error in fetching mail using griddler(mandrill) - ruby-on-rails-4

Question

I am implementing griddler(using Mandrill) to fetch e-mail in my app.
This is my class to receive mail
#app/email_receivers/incoming.rb
class EmailReceiver < Incoming::Strategies::Mandrill
def receive(mail)
%(Got message from #{mail.to.first} with subject "#{mail.subject}")
end
end
req = Rack::Request.new(Rails.env)
result = EmailReceiver.receive(req)
This is my rails controller that calls receive method of EmailReceiver class.
#emails_controller.rb
class EmailsController < ActionController::Base
def create
if EmailReceiver.receive(request)
render :json => { :status => 'ok' }
else
render :json => { :status => 'rejected' }, :status => 403
end
end
end
Routes for calling create method of EmailsController
#routes.rb
Rails.application.routes.draw do
post '/emails' => 'emails#create'
end
Note:- After running server in production environment
rails s -e production
I got this error
/home/bvc-2/.rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/request.rb:192:in `[]=': string not matched (IndexError)
Where "puts req" in
req = Rack::Request.new(Rails.env)
turns out to be:
#<Rack::Request:0xc3bace8 #env="production">
And my config/application.rb file is:-
require File.expand_path('../boot', __FILE__)
require 'rails/all'
# Require the gems listed in Gemfile, including any gems
# you've limited to :test, :development, or :production.
Bundler.require(*Rails.groups)
ActionMailer::Base.smtp_settings = {
:address =>"smtp.gmail.com",
:port => 587,
:domain => "gmail.com",
:user_name => "***#gmail.com",
:password => "pass*******",
:authentication => 'plain',
:enable_starttls_auto => true
}
module ComplaintSystem
class Application < Rails::Application
# Settings in config/environments/* take precedence over those specified here.
# Application configuration should go into files in config/initializers
# -- all .rb files in that directory are automatically loaded.
# Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
# Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
# config.time_zone = 'Central Time (US & Canada)'
config.active_job.queue_adapter = :delayed_job
config.time_zone = 'Mumbai'
config.active_record.default_timezone = :local
# The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
# config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
# config.i18n.default_locale = :de
# Do not swallow errors in after_commit/after_rollback callbacks.
config.active_record.raise_in_transactional_callbacks = true
end
end

Answer 1

This type of error happens when you try to access a string variable as a Hash by mistake.
s = "hello world"
s["position"] = "programming is fun"
# > IndexError: string not matched
# > from (irb):5:in `[]='
# > from (irb):5
Look at your full stack trace and see where you are trying to do such operation.