NatsListener
Installation
Add this line to your application's Gemfile:
gem 'nats_listener'
And then execute:
$ bundle
Or install it yourself as:
$ gem install nats_listener
Usage
For usage in your project we offer:
- Create
initializer.rb
or manually callNatsListener.current.establish_connection(service_name: [YOUR SERVICE NAME], servers: [NATS_SERVERS_URLS])
- For publishing you can use
NatsListener.current.publish
serializing message with two strategies(protobuf
andjson
). Json strategy is proposed in https://github.com/beastia/nats_listener. Protobuf strategy is included into https://github.com/beastia/nats_streaming_listener. - For receiving messages we offer subscribers
Protobuf strategy
2.3.3 :006 > require 'nats_streaming_listener'
=> true
2.3.3 :006 > m = NatsStreaming::NatsMessage.new(sender_service_name: 'ololo', receiver_action_name: 'ololo1', receiver_action_parameters:[1,2,3].map(&:to_s), message_timestamp: Time.now.utc.to_i, transaction_id: 'unique')
=> #<NatsListener::NatsMessage sender_service_name="ololo" receiver_action_name="ololo1" receiver_action_parameters=["1", "2", "3"] message_timestamp=1538902717 transaction_id="unique">
2.3.3 :007 > m.serialize
=> "\n\x05ololo\x12\x06ololo1\x1A\x011\x1A\x012\x1A\x013 \xBD\x95\xE7\xDD\x05*\x06unique"
Json strategy
2.3.3 :009 > m = NatsListener::Message.new({action: 'ololo'})
=> #<NatsListener::Message:0x007ff1869a3628 @message={:publisher=>nil, :timestamp=>2018-10-07 09:00:29 UTC, :message_id=>"7dfc4de9-d920-4cc1-8cfe-5e85f7fb855d", :data=>{:action=>"ololo"}}>
2.3.3 :010 > m.to_json
=> "{\"publisher\":service1,\"timestamp\":\"2018-10-07T09:00:29.133Z\",\"message_id\":\"7dfc4de9-d920-4cc1-8cfe-5e85f7fb855d\",\"data\":{\"action\":\"ololo\"}}"
Creating client
NatsListener::Client.current = NatsListener::Client.new(
logger: Ougai::Logger.new(STDOUT),
skip: false,
catch_errors: true,
catch_provider: Rollbar
)
All arguments are optional.
logger
- logger that you can pass to application. It will be called to debug messages.
skip
- skip calls. Useful for tests
catch_errors
- catch errors, log them and pass to catch_provider
catch_provider
- provider that is called when error occurs, e.g. Rollbar.
Subscribers
For using subscribers we offer one quite simple way:
- Create
subscribers
folder. - Create your own subscriber derived from
NatsListener::Subscriber
- Load and subscribe all subscribers, e.g.
NatsListener::Client.current = NatsListener::Client.new(
logger: Ougai::Logger.new(STDOUT),
skip: false,
catch_errors: true,
catch_provider: Rollbar
)
NatsListener::Client.current.establish_connection(service_name: [YOUR SERVICE NAME], servers: [NATS_SERVERS_URLS])
path = Rails.root.join('app', 'subscribers', '*.rb')
Dir.glob(path) do |entry|
entry.split('/').last.split('.').first.camelize.constantize.new.subscribe
end
- ???
- PROFIT
NB!
Right now nats functionality is proved to work aside of Puma workers because of the conflicts between puma
and nats-pure
gems.
TODO:
- Add nats-streaming subscribers
- Add usage of nats-streaming for calls
Development
After checking out the repo, run bin/setup
to install dependencies. Then, run rake spec
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/beastia/nats_listener. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.
Code of Conduct
Everyone interacting in the NatsListener project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.