Icinga 2 Tutorial
=================

:keywords:	Icinga, documentation, installation, configuration, tutorial
:description:	Quick introduction to monitoring network services with Icinga 2

Preface
-------

This tutorial is a step-by-step introduction to installing Icinga 2 and setting
up your first couple of service checks. It assumes some familiarity with Icinga 1.x.

Installation
------------

In order to get started with Icinga 2 we will have to install it. The preferred way
of doing this is to use the official Debian or RPM packages depending on which Linux
distribution you are running.

|===
|Distribution          | Package URL
|Debian                | http://icingabuild.dus.dg-i.net:8080/job/icinga2/
|RHEL                  | TBD
|===

In case you're running a distribution for which Icinga 2 packages are not yet available
you will have to check out the Icinga 2 Git repository from git://git.icinga.org/icinga2
and read the 'INSTALL' file.

By default Icinga 2 uses the following files and directories:

|===
|Path                   |Description
|/etc/icinga2           |Contains Icinga 2 configuration files.
|/etc/init.d/icinga2    |The Icinga 2 init script.
|/usr/share/doc/icinga2 |Documentation files that come with Icinga 2.
|/usr/share/icinga2/itl |The Icinga Template Library.
|/var/run/icinga2       |Command pipe and PID file.
|/var/cache/icinga2     |Performance data files and status.dat/objects.cache.
|/var/lib/icinga2       |The Icinga 2 state file.
|===

Our First Service Check
-----------------------

The Icinga 2 package comes with a number of example configuration files. However, in order
to explain some of the basics we're going write our own configuration file from scratch.

Start by creating the file /etc/icinga2/icinga2.conf with the following content:

----
include <itl/itl.conf>
include <itl/standalone.conf>

local object IcingaApplication "my-icinga" {
	macros["plugindir"] = "/usr/lib/nagios/plugins"
}
----

The configuration snippet includes the 'itl/itl.conf' and 'itl/standalone.conf' files
which are distributed as part of Icinga 2. We will discuss the Icinga Template Library (ITL)
in more detail later on.

The 'itl/standalone.conf' configuration file takes care of configuring Icinga 2 for
single-instance (i.e. non-clustered) mode.

Our configuration file also creates an object of type 'IcingaApplication' with the
name 'my-icinga'. The 'IcingaApplication' type can be used to define global macros and some
other global settings.

For now we're only defining the global macro 'plugindir' which we're going to use later on
when referring to the path which contains our check plugins. Depending on where you've installed
your check plugins you may need to update this path in your configuration file.

You can verify that your configuration file works by starting Icinga 2:

----
$ /usr/bin/icinga2 -c /etc/icinga2/icinga2.conf
[2013/04/23 13:36:20 +0200] <Main Thread> information/icinga-app: Icinga application loader (version: 0.0.1, git branch master, commit 0fcbfdb2)
[2013/04/23 13:36:20 +0200] <Main Thread> information/base: Adding library search dir: /usr/lib/icinga2
[2013/04/23 13:36:20 +0200] <Main Thread> information/base: Loading library 'libicinga.la'
[2013/04/23 13:36:20 +0200] <Main Thread> information/config: Adding include search dir: /usr/share/icinga2
[2013/04/23 13:36:20 +0200] <Main Thread> information/config: Compiling config file: /etc/icinga2/icinga2.conf
[2013/04/23 13:36:20 +0200] <Main Thread> information/config: Linking config items...
[2013/04/23 13:36:20 +0200] <Main Thread> information/config: Validating config items...
[2013/04/23 13:36:20 +0200] <Main Thread> information/config: Activating config items in compilation unit 'b2d21c28-a2e8-4fcb-ba00-45646bc1afb9'
[2013/04/23 13:36:20 +0200] <Main Thread> information/base: Restoring program state from file '/var/lib/icinga2/icinga2.state'
[2013/04/23 13:36:20 +0200] <Main Thread> information/base: Restored 0 objects
----

In case there are any configuration errors Icinga 2 should print error messages
containing details about what went wrong.

You can stop Icinga 2 with Control-C:

----
^C
[2013/04/23 13:39:39 +0200] <TP 0x7f2e9070f500 Worker #0> information/base: Shutting down Icinga...
[2013/04/23 13:39:39 +0200] <TP 0x7f2e9070f500 Worker #0> information/base: Dumping program state to file '/var/lib/icinga2/icinga2.state'
[2013/04/23 13:39:39 +0200] <Main Thread> information/icinga: Icinga has shut down.
$
----

Icinga 2 automatically saves its current state every couple of minutes and when it's being shut down.

So far our Icinga 2 setup doesn't do much. Lets change that by setting up a service
check for localhost. Modify your 'icinga2.conf' configuration file by adding the following lines:

----
object CheckCommand "my-ping" inherits "plugin-check-command" {
	command = [
		"$plugindir$/check_ping",
		"-H", "$address$",
		"-w", "10,5%",
		"-c", "25,10%"
	]
}

template Service "my-ping" inherits "plugin-service" {
	check_command = "my-ping"
}

object Host "localhost" {
	display_name = "Home, sweet home!",

	services["ping"] = {
		templates = [ "my-ping" ]
	},

	macros = {
		address = "127.0.0.1"
	},

	check_interval = 10s,

	hostcheck = "ping"
}
----

We're defining a command object called "my-ping" which inherits from the
'plugin-check-command' template. The 'plugin-check-command' template is provided as part of
the Icinga Template Library and describes how checks are performed.
In the case of plugin-based services this means that the command specified by
the 'command' property is executed.

The 'command' property is an array or command-line arguments for the check
plugin. Alternatively you can specify the check command as a string.

The check command can make use of macros. Unlike in Icinga 1.x we have free-form
macros which means that users can choose arbitrary names for their macros.

By convention the following macros are usually used:

|===
|Macro       |Description
|plugindir   |The path of your check plugins.
|address     |The IPv4 address of the host.
|address6    |The IPv6 address of the host.
|===

Note that the 'my-ping' command object does not define a value for the 'address' macro. This
is perfectly fine as long as that macro is defined somewhere else (e.g. in the host).

We're also defining a service template called 'my-ping' which uses the command object
we just created.

Next we're defining a 'Host' object called 'localhost'. We're setting an optional
display_name which is used by the Icinga Classic UI when showing that host in the host overview.

The services dictionary defines which services belong to a host. Using the [] indexing
operator we can manipulate individual items in this dictionary. In this case we're creating
a new service called 'ping'.

The templates array inside the service definition lists all the templates we want to use
for this particular service. For now we're just listing our 'my-ping' template.

Remember how we used the 'address' macro in the 'command' setting earlier? Now we're
defining a value for this macro which is used for all services and their commands which belong
to the 'localhost' Host object.

We're also setting the check_interval for all services belonging to this host to
10 seconds.

NOTE: When you don't specify an explicit time unit Icinga 2 automatically assumes that
you meant seconds.

And finally we're specifying which of the services we've created before is used to define
the host's state. Note that unlike in Icinga 1.x this just "clones" the service's state
and does not cause any additional checks to be performed.

Setting up the Icinga 1.x Classic UI
------------------------------------

Icinga 2 can write status.dat and objects.cache files in the format that is supported
by the Icinga 1.x Classic UI. External commands (a.k.a. the "command pipe") are also supported.
If you require the icinga.log for history views and/or reporting in Classic UI, this can be
added seperately to the CompatComponent object definition by adding a CompatLog object.

In order to enable this feature you will need to load the library 'compat' by adding the following lines
to your configuration file:

----
library "compat"

local object CompatComponent "compat" { }
local object CompatLog "my-log" { }
----

After restarting Icinga 2 you should be able to find the status.dat and objects.cache files in
/var/cache/icinga2. The log files can be found in /var/log/icinga2/compat. The command pipe can
be found in /var/run/icinga2.

You can install the Icinga 1.x Classic UI in standalone mode using the following commands:

----
$ wget http://downloads.sourceforge.net/project/icinga/icinga/1.9.0/icinga-1.9.0.tar.gz
$ tar xzf icinga-1.9.0.tar.gz ; cd icinga-1.9.0
$ ./configure --enable-classicui-standalone --prefix=/usr/local/icinga2-classicui
$ make classicui-standalone
$ sudo make install classicui-standalone install-webconf-auth
$ sudo service apache2 restart
----

NOTE: A detailed guide on installing Icinga 1.x Classic UI Standalone can be found on the Icinga Wiki
here: https://wiki.icinga.org/display/howtos/Setting+up+Icinga+Classic+UI+Standalone

After installing the Classic UI you will need to update the following settings in your cgi.cfg
configuration file at the bottom (section "STANDALONE (ICINGA 2) OPTIONS"):

|===
|Configuration Setting    | Value
|object_cache_file        | /var/cache/icinga2/objects.cache
|status_file              | /var/cache/icinga2/status.dat
|resource_file            | -
|command_file             | /var/run/icinga2/icinga2.cmd
|check_external_commands  | 1
|interval_length          | 60
|status_update_interval   | 10
|log_file                 | /var/log/icinga2/compat/icinga.log
|log_rotation_method      | h
|log_archive_path         | /var/log/icinga2/compat/archives
|date_format              | us
|===

Depending on how you installed Icinga 2 some of those paths and options might be different.

NOTE: You need to grant permissions for the apache user manually after starting Icinga 2 for now.
----
# chmod o+rwx /var/run/icinga2/{icinga2.cmd,livestatus}
----

Verify that your Icinga 1.x Classic UI works by browsing to your Classic UI installation URL e.g. http://localhost/icinga

Some More Templates
-------------------

Now that we've got our basic monitoring setup as well as the Icinga 1.x Classic UI to work
we can define a second host. Add the following lines to your configuration file:

----
object Host "icinga.org" {
	display_name = "Icinga Website",

	services["ping"] = {
		templates = [ "my-ping" ]
	},

	macros = {
		address = "www.icinga.org"
	},

	check_interval = 10s,

	hostcheck = "ping"
}
----

Restart your Icinga 2 instance and check the Classic UI for your new service's state. Unless
you have a low-latency network connection you will note that the service's state is 'CRITICAL'.
This is because in the 'my-ping' command object we have hard-coded the timeout as 25 milliseconds.

Ideally we'd be able to specify different timeouts for our new service. Using macros we
can easily do this.

NOTE: If you've used Icinga 1.x before you're probably familiar with doing this by passing
ARGx macros to your check commands.

Start by replacing your 'my-ping' command object with this:

----
object CheckCommand "my-ping" inherits "plugin-check-command" {
	command = [
		"$plugindir$/check_ping",
		"-H", "$address$",
		"-w", "$wrta$,$wpl$%",
		"-c", "$crta$,$cpl$%"
	],

	macros = {
		wrta = 10,
		wpl = 5,

		crta = 25,
		cpl = 10
	}
}
----

We have replaced our hard-coded timeout values with macros and we're providing default
values for these same macros right in the template definition. The object inherits the
basic check command attributes from the ITL provided template 'plugin-check-command'.

In order to oderride some of these macros for a specific host we need to update our
'icinga.org' host definition like this:

----
object Host "icinga.org" {
	display_name = "Icinga Website",

	services["ping"] = {
		templates = [ "my-ping" ],

		macros += {
			wrta = 100,
			crta = 250
		}
	},

	macros = {
		address = "www.icinga.org"
	},

	check_interval = 10s,

	hostcheck = "ping"
}
----

The '+=' operator allows us to selectively add new key-value pairs to an existing
dictionary. If we were to use the '=' operator instead we would have to provide
values for all the macros that are used in the 'my-ping' template overriding all
values there.

Icinga Template Library
-----------------------

The Icinga Template Library is a collection of configuration templates for commonly
used services. By default it is installed in '/usr/share/icinga2/itl' and you can include
it in your configuration files using the include directive:

----
include <itl/itl.conf>
----

NOTE: Ordinarily you'd use double-quotes for the include path. This way only paths
relative to the current configuration file are considered. The angle brackets tell
Icinga 2 to search its list of global include directories.

One of the templates in the ITL is the 'ping4' service template which is quite similar
to our example objects:

----
object CheckCommand "ping4" inherits "plugin-check-command" {
	command = [
		"$plugindir$/check_ping",
		"-4",
		"-H", "$address$",
		"-w", "$wrta$,$wpl$%",
		"-c", "$crta$,$cpl$%",
		"-p", "$packets$",
		"-t", "$timeout$"
	],

	macros = {
		wrta = 100,
		wpl = 5,

		crta = 200,
		cpl = 15,

		packets = 5,
		timeout = 0
	}
}

template Service "ping4" {
	check_command = "ping4"
}
----

Lets simplify our configuration file by removing our custom 'my-ping' template and
updating our service definitions to use the 'ping4' template instead.

Include Files
-------------

So far we've been using just one configuration file. However, once you've created a
few more host objects and service templates this can get rather confusing.

Icinga 2 lets you include other files from your configuration file. We can use this
feature to make our configuration a bit more modular and easier to understand.

Lets start by moving our two 'Host' objects to a separate configuration file: hosts.conf

We will also need to tell Icinga 2 that it should include our newly created configuration
file when parsing the main configuration file. This can be done by adding the include
directive to our 'icinga2.conf' file:

----
include "hosts.conf"
----

Depending on the number of hosts you have it might be useful to split your configuration
files based on other criteria (e.g. device type, location, etc.).

You can use wildcards in the include path in order to refer to multiple files. Assuming
you're keeping your host configuration files in a directory called 'hosts' you could include
them like this:

----
include "hosts/*.conf"
----

Notifications
-------------

Icinga 2 can send you notifications when your services change state. In order to do this
we're going to write a shell script in '/etc/icinga2/mail-notification.sh' that sends
e-mail based notifications:

----
#!/bin/sh

if [ -z "$1" ]; then
	echo "Syntax: $0 <e-mail>"
	echo
	echo "Sends a mail notification to the specified e-mail address."
	exit 1
fi

mail -s "** $NOTIFICATIONTYPE Service Alert: $HOSTALIAS/$SERVICEDESC is $SERVICESTATE **" $1 <<TEXT
***** Icinga *****

Notification Type: $NOTIFICATIONTYPE

Service: $SERVICEDESC
Host: $HOSTALIAS
Address: $address
State: $SERVICESTATE

Date/Time: $LONGDATETIME

Additional Info:

$SERVICEOUTPUT
TEXT

exit 0
----

Our shell script uses a couple of pre-defined macros (e.g. SERVICEDESC, HOSTALIAS, etc.)
that are always available.

Next we're going to create a 'Notification' template which tells Icinga how to invoke
the shell script:

----
object NotificationCommand "mail-notification" inherits "plugin-notification-command" {
	command = [
		"/etc/icinga2/mail-notification.sh",
		"$email$"
	],

	export_macros = [
		"NOTIFICATIONTYPE",
		"HOSTALIAS",
		"SERVICEDESC",
		"SERVICESTATE",
		"SERVICEDESC",
		"address",
		"LONGDATETIME",
		"SERVICEOUTPUT"
	]
}

template Notification "mail-notification" {
	notification_command = "mail-notification"
}
----

NOTE: Rather than adding these templates to your main configuration file you might want
to create a separate file, e.g. 'notifications.conf' and include it in 'icinga2.conf'.

The 'export_macros' property tells Icinga which macros to export into the
environment for the notification script.

We also need to create a 'User' object which Icinga can use to send notifications
to specific people:

----
object User "tutorial-user" {
	display_name = "Some User",

	macros = {
		email = "tutorial@example.org"
	}
}
----

Each time a notification is sent for a service the user's macros are used when
resolving the macros we used in the 'Notification' template.

In the next step we're going to create a 'Service' template which specifies
who notifications should be sent to:

----
template Service "mail-notification-service" {
	notifications["mail"] = {
		templates = [ "mail-notification" ],

		users = [ "tutorial-user" ]
	},

	notification_interval = 1m
}
----

And finally we can assign this new service template to our services:

----
	...
	services["ping"] = {
		templates = [ "ping4", "mail-notification-service" ]
	},
	...
----

In addition to defining notifications for individual services it is also possible
to assign notification templates to all services of a host. You can find more
information about how to do that in the documentation.

NOTE: Escalations in Icinga 2 are just a notification, only added a defined begin and end time.
Check the documentation for details.

Time Periods
------------

Time periods allow you to specify when certain services should be checked and when notifications
should be sent.

Here is an example time period definition:

----
object TimePeriod "work-hours" inherits "legacy-timeperiod" {
	ranges = {
		monday = "9:00-17:00",
		tuesday = "9:00-17:00",
		wednesday = "9:00-17:00",
		thursday = "9:00-17:00",
		friday = "9:00-17:00",
	}
}
----

The 'legacy-timeperiod' template is defined in the Icinga Template Library and supports Icinga 1.x
time periods. A complete definition of the time Icinga 1.x time period syntax can be found at
http://docs.icinga.org/latest/en/objectdefinitions.html#timeperiod.

Using the 'check_period' attribute you can define when services should be checked:

----
	...
	services["ping"] = {
		templates = [ "ping4", "mail-notification-service" ],
		check_period = "work-hours"
	},
	...
----

Also, using the 'notification_period' attribute you can define when notifications should be sent:

----
template Service "mail-notification-service" {
	notifications["mail"] = {
		templates = [ "mail-notification" ],

		users = [ "tutorial-user" ]
	},

	notification_interval = 1m,
	notification_period = "work-hours"
}
----

The 'notification_period' attribute is also valid in 'User' and 'Notification' objects.

Dependencies
------------

If you are familiar with Icinga 1.x host/service dependencies and parent/child relations on hosts,
you might want to look at the conversion script in order to convert your existing configuration. There are
no separate dependency objects anymore, and no separate parent attribute either.

Using Icinga 2, we can directly define a dependency in the current host or service object to any other
host or service object. If we want other objects to inherit those dependency attributes, we can also
define them in a template.

In the following example we've added a cluster host with the service 'ping' which we are going to define
a dependency for in another host.

----
template Service "my-cluster-ping" {
	check_command = "my-ping",
}

object Host "my-cluster" {
	...
	services["ping"] = {
		templates = [ "my-cluster-ping" ],
	}
	...
}
----

We can now define a service dependency as new service template (or directly on the service definition):

----
template Service "my-cluster-dependency" {
        servicedependencies = [
                { host = "my-cluster", service = "ping" },
        ],
}
----

Now let's use that template for the 'ping' service we've defined previously and assign the servicedependencies
to that service.

----
        ...
        services["ping"] = {
                templates = [ "ping4", "mail-notification-service", "my-cluster-dependency" ],
        },
        ...
----



Performance Data
----------------

Because there are no host checks in Icinga 2, the PerfdataWriter object will only write service
performance data files. Creating the object will allow you to set the perfdata_path, format_template and rotation_interval.
The format template is similar to existing Icinga 1.x configuration for PNP or inGraph using macro formatted strings.

Details on the common Icinga 1.x macros can be found at http://docs.icinga.org/latest/en/macrolist.html

NOTE: You can define multiple PerfdataWriter objects with different configuration settings, i.e. one for PNP, one for inGraph
or your preferred graphite collector.

Let's create a new PNP PerfdataWriter object:

----
local object PerfdataWriter "pnp" {
        perfdata_path = "/var/lib/icinga2/service-perfdata",
        format_template = "DATATYPE::SERVICEPERFDATA\tTIMET::$TIMET$\tHOSTNAME::$HOSTNAME$\tSERVICEDESC::$SERVICEDESC$\tSERVICEPERFDATA::$SERVICEPERFDATA$\tSERVICECHECKCOMMAND::$SERVICECHECKCOMMAND$\tHOSTSTATE::$HOSTSTATE$\tHOSTSTATETYPE::$HOSTSTATETYPE$\tSERVICESTATE::$SERVICESTATE$\tSERVICESTATETYPE::$SERVICESTATETYPE$",
        rotation_interval = 15s,
}
----

You may need to reconfigure your NPCD daemon with the correct path for your performance data files. This can
be done in the PNP configuration file npcd.cfg:

----
perfdata_spool_dir = /var/lib/icinga2/
----

Livestatus Component
--------------------

The Livestatus component will provide access to Icinga 2 using the livestatus api. In addition to the unix socket Icinga 2
also service livestatus directly via tcp socket.

NOTE: Only config and status tables are available at this time. History tables such as log, statehist will follow.

Once Icinga 2 is started, configure your gui (e.g. Thruk) using the livestatus backend.

TCP Socket
----
library "livestatus"
local object LivestatusComponent "livestatus-tcp" {
	socket_type = "tcp",
	host = "10.0.10.18",
	port = "6558"
}
----

Unix Socket
----
library "livestatus"
local object LivestatusComponent "livestatus-unix" {
	socket_type = "unix",
	socket_path = "/var/run/icinga2/livestatus"
}
----

NOTE: You need to grant permissions for the apache user manually after starting Icinga 2 for now.
----
# chmod o+rwx /var/run/icinga2/{icinga2.cmd,livestatus}
----



IDO Database Component
----------------------

The IDO component will write to the same database backend as known from Icinga 1.x IDOUtils. Therefore you'll
need to have your database schema and users already installed, like described in
http://docs.icinga.org/latest/en/quickstart-idoutils.html#createidoutilsdatabase

NOTE: Currently there's only MySQL support in progress, Postgresql, Oracle tbd.

Configure the IDO MySQL component with the defined credentials and start Icinga 2.

NOTE: Make sure to define a unique instance_name. That way the Icinga 2 IDO component will not interfere with your
Icinga 1.x setup, if existing.

----
library "ido_mysql"
local object IdoMysqlDbConnection "my-ido-mysql" {
	host = "127.0.0.1",
	port = "3306",
	user = "icinga",
	password = "icinga",
	database = "icinga",
	table_prefix = "icinga_",
	instance_name = "icinga2",
	instance_description = "icinga2 instance"
}
----

Starting Icinga 2 in debug mode in foreground using -x will show all database queries.


Custom Attributes
-----------------

In Icinga 1.x there were so-called "custom variables" available prefixed with an underscore, as well
as plenty of other attributes such as action_url, notes_url, icon_image, etc. To overcome the limitations
of hardcoded custom attributes, Icinga 2 ships with the 'custom' attribute as dictionary.

For example, if you have PNP installed we could add a reference url to Icinga Classic UI by using the classic
method of defining an action_url.

----
template Service "my-pnp-svc" {
	custom = {
		action_url = "/pnp4nagios/graph?host=$HOSTNAME$&srv=$SERVICEDESC$' class='tips' rel='/pnp4nagios/popup?host=$HOSTNAME$&srv=$SERVICEDESC$",
	}
}
----

And add that template again to our service definition:

----
        ...
        services["ping"] = {
                templates = [ "ping4", "mail-notification-service", "my-cluster-dependency", "my-pnp-svc" ],
        },
        ...
----

While at it, our configuration tool will add its LDAP DN and a snmp community to the service too, using += for
additive attributes:

----
        ...
        services["ping"] = {
                templates = [ "ping4", "mail-notification-service", "my-cluster-dependency", "my-pnp-svc" ],
		custom += {
			DN = "cn=icinga2-dev-svc,ou=icinga,ou=main,ou=IcingaConfig,ou=LConf,dc=icinga,dc=org",
			SNMPCOMMUNITY = "public"
		}
        },
        ...

----

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