SOPJ

SOPJ stands for Simple Online Programming Judge.

The judge website is built with Express, TypeScript, and MariaDB. The sandbox environment runs in Docker containers.

Prerequisites

• NodeJS (JavaScript Runtime)
• TypeScript Compiler
• MariaDB

For server-side hosting:

• PM2 Node Process Manager (npm install -g pm2)

For sandbox code executor:

• Docker Command Line Interface

Setup

Set environment variables in include/env.ts:

export const DB_PASSWORD = "<db password>";
export const DB_USER = "<db user>";
export const DIR = "<project folder>/site";
export const HOSTNAME = "<host name>";
export const JUDGE_SUPPORT = true;
export const JWTSECRET = "<secret key for JWT encryption>";
export const PORT = <port>;
export const SESSIONSECRET = "<session secret key>";

Install node packages:

npm install

Test run web server:

npm run webserver

MariaDB

Ensure the application has the correct permissions to access the database.

Check permissions:

SELECT host, user FROM mysql.user;
SHOW GRANTS FOR '<user>'@'<host>';

Set permissions:

CREATE USER '<user>'@'<host>' IDENTIFIED BY '<password>';
GRANT ALL PRIVILEGES ON <database>.* TO '<user>'@'<host>';
FLUSH PRIVILEGES;

Docker

Ensure the application has access to Docker.

sudo usermod -aG docker <user>

Build compiler and runner images:

sudo docker build -t online_judge_compiler judge/compiler
sudo docker build -t online_judge_runner judge/runner

Deployment

Setup:

sudo npm install -g pm2

Build:

source scripts/build.sh

Deploy:

source scripts/deploy.sh