.TH check_mk 1 "23. Juni 2008" "MKNagios 1.0.0" "User Commands"
.SH NAME
check_mk - check plugin and administration tool of MKNagios
.SH SYNOPSIS
.B check_mk
-d \fIHOST\fR
.br
.B check_mk
[\fIOPTION\fR]... \fIHOSTNAME\fR [\fIIPADDRESS\fR]
.br
.B check_mk
\-S|\-H
.br
.B check_mk
\-I \fITYPES\fR [\fIHOST1\fR \fIHOST2\fR ...]

.SH DESCRIPTION
.B check_mk
is the central tool for managing the configuration of MKNagios
as well as for performing the actual checks.
It is needed on the monitoring server only.

.B check_mk
has four different operation modes: \fITEST\fR, \fICHECK\fR, \fICONFIG\fR
and \fIINVENTORY\fR. 

.SH TEST MODE
The option \fI-d\fR selects test mode. The only argument in test mode
is the ip iaddress or host name of a monitoring target, which has installed
\fBmknagios\fR.

In test mode \fBcheck_mk\fR tries to connect to the mknagios-agent on
TCP port 6556 (or whatever port has been configured in \fBmknagios.cfg\fR).
It outputs all data it got from the agent verbatim to stdout. In fact it
is much the same as doing a "netcat HOST 5665".

.TP 4
\fIExamples\fR
check_mk -d xyhost123
.br
check_mk -d 10.20.0.117

.SH CHECK MODE
In check mode \fBcheck_mk\fR checks one of the hosts configured in 
the variable \fBall_hosts\fR in \fBmknagios.cfg\fR. Specify the name
of the host as argument to check_mk. If the hostname is not resolvable
via DNS then you have to specify the ip address as second argument.

If the data aquisition is successfull (either via TCP or via SNMP),
then all checks configured in \fBmknagios.cfg\fR are performed 
and the results are submitted to Nagios via passive service checks.

.TP 4
\fIExample 1:\fR check host with DNS lookup:
check_mk xyhost123

.TP
\fIExample 2:\fR check host wihtout DNS lookup:
check_mk xyhost123 10.0.11.18
.PP

Hint: When integrating into Nagios, \fBalways\fR provide an ip address.
A command definition should look like this:

.nf
define command {
    command_name   check-mk
    command_line   /usr/bin/check_mk $HOSTNAME$ $HOSTADDRESS$
}
.fi

.SH OPTIONS (CHECK MODE)
.TP
\fB\-v\fR, \fB\-\-verbose\fR
Verbose operation: Show steps of data aquisition, show results of checks
.TP
\fB\-p\fR
Also show performance data - only useful in combination with \fB\-v\fR.
.TP
\fB\-n\fR
Do \fBnot\fR submit check results to Nagios, just check. This option is
almays always used in combination with \fB\-v\fR (check_mk \-nv somehost)

.SH CONFIGURATION MODE
check_mk can create configuration data for Nagios for you. This is very
useful, especially for the configuration of the services. Configuration
output is selected via option \-S and/or \-H:

.TP
\fB-H\fR
Output host configuration suitable for Nagios for all hosts listed in
\fBall_hosts\fR. You might want to redirect stdout into a file lying 
within your object econfiguration directory of Nagios.

The host definitions for the refer to the template \fBmknagios-host\fR.
You have to define that template somewhere in your nagios configuration.
The value of \fBhost_groups\fR is set according to \fBall_hosts\fR.
The ip addresses of the hosts are computed automatically via DNS lookups.
.PP

\fIExample\fR: Let's assume your \fBall_hosts\fR in \fBmknagios.cfg\fR
looks like this:

.nf
all_hosts = [
  ("Heuberg",   "linux-servers"),
  ("SW18_F1",   "switches")
]
.fi

Then the output of \fBcheck_mk -H\fR will be:

.nf
define host {
    use            mknagios_host
    host_name      Heuberg
    alias          Heuberg
    host_groups    linux-servers
    address        10.10.1.4
}

define host {
    use            mknagios_host
    host_name      SW18_F1
    alias          SW18_F1
    host_groups    switches
    address        10.12.0.18
}
.fi

.TP
\fB-S\fR
Output service configuration to stdout.

For each host listed in \fBall_hosts\fR
one active service check is being output. For each check listed in \fBchecks\fR
one passive service check is being output. The service definitions each refer
to one of the following three templates, which you have to define manually
within your Nagios configuration:

.TP
mknagios_active
Active checks: The check_command must be \fBcheck-mk\fR with a definition
as previously shown in this man page.
.TP
mknagios_passive
Template for passive checks without performance data
.TP 
mknagios_passive_perf
Template for passive checks with performance data. Your definition of this
template should have \fBprocess_perf_data\fR set to \fB1\fR and should
have an \fBaction_url\fR (i.e. if you want to process performance data at all).

In addition to the service definitions there are output dummy commands 
for all different passive check types. That way you are able to determine
the check type in graphing tools like PNP4Nagios.

\fIExample\fR: Let's assume your \fBall_hosts\fR in \fBmknagios.cfg\fR
looks like this:

.nf
checks = [
  ("Heuberg", "df", "/",          (80, 90) ),
  ("Heuberg", "cpu.load", "5min", None ),
]
.fi

Then the output of \fBcheck_mk -H\fR will be:
.nf

define service {
    use                      mknagios_active
    host_name                Heuberg
    service_description      MK Nagios
    
}            

define service {
    use                      mknagios_passive_perf
    host_name                Heuberg
    service_description      fs_/
    check_command            mknagios-df
}

define service {
    use                      mknagios_passive_perf
    host_name                Heuberg
    service_description      CPU load 5min
    check_command            mknagios-cpu.load
}

define service {
    use                      mknagios_active
    host_name                SW18_F1
    service_description      MK Nagios
    
}            

define command {
    command_name             mknagios-df
    command_line             false
}

define command {
    command_name             mknagios-cpu.load
    command_line             false
}

.fi


.PP
You can combine \-S and \-H in order to have output all configuration data
at once, for example: 

\fBcheck_mk -SH > /etc/nagios/object/mknagios_data.cfg\fR.

.SH INVENTORY MODE
One of the key features of check_mk is its inventory funtionality.
It is selected by the option \fB\-I\fR. That option needs an argument:
one ore more comma separated check types, for that inventory should
be done. \fBcheck_mk \-I list\fR shows you a list of all check types
that support inventory.

As optional argument you can specify one or more hosts for which
inventory should be done. These hosts must be contained in \fBall_hosts\fR.
If you use \fB\-I\fR without hosts, all hosts in \fBall_hosts\fR will be
processed.

.TP
\fIExample 1:\fR Do inventory for df and md for all hosts:
check_mk -I df,md
.TP
\fIExample 2:\fR Do inventory for ipmi an hosts ab01f01 und ab01f02:
check_mk -I ipmi ab01f01 ab01f02
.PP
The inventory is looking for data items on hosts that are not yet
being checked (e.g. neu partitions, networks interfaces and so on).
For those items check configurations are created in a file in
the directory /etc/nagios/autochecks. You may edit those files
in order to change check parameters. The format of the tables
in those files is identical to the format of the variable \fBchecks\fR.

After an inventory found new checks, you need to update the
nagios configuration (see option \fB\-I\fR) and restart Nagios.

.SH MISC OPTIONS
.TP 
\-L
Output table of all available check types.