Node.js - application configuration in JSON file

In this short article, we would like to show how to store additional Node.js application configuration in JSON file.

The main concept of the presented solution is to:

1. read and parse config.json at the application beggining,
2. exit the application when it is impossible to read config, printing error message.

Practical example

Example index.js file:

const fs = require('fs');
const path = require('path');

let globalConfig;

try {
    const filePath = path.resolve(__dirname, 'config.json');
    const fileJson = fs.readFileSync(filePath, 'utf-8');
    globalConfig = JSON.parse(fileJson);
} catch (ex) {
    console.error(`Config file reading error. (${ex.message})`);
    process.exit(1);
}

// Application source code here ...

// e.g.:
console.log(globalConfig.username);
console.log(globalConfig.password);

Example config.json file:

{
    "username": "john",
    "password": "P@ssword"
}

Console:

john
P@ssword

Preview:

See also

1. Node.js - read JSON files