How to change mail sent from in Nagios on Debian
GNU/Linux 6
I've been playing with configuring a new nagios running on a Linux
host which's aim is to monitor few Windows servers.
The Linux host's exim is configured to act as relay host to another
SMTP server, so all email ending up in the Linux localhost on port
25 is forwarded to the remote SMTP.
The remote smtp only allows the Linux to send email only in case if
a real existing
username@theserverhostname.com is passed it,
otherwise it rejects mail and does not sent properly the
email.
As the newly configured Nagios installatio is supposed to do e-mail
notification, I was looking for a way to change the default user
with which Nagios sends mails, which is inherited directly after
the username with which
/usr/sbin/nagios3 and
/usr/sbin/nrpe are running (on Debian this is
nagios@theserverhostname.com).
Thanksfully, there is a work around, I've red some forum threads
explaning that the username with whch nagios sends mail can be
easily changed from
/etc/nagios3/commands.cfg by passing the
-a "From: custom_user@myserverhostname.com" to all occurance
of
/usr/bin/mail -s , its preferrable that the
-a
custom_user@myserverhostname.com is inserted before the -s ""
subject option. Hence the occurance of
mail command should
be changed from:
| /usr/bin/mail -s "** $NOTIFICATIONTYPE$
To:
| /usr/bin/mail -a "From: custom_user@theserverhostname.com"
-s "** $NOTIFICATIONTYPE$
Now to read it's new configurations nagios requirs restart:
debian:~# /etc/init.d/nagios3 restart
...
Now in case of failed services or Hosts Down nagios will send it's
mail from the custom user
custom_user@theserverhostname.com
and nagios can can send mail properly via the remote relay SMTP
host ;)