ADMIN

Features
Icinga
Figure 2: Everything is working, but the NRPE plugin is causing problems.
monitoring environments, notification
escalation, and check schedules.
Icinga differentiates between active
and passive checks. Active checks are
initiated by the Icinga service and run
at times specified by the administrator.
For a passive check, an external
application does the work and forwards
the results to the Icinga server,
which is useful if you can’t actively
check the computer (e.g., it resides
behind a firewall). A large number of
plugins [4] already exist for various
styles in Nagios and Icinga. But before
the first check, the administrator
needs to configure the computers and
the services to monitor in Icinga.
The individual elements involved in
a check are referred to as objects in
Icinga. Objects include hosts, services,
contacts, commands, and time
slots. To facilitate daily work, you can
group hosts, services, and contacts.
The individual objects are defined in
CFG files, which reside below Icinga’s
etc/objects directory. The network
monitor includes a number of sample
definitions of various objects that adexternally
about CPU load, RAM, or
disk space usage, you need to install
a verbose add-on, such as NRPE
[3], on each machine. The remote
Icinga server will tell it to execute
the plugins on the local machine and
transmit the required information.
Icinga sends the system administrator
all the information needed and alerts
the admin of emergencies. Advanced
features that are a genuine help in
daily work include groups, redundant
Listing 3: commands.cfg (Excerpt)
01 # 'notify‐service‐by‐email' command definition
02 define command{
03 command_name notify‐service‐by‐email
04 command_line /usr/bin/printf "%b" "***** Icinga *****\n\nNotification Type: $NOTIFICATIONTYPE$\n\nService:
$SERVICEDESC$\nHost: $HOSTALIAS$\nAddress: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time:
$LONGDATETIME$\n\nAdditional Info:\n\n$SERVICEOUTPUT$" |
/usr/bin/mail ‐s "**$NOTIFICATIONTYPE$ Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTA
05 TE$ **" $CONTACTEMAIL$
06 }
07
08 # 'check‐host‐alive' command definition
09 define command{
10 command_name check‐host‐alive
11 command_line $USER1$/check_ping ‐H $HOSTADDRESS$ ‐w 3000.0,80% ‐c 5000.0,100% ‐p
12 5
13 }
Listing 4: timeperiods.cfg (Excerpt)
01 define timeperiod{
02 timeperiod_name 24x7
03 alias 24 Hours A Day, 7 Days A Week
04 sunday 00:00‐24:00
05 monday 00:00‐24:00
06 tuesday 00:00‐24:00
07 wednesday 00:00‐24:00
08 thursday 00:00‐24:00
09 friday 00:00‐24:00
10 saturday 00:00‐24:00
11 }
12
13 define timeperiod{
14 timeperiod_name wochentags
15 alias Robot Robot
16 monday 07:00‐17:00
17 tuesday 07:00‐17:00
18 wednesday 07:00‐17:00
19 thursday 07:00‐17:00
20 friday 07:00‐17:00
21 }
16 Admin 01 www.admin-magazine.com