get notification when systemd-monitored service enters failed state

Solution 1:

systemd units support OnFailure that will activate a unit (or more) when the unit goes to failed. You can put something like

 OnFailure=notify-failed@%n

And then create the [email protected] service where you can use the required specifier (you probably will want at least %i) to launch the script or command that will send notification.

You can see a practical example in http://northernlightlabs.se/systemd.status.mail.on.unit.failure

Solution 2:

Just my way to notify :

/etc/systemd/system/[email protected]

[Unit]
Description=Sent email 

[Service]
Type=oneshot
ExecStart=/usr/bin/bash -c '/usr/bin/systemctl status %i | /usr/bin/mailx -Ssendwait -s "[SYSTEMD_%i] Fail" [email protected]'

[Install]
WantedBy=multi-user.target

add to systemd:

systemctl enable /etc/systemd/system/[email protected]

At others services add:

[Unit]
OnFailure=notify-email@%i.service

Reload the configuration:

systemctl daemon-reload