Heroku Scheduler.rake set up - ruby-on-rails

Question

Following the Railscasts am trying to set up a scheduled rake task to send an email to an administrator user:
desc 'Testing rake task to generate email'
task :overtime_report => :environment do
hospital_bookings = HospitalBooking.scoped
hospital_booking = hospital_bookings
user = User.where(:roles => :administrator)
if params[:format] == 'pdf'
hospital_bookings = hospital_bookings.where(:day => Date.today.beginning_of_month..Date.today.end_of_month)
end
respond_to do |format|
format.html
format.pdf do
render :pdf => "#{Date.today.strftime('%B')} Overtime Report",
:header => {:html => {:template => 'layouts/pdf.html.erb'}}
OvertimeMailer.overtime_pdf(user, hospital_booking).deliver
end
end
end
Controller
class HospitalBookingsController < ApplicationController
#load_and_authorize_resource
before_filter :admin_user, :only => [:index]
def index
#hospital_bookings = HospitalBooking.scoped
system "rake overtime_report Mail_ID=#{params[:id]} &"
flash[:notice] = 'Delivering Overtime Report'
end
Just need a bit of guidance if I am heading in the right direction.

Answer 1

Not much of your code makes sense I'm afraid:
A rake task is not an action in a controller so your use of params and respond_to will not work at all.
If it's a scheduled task to be run at a certain interval then you don't want a controller at all.
Your controller contains a huge security vulnerability by passing user input directly to the command line in the form of Mail_ID=#{params[:id]}.
Passing the Mail_ID option above into the rake task doesn't make sense as it's never used.
You should never call system commands from a controller.
hospital_booking = hospital_bookings makes no sense as it does nothing.
render isn't going to do anything either, that's the responsibility of the ActionMailer object you create.
You probably want something like:
desc 'Send hospital bookings overtime report'
task :overtime_report => :environment do
bookings = HospitalBooking.where(:day => Date.today.beginning_of_month..Date.today.end_of_month).all
user = User.where(:roles => :administrator).first
OvertimeMailer.overtime_pdf(user, hospital_bookings).deliver
end