Send mail outside rails project with CSV attachment

send_mail_outside_rails.rb

#!/usr/bin/env ruby

##
# Run ruby script outside rails project by loading rails env 
# Script will sent mail with csv attachment and run through cronjob
# Steps :-
# 1. Load rails environment
# 2. Set Mail SMTP configuration
# 3. Generate CSV
# 4. Configure mail
# 5. Send mail
# 6. Setup cronjob
##

# Load rails environment
require './config/environment'

## SMTP configuration
Mail.defaults do
  delivery_method :smtp, {
    user_name: 'sendgrid user_name',
    password: 'sendgrid password',
    domain: 'gmail.com',
    address: 'smtp.sendgrid.net',
    port: 587,
    authentication: 'plain',
    enable_starttls_auto: true
  }
end

## Generate CSV
 csv_string = CSV.generate do |csv|
  csv << ['C1', 'C2']
  csv << ['d1', 'd2']
end

## Configure mail
mail = Mail.new do
  to       '[email protected]'
  cc       '[email protected], [email protected]'
  from     '[email protected]'
  subject  'Email subject'
  add_file :filename => 'filename.csv', :content => csv_string
end

## Send mail
mail.deliver!

## Setup cronjob
# 1. crontab -e
# 2. 30 5 * * * /bin/bash -l -c 'cd /var/www/rails_project/current && RAILS_ENV=development ruby /home/user/scripts/script1.rb'
# Run job daily at 11:30 AM IST