pool.js

'use strict';

const ldap = require('ldapjs');

class LdapPool {
    constructor(config) {
        this._set_config(config);
        this.pool = { servers: [] };
    }

    _set_config(config = {}) {
        if (config.main === undefined) config.main = {};
        this.config = {
            servers: config.main.server || ['ldap://localhost:389'],
            timeout: config.main.timeout,
            tls_enabled: config.main.tls_enabled || false,
            tls_rejectUnauthorized: config.main.tls_rejectUnauthorized,
            scope: config.main.scope || 'sub',
            binddn: config.main.binddn,
            bindpw: config.main.bindpw,
            basedn: config.main.basedn,
            aliases: config.aliases,
            authn: config.authn,
            authz: config.authz,
            rcpt_to: config.rcpt_to,
        };
        return this.config;
    }

    _get_ldapjs_config() {
        const config = {
            url: this.config.servers.shift(),
            timeout: this.config.timeout,
        };
        this.config.servers.push(config.url);
        if (this.config.tls_rejectUnauthorized !== undefined) {
            config.tlsOptions = {
                rejectUnauthorized: this.config.tls_rejectUnauthorized,
            };
        }
        return config;
    }

    _create_client(next) {
        const client = ldap.createClient(this._get_ldapjs_config());

        client.on('connectError', (err) => {
            console.error(err);
        });

        if (!this.config.tls_enabled) return next(null, client);

        client.starttls({}, null, (err) => {
            if (err) return next(err);
            next(null, client);
        });
    }

    close(next) {
        if (this.pool.servers.length <= 0) return next();

        while (this.pool.servers.length > 0) {
            this.pool.servers.shift().unbind();
            if (this.pool.servers.length === 0) next();
        }
    }

    _bind_default(next) {
        const cfg = this.config;

        this._create_client((err, client) => {
            if (err) return next(err);

            if (cfg.binddn && cfg.bindpw) {
                client.bind(cfg.binddn, cfg.bindpw, (err2) => {
                    next(err2, client);
                });
            } else {
                next(null, client);
            }
        });
    }

    get(next) {
        const pool = this.pool;

        if (pool.servers.length >= this.config.servers.length) {
            // shift and push for round-robin
            const client = pool.servers.shift();
            pool.servers.push(client);
            return next(null, client);
        }

        this._bind_default((err, client) => {
            pool.servers.push(client);
            next(err, client);
        });
    }
}

exports.LdapPool = LdapPool;