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):
[socket]
[pubsub]
Publish & Subscribe are DB agnostic and thus have no db setting. If host and port and not defined, they default to the same as [socket] settings.
[opts]
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(...);
}
Publish/Subscribe Usage
In your plugin:
exports.results_init = function (next, connection) {
this.redis_subscribe(connection, () => {
connection.notes.redis.on('pmessage', (pattern, channel, message) => {
this.do_something_with_message(message, ...)
})
next()
})
}
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 () {
this.inherits('redis');
this.cfg = this.config.get('my-plugin.ini');
this.merge_redis_ini();
this.register_hook('init_master', 'init_redis_plugin');
this.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.