nginx-proxy-manager/backend/lib/utils.js

const exec = require('child_process').exec;

module.exports = {

    /**
     * @param   {String} cmd
     * @returns {Promise}
     */
    exec: function (cmd) {
        return new Promise((resolve, reject) => {
            exec(cmd, function (err, stdout, stderr) {
                if (err && typeof err === 'object') {
                    reject(err);
                } else {
                    resolve(stdout.trim());
                }
            });
        });
    }
};