Bandwidth-Aid: A VPN disconnect reminder script

Mike Ackerman, Former Senior Developer

Article Category: #Code

Posted on

Do you often forget to disconnect from a VPN connection? Try this out for a handy reminder!

VPNs are great for allowing you to do certain things that require being on your company's network while you're on an external internet connection. At Viget, we use a VPN for a number of activities: connecting to internal servers, viewing secure internal websites, deploying the latest code to certain servers, etc.

Recently, while working from home, I kept noticing that my internet felt slow. I'd hop on over to speedtest.net and see much lower than expected results. Before calling up my ISP, I noticed that I had forgotten to disconnect from the VPN! Connected for 8-15 hours, routing all of my traffic through our company's private network! :(

So, I came up with a solution: a small ruby script that runs every 10 minutes to check whether I'm connected to the VPN, and if I have been for more than 10 minutes, yell at me.

Note: my solution will only work on OSX, as it uses say and osascript for creating a dialog box notification

Steps to using it:

  • 1. Install Ruby (I recommend homebrew or rbenv)
  • 2. Save the contents of the script (found below) in a file in your home directory: /home/username/vpn_status_reminder.rb

    • Script contents:

# /home/username/vpn_status_reminder.rb

if connected_to_vpn?
 if already_connected?
   send_notification
 else
   set_connected_status
 end
else
 if already_connected?
   set_disconnected_status
 end
end

BEGIN {
 require 'fileutils'

 VPN_CONNECTED_FILENAME = "./VPN_CONNECTED.txt"

 def ifconfig_output
   @ifconfig_output ||= `/sbin/ifconfig`.strip
 end

 def connected_to_vpn?
   ifconfig_output.include?("ppp0")
 end

 def set_connected_status
   FileUtils.touch(VPN_CONNECTED_FILENAME)
 end

 def already_connected?
  File.exist?(VPN_CONNECTED_FILENAME)
 end

 def set_disconnected_status
   File.delete(VPN_CONNECTED_FILENAME)
 end

 def send_notification
   `say -v Zarvox "You are connected to the VPN"`
   `osascript -e 'tell app "Finder" to display dialog "\u{203C}\u{1F6A8}\u{203C} Connected to VPN \u{203C}\u{1F6A8}\u{203C}"'`
 end
}
  • 3. In your terminal, modify your cron scheduled jobs:
    • a. Determine where your ruby executable is: which ruby
    • b. Write down or store this value excluding the last /ruby part. example: if your output is /usr/bin/ruby the result would be /usr/bin
    • c. Update your cron jobs: EDITOR=nano crontab -e hit Enter and paste the following content: */10 * * * * /bin/bash -c 'export PATH=INSERT_HERE:$PATH; cd $HOME/; ruby vpn_status_reminder.rb', followed by ctrl+x, Y, Enter. Where INSERT_HERE should be replaced with the result of step 3.b.

Do you like this solution or have any ideas for making it better? Let me know in the comments below!

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