Getting Your (Annoyingly Dynamic) IP Address Emailed To You Every Day

I recently moved house and with that had to adjust to a new internet service that is unfortunately not as reliable as my old one. As I rely on my raspberry pi as a remote media server, I need to know what the IP address is, which is a bit of a pain when it keeps changing while you’re out the house.

I started thinking “Maybe there’s a way I could automate the emailing of my IP address once a day” so I started investigating CLI mailers.

Initially I looked at sendmail but it seemed a little bit overkill for what I needed, and I got a little bit lost in the configuration options, but perhaps that’s just my poor attention span.

In the end I went for ssmtp and followed this guide for setting it up with my email address (I used a gmail account)*.

The next step was setting the pi to obtain the external ip address, and for this I used curl with checkip.dyndns.org and sent the output to a text file called todaysip.txt. This can be put in a script with the ssmtp email command, and it looks like this:

#!/bin/sh
date > date.txt && curl -s checkip.dyndns.org | sed -e 's/.*Current IP Address: //' -e 's/<.*$//' > todaysip.txt && paste date.txt todaysip.txt >> today.txt && tac today.txt | mail -s "IP Address" recipient@emailprovider.com

The next step was setting crontab to run the script at midday everyday. Job’s a good ‘un.**

If there’s a more elegant way of achieving the same result, I’d be interested in hearing it as this is a bit of a quick ‘n’ dirty solution.

*You will need to set-up a separate app password if you use Gmail’s 2-factor authentication.
**It took me a bit of troubleshooting to get this to work, but ultimately I used /bin/sh rather than /bin/bash – See source below

EDIT: Added date stamp to script.  Probably in an overkill kinda way.

_Sources:

_{1. http://iqjar.com/jar/sending-emails-from-the-raspberry-pi/}

_{2. http://askubuntu.com/questions/95910/command-for-determining-my-public-ip}

_{3. http://askubuntu.com/questions/23009/reasons-why-crontab-does-not-work}