website_monitor.rb

#!/usr/bin/ruby
require 'net/http'
require 'net/smtp' 
require 'uri'
require 'yaml'
require 'logger'

#README 
#FIELD NEEDS CHANGE - SEARCH AND REPLACE 
#<email_id> - 2 entries
#<email_pwd>
#<web_url_with_http_or_https>
#<welcome_msg_of_the_default_loading_page>
#<to_admin_addr>

def check_webpage(web_url, logger)
  
  begin
    url = URI.parse(web_url)
    net_conn = Net::HTTP.new(url.host, url.port)
    net_conn.use_ssl = url.scheme == "https"
    res = net_conn.get('/')
  
  rescue Exception => e
    logger.error("Pinging issue\n" + e.to_s)
    return { code: res ? res.code : 500, error: e.to_s }
  end
  
  return { code: res.code, content: res.body, error: "" }
end 

def send_gmail(to, msg, logger)
  
  gmail_server, gmail_port, gmail_acc, gmail_pwd = "smtp.gmail.com", 587, "<email_id>@gmail.com", "<email_pwd>"
   
  begin  
    smtp = Net::SMTP.new(gmail_server, 587)
    smtp.enable_starttls #gmail needs this encryption
    smtp.start("DOMAIN FILLER", gmail_acc, gmail_pwd, :login)  do |s| 
      s.send_message(msg, gmail_acc, to)
    end  
  rescue Exception => e  
      logger.error("Exception occured: " );
      logger.error(e);
  end

end


logger = Logger.new('website_checker.log', 'daily')

web_url = "<web_url_with_http_or_https>"
welcome_msg = "<welcome_msg_of_the_default_loading_page>"

server_online = false;

response = check_webpage(web_url, logger)

if (response[:code] == "200" && response[:content].include?(welcome_msg))
    server_online = true
else

  subject = "Ping failed - #{web_url}"
  to_addr = "<to_admin_addr>"
  
  msg = [
    "From: WebMonitor <<email_id>@gmail.com>",
    "To: Admin <#{to_addr}>",
    "Subject: #{subject}",
    "",
    "Hi,",
    "#{subject}",
    "#{response[:error]}",
    "",
    "",
    "Content:",
    "#{response[:content]}"
  ].join("\r\n");
   
  send_gmail(to_addr, msg, logger)
end