gato

Gato is a lightweight wrapper tailored for effortless integration of LavinMQ, a robust messaging system using AMQP 0.9.1 protocols, within the Lucky framework. Designed to streamline the utilization of AMQP (Advanced Message Queuing Protocol) in Lucky applications, Gato simplifies the process of publishing and subscribing to queues, all while focusing on the unique features and capabilities of LavinMQ.

Key Features:

With Gato, harness the power of LavinMQ in your Lucky applications with ease, enhancing communication and workflow efficiency.

Installation

  1. Add the dependency to your shard.yml:

    # shard.yml

dependencies:
  gato:
    github: healtronlabs/gato

  2. Run shards install

  3. Open to this file src/shards.cr and add this line of code:

# src/shards.cr

require "gato"

  1. Go inside config folder, and create a new file gato.cr

  2. Add this config to the file you created on the previous step:

# config/gato.cr

Gato.configure do |settings|
  settings.amqp_url = ENV["LAVINMQ_URL"] # this code requires you to have an env variable under the name of LAVINMQ_URL which is the url to connect to lavinmq server
end

Usage

Publishing messages directly to the queue

Use publish method from Gato::Publisher class

Gato::Publisher.publish stringified_object, queue_name

Subscribing to messages

You will have to run it as a worker

# worker.cr

require "./app"
require "./lavin_handlers/**"

Habitat.raise_if_missing_settings!

if LuckyEnv.development?
  Avram::Migrator::Runner.new.ensure_migrated!
  Avram::SchemaEnforcer.ensure_correct_column_mappings!
end

# Disable query cache because all jobs run in the
# same fiber which means infinite cache
Avram.settings.query_cache_enabled = false

lavin_handlers = [
  {
    queue_name:      "new_lefa",
    message_handler: ->(msg : JSON::Any) { CreateLefa.handle_create_lefa(msg) },
  },
  {
    queue_name:      "update_lefa",
    message_handler: ->(msg : JSON::Any) { UpdateLefa.handle_update_lefa(msg) },
  },
]

Gato::Subscriber.subscribe lavin_handlers

The following are details for params passed to the subscribe method:

The subscribe method expect an array of named tuples, whereby each tuple gets a name of the queue and a method that will handle any message that will be published to that queue, the handler_method needs to be passed as an anonymous function that expects to receive a msg param that represents a published message to the queue that is defined in the same tuple. That message object is expected to be of type JSON::Any.

Contributing

:warning: This package needs more contributors whereby we still haven't covered all of the LavinMQ capabilities, such as streamings, exchanges, ... :warning:

  1. Fork it (https://github.com/healtronlabs/gato/fork)
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Contributors