Sparql Enpdoint Availability

This service checks the availability of a list of public SPARQL endpoints. It offers a web interface to check the status of the endpoints and a REST API to retrieve the status of the endpoints.

For this purpose, using the Jena library this query is sent to each endpoint every hour:
ASK {?s ?p ?o}
If the SPARQL endpoint gives a response then it is active, otherwise it's not.

Documentation

• Demo
• REST-API
• Running develop enviroment
• Installation
• Building and testing
• CI/CD

Demo

• Self-hosted (complete list of endpoints)
• Heroku (limited list of endpoints)
  Admin demo credentials:
  
  • username: admin
    
  • password: admin

REST-API

• Swagger Documentation
  You can test the API using the Swagger UI.
  

Requirements

• Java 11+ or Docker

Running develop enviroment with Maven

Sparql endpoint availability is a Spring Boot application built using Maven.

Clone repo:

git clone https://github.com/lglot/sparql-endpoint-availability.git
cd sparql-endpoint-availability

• Run the application:
  

./mvnw spring-boot:run 

Viewing the running application

To view the running application, visit http://localhost:8080 in your browser

Accessing the application with admin privileges

The application by default has a admin user with the following credentials:

• username: admin
  
• password: admin
  

You can change the credentials in the src/main/resources/application.properties file

Installation with Docker

The application image is available on Docker Hub with the latest updates.

The application requires a running database.
Actually, the application is configured to use a PostgreSQL, MySQL or H2 databases.
The easiest way to install the stack is to use docker-compose.

Copy docker-compose.yml.example in docker folder to docker-compose.yml
The default configuration is for MySQL database.
Run the following command to start the application:

docker-compose -f docker/docker-compose.yml up -d

Example of docker-compose file for MySQL database:

version: '3.0'

services:
  app:
    image: lglot/sparql_endpoint_availability:v0.1
    container_name: app
    ports:
      - "8080:8080"
    depends_on:
      - db
    restart: unless-stopped
    environment:
      - SPRING_SQL_INIT_PLATFORM=mysql        # or postgres or h2
      - SPRING_DATASOURCE_URL=jdbc:mysql://db:3306/sparql_endpoint_availability
      - SPRING_DATASOURCE_USERNAME=sparql     # database username
      - SPRING_DATASOURCE_PASSWORD=sparql     # database password
      - APP_ADMIN_USERNAME=admin              # admin username
      - APP_ADMIN_PASSWORD=admin              # admin password
      - SERVER_SERVLET_CONTEXT_PATH=/sparql   # required for reverse proxy
      
      - SERVER_PORT=8080                      # optional, if you want to change the default port
                                              # but remember to change the port in the ports section
      - JWT_TOKEN_SECRET=a_very_long_secret   # secret for JWT token 

  db:
    image: mysql:latest
    container_name: db
    environment:
      MYSQL_ROOT_PASSWORD: root
      MYSQL_USER: sparql
      MYSQL_PASSWORD: sparql
      MYSQL_DATABASE: sparql_endpoint_availability   #is the same as SPRING_DATASOURCE_URL
    volumes:
      - db_volume:/var/lib/mysql
    restart: unless-stopped

volumes:
  db_volume:
    external: false

Recommended Variables

Variable	Default	Value	Description
SPRING_SQL_INIT_PLATFORM	h2	<"mysql","postgresql","h2">	Set database type
SPRING_DATASOURCE_URL	jdbc:h2:mem:db	jdbc:{dbms}:{database_url}	Set database URL, as: jdbc:mysql://localhost:3306/db for MySQL database with hostname localhost and port 3306 and database name db jdbc:postgresql://db:5432/sparql_db for PostgreSQL database with hostname db and port 5432 and database name sparql_db
SPRING_DATASOURCE_USERNAME	sparql	<Database username>	Set database username
SPRING_DATASOURCE_PASSWORD	sparql	<Database password>	Set database password
APP_ADMIN_USERNAME	admin	<Admin username>	Set admin username
APP_ADMIN_PASSWORD	admin	<Admin password>	Set admin password, it's recommended to change the default one

Optional Variables

Variable	Default	Value	Description
SERVER_SERVLET_CONTEXT_PATH	unset	<Context path>	Set context path, it's required for reverse proxy
SERVER_PORT	8080	<Port>	Set web port, change also the port in the ports section in docker-compose file
JWT_TOKEN_SECRET	a_very_long_secret	<Secret>	Set secret for JWT token, it's recommended to change the default one

---

Building and testing

The test suite includes UI tests with Selenium.
Browser support is limited to Chrome, Firefox and Edge.

Default configuration is for Firefox browser.

 ./mvnw clean package -Dbrowser=your_browser    

CI/CD

The application is configured to use GitHub Actions for CI/CD.
The workflow is triggered on every push and pull request.
The workflow includes the following steps:

• Build the application
• Run the test suite
• Build the docker image
• Push the docker image to Docker Hub