In a python program, I can use a try/except statement to avoid a crash. In the case of a would-be crash, I can save some data locally and email myself about the failure. What if the program is supposed to log data every hour and something outside the try/except statement fails? Though it may crash, we can minimize losses by having the program run on a schedule using cron…

Or maybe have the program wrapped in a giant whileTrueTryExcept statement… But somehow I sense that there is still room for single-point, fully destructive failure here. So, let’s go with cron…which itself can fail.

All of this build up is so I can ask: How do we notify ourselves if a cron job fails?

Below are some notes…. I still haven’t gotten cron itself to send an email.

1. Install ssmtp

On Ubuntu:

sudo apt-get install ssmtp

2. Configure the SSMTP Config File

sudo vim /etc/ssmtp/ssmtp.conf

root=your.email@gmail.com
mailhub=smtp.gmail.com:587
FromLineOverride=YES
UseSTARTTLS=YES
AuthUser=your.email@gmail.com
AuthPass=your_password
TLS_CA_File=~/cert.pem

3. The cert.pem File

You need this file, and I’ll show you how to create it, but to be honest I’m just following along with the advice from a user on askubuntu.com, so use at your own risk and headache. (Worked for me!)

cd ~  # we pointed TLS_CA_FILE at ~/cert.pem in the config file
openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 9999 -nodes

4. Write an Email

In a text file:

To: someone.in.the.world@some_website.com
From: "Kool Aid Man" <your.email@gmail.com>
Subject: Kudos!
MIME-Version: 1.0
Content-Type: text/plain

If you're reading this, I successfully sent you an email from the command line.

5. Test It Out

sendmail -i -t < test.txt 

Read my source material for more info. Check this out for more info on the openssl command.