJava2, asychronous and Java streams.

• Two verticles developed: a vote transaction services verticle(Java) and a metrics reporter(Kotlin)

• Thanks to Vert.x polyglot support Java and Kotlin used with verticle developments

• A metric reporter designed to push metrics to the eventbus topic

• A dashboard designed to check vote result through a webscoket and read latest vote result metrics from the eventbus topic

• Reactive and non blocking PostgreSQL client used to handle database connections, queries and transactions.

• Application dockerized from adoptopenjdk/openjdk8-openj9:alpine-jre image.

• A PostgreSQL database preffered to store application data through reactive database driver. During installation all required database, schema, table and indexes are created.

• Application and database docker containers composed and run with Docker Compose.

Prerequisites

• JDK 8+

• Docker Engine

• Docker Compose

Building

To package your application:

./gradlew clean build -x test

Run

To compose and run your application:

docker-compose up --build

Note	Docker composes and runs an application container and a database container

To stop application and db containers:

docker-compose down -v

Getting Started

Post a vote with curl:

curl -X POST "http://localhost:8888/votes/2020" -H "accept: application/json" -H "Content-Type: application/json" -d "{\"countryFrom\":\"Netherlands\",\"votedFor\":\"Belgium\"}"

Get top three countries for the specified year

curl -X GET "http://localhost:8888/votes/2020" -H "accept: application/json"

Get the top three favorite songs for the specified year and country

curl -X GET "http://localhost:8888/votes/2020/Netherlands" -H "accept: application/json"

To check online results launch Vote Results Dashboard at http://localhost:9999/

Help

• Vert.x Documentation

• Vert.x Stack Overflow

• Vert.x User Group

• Vert.x Gitter