dbmedialab/reader-critics

//
// LESERKRITIKK v2 (aka Reader Critics)
// Copyright (C) 2017 DB Medialab/Aller Media AS, Oslo, Norway
// https://github.com/dbmedialab/reader-critics/
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software
// Foundation, either version 3 of the License, or (at your option) any later
// version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <http://www.gnu.org/licenses/>.
//

import * as colors from 'ansicolors';
import * as IORedis from 'ioredis';
import * as stripUrlAuth from 'strip-url-auth';

import config from 'app/config';

import * as app from 'app/util/applib';

const log = app.createLog('redis');
const checkURL = /^redis:\/\/.+$/;

export const dbMessageQueue = 'message-queue';
export const dbSessionCache = 'session-cache';

// This function directly returns the Redis client object and does not produce
// a promise, as opposed to most other functions. Mostly because this function
// is used to create client objects for several other middleware objects like
// message queue or session cache (all third-party modules) it needs to return a
// client object directly. Luckily, IORedis returns synchronously and handles
// delays during the connection phase internally.

export function createRedisConnection(which : string) : IORedis.Redis {
    if (![dbMessageQueue, dbSessionCache].includes(which)) {
        throw new Error(`Unknown Redis database "${which}"`);
    }

    const url = config.get(`db.redis.url.${which}`);

    if (!checkURL.test(url)) {
        throw new Error('Invalid Redis connection URL');
    }

    const redis : IORedis.Redis = new IORedis(url);

    redis.on('connect', () => {
        log('Connecting to %s at %s', which, colors.brightWhite(stripUrlAuth(stripUrlAuth(url))));
    });
    redis.on('reconnecting', () => {
        log('Reconnecting ', which);
    });

    return redis;
}