ThriftRack

ThriftRack implements thrift Compact Protocol + HTTP Transport with rack, and makes it easy to write a server with convention.

Add this line to your application's Gemfile:

gem 'thrift_rack'

And then execute:

$ bundle

Or install it yourself as:

$ gem install thrift_rack

Assume you use rails only with activemodel、activerecord、activesupport. Because ThriftRack act as controller and view, you do not need actionview and actionpack

You cloud new a rails app use this command

rails new demo --skip-action-mailer --skip-action-mailbox --skip-action-text --skip-active-record --skip-active-storage --skip-action-cable --skip-sprockets --skip-javascript --skip-turbolinks --skip-test --skip-system-test --skip-bootsnap --api --skip-webpack-install

Suppose you has a thrift named math.thrift to add two number:

# math.thrift
namespace rb thrift.math # namesapce should same with filename

service MathService { # Math is capitalized from Math
  int add(1: int i, 2: int j)
}

then you should implement this thrift in math_server.rb

class MathServer < ThriftRack::Server
  def add(i, j)
    i + j
  end
end

Then change the config.ru

require_relative 'config/environment'
app = ThriftRack.app(ThriftRack::Server.children)
run app

Another config under initializers

#initializers/thrift.rb
Dir["#{Rails.root}/lib/thrift/**/*.rb"].each { |file| require file } # support generate thrift files under lib/thrift
Dir["#{Rails.root}/app/servers/*.rb"].each { |file| require file } # support servers under app/servers

ThriftRack.redis = Redis.new
ThriftRack::Logger.tag = { key: value} # tag to logs

at_exit do
  ThriftRack::Logger.logger.close
end

Then run this bash

rackup

what happend?

• We implement the math.thrift with POST method at /math path
• A Server seems like a controller, except that you do not need to write routes.
• We replace the default rails rack entrance, but it still a rack server. You could use puma to web server, and enjoy puma's advantage.
• Client will auto retry with network jitter, Atom ensure each request at most processed once.
• /ping should be use to health check, all request to /ping will not be log
• ThriftRack::Logger log each rpc request with json format. You could use ELK to analyze each request

client cloud write like this

class Math
  attr_accessor :client
  def initialize(request_id = "no-request-id") # web should has one request_id
    @client = ThriftRack::Client.new("http://127.0.0.1:300/math", ThriftClientClass, request_id)
  end

  def add(i, j)
    self.client.add(i, j)
  end
end

Another config under initializers

#initializers/thrift.rb
Dir["#{Rails.root}/lib/thrift/**/*.rb"].each { |file| require file }

ThriftRack::Client.config Rails.application.class.parent.name.underscore

what happend?

• Client will auto generate a rpc_id to tracer rpc request
• Client will add app_name to header
• Client use HTTP 1.1, wich persistent tcp connection with multi http requests
• Client has a connection pool, network error will auto retry
• Client will log each rpc process time

you chould write a supperclass like under, other client inherit superclass

1. you could write a around_action to set request

   class ApplicationController < ActionController::API
     around_action :set_thread_local_request
   
     private
   
     def set_thread_local_request
       Thread.current["request"] = request
       yield
     ensure
       Thread.current["request"] = nil
     end
   end

2. write a superclass

   class ClientBase
     def initialize(req = nil)
       if req
         @request_id = req.request_id
       end
     end
   
     def request_id
       @request_id ||= Thread.current["request"] ? Thread.current["request"].request_id : "no-request-id"
     end
   
     def client
       ThriftRack::Client.new("http:127.0.0.1:3000/#{_namespace.underscore}", _client_class, request_id)
     end
   
     def respond_to_missing?(method, include_private = false)
       self.client.respond_to?(method)
     end
   
     def method_missing(method, *args)
       return super unless self.client.respond_to?(method)
       self.class_eval do
         define_method method.to_sym do |*params|
           self.client.public_send(method, *params)
         end
       end
       self.public_send(method, *args)
     end
   
     private
   
     def _namespace
       @namespace ||= self.class.name
     end
   
     def _client_class
       "Thrift::#{_namespace}::#{_namespace}Service::Client".constantize
     end
   
     class << self
       def default
         self.new
       end
   
       def respond_to_missing?(method, include_private = false)
         self.default.respond_to?(method)
       end
   
       def method_missing(method, *params)
         return super unless self.default.respond_to?(method)
         define_singleton_method method.to_sym do |*args|
           self.default.public_send(method, *args)
         end
         self.public_send(method, *params)
       end
     end
   end

3. inherit super class

   class Math < ClientBase
     def add(i, j)
       self.client.add(i, j)
     end
   end

4. use

   Math.add(1, 2) # will auto assign request_id is with request
   

After checking out the repo, run bin/setup to install dependencies. 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.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/thrift_rack. 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.

The gem is available as open source under the terms of the MIT License.

Everyone interacting in the ThriftRack project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.