RocketChat/Rocket.Chat

import fs from 'fs';

function hasDockerEnv(): boolean {
    try {
        fs.statSync('/.dockerenv');
        return true;
    } catch (err) {
        return false;
    }
}

function hasDockerCGroup(): boolean {
    try {
        return fs.readFileSync('/proc/self/cgroup', 'utf8').indexOf('docker') !== -1;
    } catch (err) {
        return false;
    }
}

function check(): boolean {
    return hasDockerEnv() || hasDockerCGroup();
}

let _isDocker: boolean;
export const isDocker = function (): boolean {
    if (_isDocker === undefined) {
        _isDocker = check();
    }

    return _isDocker;
};