Deploying Rails 4 apps with Resque and Redis to Heroku using Unicorn with a Procfile.

Gemfile

# and whatever other gems you need

gem 'resque', '~> 1.24.1'
gem 'unicorn', '~> 4.6.2'

Procfile

# lives in app root

web: bundle exec unicorn -p $PORT -c ./config/unicorn.rb
resque: env TERM_CHILD=1 QUEUE=* bundle exec rake resque:work

redis.rb

# lives in config/initializers/redis.rb
# assumes you're using the Redis Cloud addon (NOT Redis TOGO)

if ENV["REDISCLOUD_URL"]
  $redis = Resque.redis = Redis.new(:url => ENV["REDISCLOUD_URL"])
end

resque.rake

# lives in lib/tasks/resque.rake

require 'resque/tasks'

task "resque:preload" => :environment

unicorn.rb

# lives in config/unicorn.rb

worker_processes Integer(ENV["WEB_CONCURRENCY"] || 3)
timeout 15
preload_app true


before_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn master intercepting TERM and sending myself QUIT instead'
    Process.kill 'QUIT', Process.pid
  end

  defined?(ActiveRecord::Base) and
    ActiveRecord::Base.connection.disconnect!

  if defined?(Resque)
    Resque.redis.quit
    Rails.logger.info('Disconnected from Redis')
  end
end

after_fork do |server, worker|
  Signal.trap 'TERM' do
    puts 'Unicorn worker intercepting TERM and doing nothing. Wait for master to send QUIT'
  end

  if defined?(Resque)
    Rails.logger.info('Connected to Redis')
  end
end