haraka-plugin-redis

haraka-plugin-redis

Connects to a redis instance. By default it stores a redis connection handle at server.notes.redis. See below to get a custom DB handle attached to another database.

Config

The redis.ini file has the following sections (defaults shown):

[server]

; host=127.0.0.1
; port=6379

[pubsub]

; host=127.0.0.1
; port=6379

Publish & Subscribe are DB agnostic and thus have no db setting. If host and port and not defined, they default to the same as [server] settings.

[opts]

; see https://www.npmjs.com/package/redis#options-object-properties
; db=0
; password=battery-horse-staple

Options specified in redis.ini[opts] are applied to the server config, the pubsub config, AND the configurations of any plugins that inherit this plugin. This is ideal if the redis server requires a password. Specify it once in [opts]. If other redis connections need a different value (such as a unique DB), they must specify it. For plugins, all options are stored in the plugins [redis] section of its config file.

Usage (shared redis)

Use redis in your plugin like so:

if (server.notes.redis) {
    server.notes.redis.hgetall(...);
        // or any other redis command
}

Publish/Subscribe Usage

In your plugin:

exports.results_init = function (next, connection) {
    var plugin = this;
    plugin.redis_subscribe(connection, function () {
        connection.notes.redis.on('pmessage', function (pattern, channel, message) {
            plugin.do_something_with_message(message, ...);
        });
        next();
    });
}
// be nice to redis and disconnect
exports.hook_disconnect = function (next, connection) {
    this.redis_unsubscribe(connection);
}

Custom Usage

This variation lets your plugin establish its own Redis connection, optionally with a redis db ID. All redis config options must be listed in your plugins config file in the [redis] section.

exports.register = function () {
    const plugin = this;
    plugin.inherits('redis');

    plugin.cfg = plugin.config.get('my-plugin.ini');

    // populate plugin.cfg.redis with defaults from redis.ini
    plugin.merge_redis_ini();

    // cluster aware redis connection(s)
    plugin.register_hook('init_master', 'init_redis_plugin');
    plugin.register_hook('init_child',  'init_redis_plugin');
}

When a db ID is specified in the [redis] section of a redis inheriting plugin, log messages like these will be emitted when Haraka starts:

[INFO] [-] [redis] connected to redis://172.16.15.16:6379 v3.2.6
[INFO] [-] [limit] connected to redis://172.16.15.16:6379/1 v3.2.6
[INFO] [-] [karma] connected to redis://172.16.15.16:6379/2 v3.2.6
[INFO] [-] [known-senders] connected to redis://172.16.15.16:6379/3 v3.2.6

Notice the database ID numbers appended to each plugins redis connection message.

Changelog

1.0.10 - 2019-04-09

• merge ALL of [opts] into [server] config (fixes #18)
• merge all of [opts] into [pubsub] config
• include an empty config/redis.ini
• add defaultOpts once, vs defaults in two places