Unsophisticated Alerts on Container Update Failures

By chimo on (updated on )

A couple of days ago, I mentioned:

[...]one thing I want to add now is error reporting for those unattended, scheduled upgrades. For this particular case, it would be as simple as flagging when `apk upgrade` returns a failure.

Not sure if this is worth a blog post but for now, I'm just sending myself email notifications via msmtp's `sendmail` implementation.

Basically, I just wrote a small `notify` method, which sends an email. Then, I wedged it in a couple of places in my update-containers.sh, which is run by `cron`. The method looks something like this: 

function notify() {
    msg="${1}"

    {
        echo From: cron@chromic.org
        echo To: chimo@chromic.org
        echo Subject: Cron failure
        echo
        echo "${msg}"
    } | sendmail -t -C /home/chimo/.msmtprc
}

This is temporary (famous last words and all) until I have time to implement something better (e.g.: send the contents of stderr via email when script exits with non-zero status, effectively decoupling notifications from the script itself. Or something, idk, we'll see).