Nagios3 – Object Definitions

Introduction

One of the features of Nagios’ object configuration format is that you can create object definitions that inherit properties from other object definitions. An explanation of how object inheritance works can be found here. I strongly suggest that you familiarize yourself with object inheritance once you read over the documentation presented below, as it will make the job of creating and maintaining object definitions much easier than it otherwise would be. Also, read up on the object tricks that offer shortcuts for otherwise tedious configuration tasks.

When creating and/or editing configuration files, keep the following in mind:

1. Lines that start with a ‘#’ character are taken to be comments and are not processed
2. Directive names are case-sensitive
3. Characters that appear after a semicolon (;) in configuration lines are treated as comments and are not processed

Retention Notes

It is important to point out that several directives in host, service, and contact definitions may not be picked up by Nagios when you change them in your configuration files. Object directives that can exhibit this behavior are marked with an asterisk (*). The reason for this behavior is due to the fact that Nagios chooses to honor values stored in the state retention file over values found in the config files, assuming you have state retention enabled on a program-wide basis and the value of the directive is changed during runtime with an external command.

One way to get around this problem is to disable the retention of non-status information using the retain_nonstatus_information directive in the host, service, and contact definitions. Disabling this directive will cause Nagios to take the initial values for these directives from your config files, rather than from the state retention file when it (re)starts.

Sample Configuration Files

Note: Sample object configuration files are installed in the /usr/local/nagios/etc/ directory when you follow the quickstart installation guide.

File Inclusions, Cascading Configs, and the ’include_file’ Directive

An object definition file can include other object definition files with the use of the include_file=<file_name> and include_dir=<directory_name> directives. The former includes the single file specified, the latter will process all files ending in the .cfg extension in the directory specified. These directives may be repeated to include multiple files/directories. The directives are not allowed within the actual definition of an object, and should appear before, after, or in between any object definitions.

They are closely related to the cfg_file= and cfg_dir= directives in the main configuration file. These directives may be chained; e.g. an object definition file included from the main configuration file with a cfg_file= or cfg_dir= directive can use include_file= or include_dir= to include another object definition file, which in turn can also use include_file= or include_dir= to include yet another object definition file, and so on.

This can be useful when certain objects are dynamic but need to pull in a number of configs or when certain configs files grow to an unmanageable size.

Object Types

Host definitions
Host group definitions
Service definitions
Service group definitions
Contact definitions
Contact group definitions
Time period definitions
Command definitions
Service dependency definitions
Service escalation definitions
Host dependency definitions
Host escalation definitions
Extended host information definitions
Extended service information definitions

Host Definition

Description:

A host definition is used to define a physical server, workstation, device, etc. that resides on your network.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define host{
	host_name	host_name
	alias	alias
	display_name	display_name
	address	address
	parents	host_names
	hostgroups	hostgroup_names
	check_command	command_name
	initial_state	[o,d,u]
	max_check_attempts	#
	check_interval	#
	retry_interval	#
	active_checks_enabled	[0/1]
	passive_checks_enabled	[0/1]
	check_period	timeperiod_name
	obsess_over_host	[0/1]
	check_freshness	[0/1]
	freshness_threshold	#
	event_handler	command_name
	event_handler_enabled	[0/1]
	low_flap_threshold	#
	high_flap_threshold	#
	flap_detection_enabled	[0/1]
	flap_detection_options	[o,d,u]
	process_perf_data	[0/1]
	retain_status_information	[0/1]
	retain_nonstatus_information	[0/1]
	contacts	contacts
	contact_groups	contact_groups
	notification_interval	#
	first_notification_delay	#
	notification_period	timeperiod_name
	notification_options	[d,u,r,f,s]
	notifications_enabled	[0/1]
	stalking_options	[o,d,u]
	notes	note_string
	notes_url	url
	action_url	url
	icon_image	image_file
	icon_image_alt	alt_string
	vrml_image	image_file
	statusmap_image	image_file
	2d_coords	x_coord,y_coord
	3d_coords	x_coord,y_coord,z_coord
	}

Example Definition:

define host{
	host_name			bogus-router
	alias				Bogus Router #1
	address				192.168.1.254
	parents				server-backbone
	check_command			check-host-alive
	check_interval			5
	retry_interval			1
	max_check_attempts		5
	check_period			24x7
	process_perf_data		0
	retain_nonstatus_information	0
	contact_groups			router-admins
	notification_interval		30
	notification_period		24x7
	notification_options		d,u,r
	}

Directive Descriptions:

host_name:	This directive is used to define a short name used to identify the host. It is used in host group and service definitions to reference this particular host. Hosts can have multiple services (which are monitored) associated with them. When used properly, the $HOSTNAME$ macro will contain this short name.
alias:	This directive is used to define a longer name or description used to identify the host. It is provided in order to allow you to more easily identify a particular host. When used properly, the $HOSTALIAS$ macro will contain this alias/description.
address:	This directive is used to define the address of the host. Normally, this is an IP address, although it could really be anything you want (so long as it can be used to check the status of the host). You can use a FQDN to identify the host instead of an IP address, but if DNS services are not available this could cause problems. When used properly, the $HOSTADDRESS$ macro will contain this address. Note: If you do not specify an address directive in a host definition, the name of the host will be used as its address. A word of caution about doing this, however – if DNS fails, most of your service checks will fail because the plugins will be unable to resolve the host name.
display_name:	This directive is used to define an alternate name that should be displayed in the web interface for this host. If not specified, this defaults to the value you specify for the host_name directive. Note: The current CGIs do not use this option, although future versions of the web interface will.
parents:	This directive is used to define a comma-delimited list of short names of the “parent” hosts for this particular host. Parent hosts are typically routers, switches, firewalls, etc. that lie between the monitoring host and a remote hosts. A router, switch, etc. which is closest to the remote host is considered to be that host’s “parent”. Read the “Determining Status and Reachability of Network Hosts” document located here for more information. If this host is on the same network segment as the host doing the monitoring (without any intermediate routers, etc.) the host is considered to be on the local network and will not have a parent host. Leave this value blank if the host does not have a parent host (i.e. it is on the same segment as the Nagios host). The order in which you specify parent hosts has no effect on how things are monitored.
hostgroups:	This directive is used to identify the short name(s) of the hostgroup(s) that the host belongs to. Multiple hostgroups should be separated by commas. This directive may be used as an alternative to (or in addition to) using the members directive in hostgroup definitions.
check_command:	This directive is used to specify the short name of the command that should be used to check if the host is up or down. Typically, this command would try and ping the host to see if it is “alive”. The command must return a status of OK (0) or Nagios will assume the host is down. If you leave this argument blank, the host will not be actively checked. Thus, Nagios will likely always assume the host is up (it may show up as being in a “PENDING” state in the web interface). This is useful if you are monitoring printers or other devices that are frequently turned off. The maximum amount of time that the notification command can run is controlled by the host_check_timeout option.
initial_state:	By default Nagios will assume that all hosts are in UP states when it starts. You can override the initial state for a host by using this directive. Valid options are: o = UP, d = DOWN, and u = UNREACHABLE.
max_check_attempts:	This directive is used to define the number of times that Nagios will retry the host check command if it returns any state other than an OK state. Setting this value to 1 will cause Nagios to generate an alert without retrying the host check. Note: If you do not want to check the status of the host, you must still set this to a minimum value of 1. To bypass the host check, just leave the check_command option blank.
check_interval:	This directive is used to define the number of “time units” between regularly scheduled checks of the host. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. More information on this value can be found in the check scheduling documentation.
retry_interval:	This directive is used to define the number of “time units” to wait before scheduling a re-check of the hosts. Hosts are rescheduled at the retry interval when they have changed to a non-UP state. Once the host has been retried max_check_attempts times without a change in its status, it will revert to being scheduled at its “normal” rate as defined by the check_interval value. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. More information on this value can be found in the check scheduling documentation.
active_checks_enabled *:	This directive is used to determine whether or not active checks (either regularly scheduled or on-demand) of this host are enabled. Values: 0 = disable active host checks, 1 = enable active host checks (default).
passive_checks_enabled *:	This directive is used to determine whether or not passive checks are enabled for this host. Values: 0 = disable passive host checks, 1 = enable passive host checks (default).
check_period:	This directive is used to specify the short name of the time period during which active checks of this host can be made.
obsess_over_host *:	This directive determines whether or not checks for the host will be “obsessed” over using the ochp_command.
check_freshness *:	This directive is used to determine whether or not freshness checks are enabled for this host. Values: 0 = disable freshness checks, 1 = enable freshness checks (default).
freshness_threshold:	This directive is used to specify the freshness threshold (in seconds) for this host. If you set this directive to a value of 0, Nagios will determine a freshness threshold to use automatically.
event_handler:	This directive is used to specify the short name of the command that should be run whenever a change in the state of the host is detected (i.e. whenever it goes down or recovers). Read the documentation on event handlers for a more detailed explanation of how to write scripts for handling events. The maximum amount of time that the event handler command can run is controlled by the event_handler_timeout option.
event_handler_enabled *:	This directive is used to determine whether or not the event handler for this host is enabled. Values: 0 = disable host event handler, 1 = enable host event handler.
low_flap_threshold:	This directive is used to specify the low state change threshold used in flap detection for this host. More information on flap detection can be found here. If you set this directive to a value of 0, the program-wide value specified by the low_host_flap_threshold directive will be used.
high_flap_threshold:	This directive is used to specify the high state change threshold used in flap detection for this host. More information on flap detection can be found here. If you set this directive to a value of 0, the program-wide value specified by the high_host_flap_threshold directive will be used.
flap_detection_enabled *:	This directive is used to determine whether or not flap detection is enabled for this host. More information on flap detection can be found here. Values: 0 = disable host flap detection, 1 = enable host flap detection.
flap_detection_options:	This directive is used to determine what host states the flap detection logic will use for this host. Valid options are a combination of one or more of the following: o = UP states, d = DOWN states, u = UNREACHABLE states.
process_perf_data *:	This directive is used to determine whether or not the processing of performance data is enabled for this host. Values: 0 = disable performance data processing, 1 = enable performance data processing.
retain_status_information:	This directive is used to determine whether or not status-related information about the host is retained across program restarts. This is only useful if you have enabled state retention using the retain_state_information directive. Value: 0 = disable status information retention, 1 = enable status information retention.
retain_nonstatus_information:	This directive is used to determine whether or not non-status information about the host is retained across program restarts. This is only useful if you have enabled state retention using the retain_state_information directive. Value: 0 = disable non-status information retention, 1 = enable non-status information retention.
contacts:	This is a list of the short names of the contacts that should be notified whenever there are problems (or recoveries) with this host. Multiple contacts should be separated by commas. Useful if you want notifications to go to just a few people and don’t want to configure contact groups. You must specify at least one contact or contact group in each host definition.
contact_groups:	This is a list of the short names of the contact groups that should be notified whenever there are problems (or recoveries) with this host. Multiple contact groups should be separated by commas. You must specify at least one contact or contact group in each host definition.
notification_interval:	This directive is used to define the number of “time units” to wait before re-notifying a contact that this service is still down or unreachable. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. If you set this value to 0, Nagios will not re-notify contacts about problems for this host – only one problem notification will be sent out.
first_notification_delay:	This directive is used to define the number of “time units” to wait before sending out the first problem notification when this host enters a non-UP state. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. If you set this value to 0, Nagios will start sending out notifications immediately.
notification_period:	This directive is used to specify the short name of the time period during which notifications of events for this host can be sent out to contacts. If a host goes down, becomes unreachable, or recoveries during a time which is not covered by the time period, no notifications will be sent out.
notification_options:	This directive is used to determine when notifications for the host should be sent out. Valid options are a combination of one or more of the following: d = send notifications on a DOWN state, u = send notifications on an UNREACHABLE state, r = send notifications on recoveries (OK state), f = send notifications when the host starts and stops flapping, and s = send notifications when scheduled downtime starts and ends. If you specify n (none) as an option, no host notifications will be sent out. If you do not specify any notification options, Nagios will assume that you want notifications to be sent out for all possible states. Example: If you specify d,r in this field, notifications will only be sent out when the host goes DOWN and when it recovers from a DOWN state.
notifications_enabled *:	This directive is used to determine whether or not notifications for this host are enabled. Values: 0 = disable host notifications, 1 = enable host notifications.
stalking_options:	This directive determines which host states “stalking” is enabled for. Valid options are a combination of one or more of the following: o = stalk on UP states, d = stalk on DOWN states, and u = stalk on UNREACHABLE states. More information on state stalking can be found here.
notes:	This directive is used to define an optional string of notes pertaining to the host. If you specify a note here, you will see the it in the extended information CGI (when you are viewing information about the specified host).
notes_url:	This variable is used to define an optional URL that can be used to provide more information about the host. If you specify an URL, you will see a red folder icon in the CGIs (when you are viewing host information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/). This can be very useful if you want to make detailed information on the host, emergency contact methods, etc. available to other support staff.
action_url:	This directive is used to define an optional URL that can be used to provide more actions to be performed on the host. If you specify an URL, you will see a red “splat” icon in the CGIs (when you are viewing host information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/).
icon_image:	This variable is used to define the name of a GIF, PNG, or JPG image that should be associated with this host. This image will be displayed in the various places in the CGIs. The image will look best if it is 40×40 pixels in size. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
icon_image_alt:	This variable is used to define an optional string that is used in the ALT tag of the image specified by the <icon_image> argument.
vrml_image:	This variable is used to define the name of a GIF, PNG, or JPG image that should be associated with this host. This image will be used as the texture map for the specified host in the statuswrl CGI. Unlike the image you use for the <icon_image> variable, this one should probably not have any transparency. If it does, the host object will look a bit wierd. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
statusmap_image:	This variable is used to define the name of an image that should be associated with this host in the statusmap CGI. You can specify a JPEG, PNG, and GIF image if you want, although I would strongly suggest using a GD2 format image, as other image formats will result in a lot of wasted CPU time when the statusmap image is generated. GD2 images can be created from PNG images by using the pngtogd2 utility supplied with Thomas Boutell’s gd library. The GD2 images should be created in uncompressed format in order to minimize CPU load when the statusmap CGI is generating the network map image. The image will look best if it is 40×40 pixels in size. You can leave these option blank if you are not using the statusmap CGI. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
2d_coords:	This variable is used to define coordinates to use when drawing the host in the statusmap CGI. Coordinates should be given in positive integers, as they correspond to physical pixels in the generated image. The origin for drawing (0,0) is in the upper left hand corner of the image and extends in the positive x direction (to the right) along the top of the image and in the positive y direction (down) along the left hand side of the image. For reference, the size of the icons drawn is usually about 40×40 pixels (text takes a little extra space). The coordinates you specify here are for the upper left hand corner of the host icon that is drawn. Note: Don’t worry about what the maximum x and y coordinates that you can use are. The CGI will automatically calculate the maximum dimensions of the image it creates based on the largest x and y coordinates you specify.
3d_coords:	This variable is used to define coordinates to use when drawing the host in the statuswrl CGI. Coordinates can be positive or negative real numbers. The origin for drawing is (0.0,0.0,0.0). For reference, the size of the host cubes drawn is 0.5 units on each side (text takes a little more space). The coordinates you specify here are used as the center of the host cube.

Host Group Definition

Description:

A host group definition is used to group one or more hosts together for simplifying configuration with object tricks or display purposes in the CGIs.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define hostgroup{
	hostgroup_name	hostgroup_name
	alias	alias
	members	hosts
	hostgroup_members	hostgroups
	notes	note_string
	notes_url	url
	action_url	url
	}

Example Definition:

define hostgroup{
	hostgroup_name		novell-servers
	alias			Novell Servers
	members			netware1,netware2,netware3,netware4
	}

Directive Descriptions:

hostgroup_name:	This directive is used to define a short name used to identify the host group.
alias:	This directive is used to define is a longer name or description used to identify the host group. It is provided in order to allow you to more easily identify a particular host group.
members:	This is a list of the short names of hosts that should be included in this group. Multiple host names should be separated by commas. This directive may be used as an alternative to (or in addition to) the hostgroups directive in host definitions.
hostgroup_members:	This optional directive can be used to include hosts from other “sub” host groups in this host group. Specify a comma-delimited list of short names of other host groups whose members should be included in this group.
notes:	This directive is used to define an optional string of notes pertaining to the host. If you specify a note here, you will see the it in the extended information CGI (when you are viewing information about the specified host).
notes_url:	This variable is used to define an optional URL that can be used to provide more information about the host group. If you specify an URL, you will see a red folder icon in the CGIs (when you are viewing hostgroup information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/). This can be very useful if you want to make detailed information on the host group, emergency contact methods, etc. available to other support staff.
action_url:	This directive is used to define an optional URL that can be used to provide more actions to be performed on the host group. If you specify an URL, you will see a red “splat” icon in the CGIs (when you are viewing hostgroup information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/).

Service Definition

Description:

A service definition is used to identify a “service” that runs on a host. The term “service” is used very loosely. It can mean an actual service that runs on the host (POP, SMTP, HTTP, etc.) or some other type of metric associated with the host (response to a ping, number of logged in users, free disk space, etc.). The different arguments to a service definition are outlined below.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define service{
	host_name	host_name
	hostgroup_name	hostgroup_name
	service_description	service_description
	display_name	display_name
	servicegroups	servicegroup_names
	is_volatile	[0/1]
	check_command	command_name
	initial_state	[o,w,u,c]
	max_check_attempts	#
	check_interval	#
	retry_interval	#
	active_checks_enabled	[0/1]
	passive_checks_enabled	[0/1]
	check_period	timeperiod_name
	obsess_over_service	[0/1]
	check_freshness	[0/1]
	freshness_threshold	#
	event_handler	command_name
	event_handler_enabled	[0/1]
	low_flap_threshold	#
	high_flap_threshold	#
	flap_detection_enabled	[0/1]
	flap_detection_options	[o,w,c,u]
	process_perf_data	[0/1]
	retain_status_information	[0/1]
	retain_nonstatus_information	[0/1]
	notification_interval	#
	first_notification_delay	#
	notification_period	timeperiod_name
	notification_options	[w,u,c,r,f,s]
	notifications_enabled	[0/1]
	contacts	contacts
	contact_groups	contact_groups
	stalking_options	[o,w,u,c]
	notes	note_string
	notes_url	url
	action_url	url
	icon_image	image_file
	icon_image_alt	alt_string
	}

Example Definition:

define service{
	host_name		linux-server
	service_description	check-disk-sda1
	check_command		check-disk!/dev/sda1
	max_check_attempts	5
	check_interval	5
	retry_interval	3
	check_period		24x7
	notification_interval	30
	notification_period	24x7
	notification_options	w,c,r
	contact_groups		linux-admins
	}

Directive Descriptions:

host_name:	This directive is used to specify the short name(s) of the host(s) that the service “runs” on or is associated with. Multiple hosts should be separated by commas.
hostgroup_name:	This directive is used to specify the short name(s) of the hostgroup(s) that the service “runs” on or is associated with. Multiple hostgroups should be separated by commas. The hostgroup_name may be used instead of, or in addition to, the host_name directive.
service_description;:	This directive is used to define the description of the service, which may contain spaces, dashes, and colons (semicolons, apostrophes, and quotation marks should be avoided). No two services associated with the same host can have the same description. Services are uniquely identified with their host_name and service_description directives.
display_name:	This directive is used to define an alternate name that should be displayed in the web interface for this service. If not specified, this defaults to the value you specify for the service_description directive. Note: The current CGIs do not use this option, although future versions of the web interface will.
servicegroups:	This directive is used to identify the short name(s) of the servicegroup(s) that the service belongs to. Multiple servicegroups should be separated by commas. This directive may be used as an alternative to using the members directive in servicegroup definitions.
is_volatile:	This directive is used to denote whether the service is “volatile”. Services are normally not volatile. More information on volatile service and how they differ from normal services can be found here. Value: 0 = service is not volatile, 1 = service is volatile.
check_command:	This directive is used to specify the short name of the command that Nagios will run in order to check the status of the service. The maximum amount of time that the service check command can run is controlled by the service_check_timeout option.
initial_state:	By default Nagios will assume that all services are in OK states when it starts. You can override the initial state for a service by using this directive. Valid options are: o = OK, w = WARNING, u = UNKNOWN, and c = CRITICAL.
max_check_attempts:	This directive is used to define the number of times that Nagios will retry the service check command if it returns any state other than an OK state. Setting this value to 1 will cause Nagios to generate an alert without retrying the service check again.
check_interval:	This directive is used to define the number of “time units” to wait before scheduling the next “regular” check of the service. “Regular” checks are those that occur when the service is in an OK state or when the service is in a non-OK state, but has already been rechecked max_check_attempts number of times. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. More information on this value can be found in the check scheduling documentation.
retry_interval:	This directive is used to define the number of “time units” to wait before scheduling a re-check of the service. Services are rescheduled at the retry interval when they have changed to a non-OK state. Once the service has been retried max_check_attempts times without a change in its status, it will revert to being scheduled at its “normal” rate as defined by the check_interval value. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. More information on this value can be found in the check scheduling documentation.
active_checks_enabled *:	This directive is used to determine whether or not active checks of this service are enabled. Values: 0 = disable active service checks, 1 = enable active service checks (default).
passive_checks_enabled *:	This directive is used to determine whether or not passive checks of this service are enabled. Values: 0 = disable passive service checks, 1 = enable passive service checks (default).
check_period:	This directive is used to specify the short name of the time period during which active checks of this service can be made.
obsess_over_service *:	This directive determines whether or not checks for the service will be “obsessed” over using the ocsp_command.
check_freshness *:	This directive is used to determine whether or not freshness checks are enabled for this service. Values: 0 = disable freshness checks, 1 = enable freshness checks (default).
freshness_threshold:	This directive is used to specify the freshness threshold (in seconds) for this service. If you set this directive to a value of 0, Nagios will determine a freshness threshold to use automatically.
event_handler:	This directive is used to specify the short name of the command that should be run whenever a change in the state of the service is detected (i.e. whenever it goes down or recovers). Read the documentation on event handlers for a more detailed explanation of how to write scripts for handling events. The maximum amount of time that the event handler command can run is controlled by the event_handler_timeout option.
event_handler_enabled *:	This directive is used to determine whether or not the event handler for this service is enabled. Values: 0 = disable service event handler, 1 = enable service event handler.
low_flap_threshold:	This directive is used to specify the low state change threshold used in flap detection for this service. More information on flap detection can be found here. If you set this directive to a value of 0, the program-wide value specified by the low_service_flap_threshold directive will be used.
high_flap_threshold:	This directive is used to specify the high state change threshold used in flap detection for this service. More information on flap detection can be found here. If you set this directive to a value of 0, the program-wide value specified by the high_service_flap_threshold directive will be used.
flap_detection_enabled *:	This directive is used to determine whether or not flap detection is enabled for this service. More information on flap detection can be found here. Values: 0 = disable service flap detection, 1 = enable service flap detection.
flap_detection_options:	This directive is used to determine what service states the flap detection logic will use for this service. Valid options are a combination of one or more of the following: o = OK states, w = WARNING states, c = CRITICAL states, u = UNKNOWN states.
process_perf_data *:	This directive is used to determine whether or not the processing of performance data is enabled for this service. Values: 0 = disable performance data processing, 1 = enable performance data processing.
retain_status_information:	This directive is used to determine whether or not status-related information about the service is retained across program restarts. This is only useful if you have enabled state retention using the retain_state_information directive. Value: 0 = disable status information retention, 1 = enable status information retention.
retain_nonstatus_information:	This directive is used to determine whether or not non-status information about the service is retained across program restarts. This is only useful if you have enabled state retention using the retain_state_information directive. Value: 0 = disable non-status information retention, 1 = enable non-status information retention.
notification_interval:	This directive is used to define the number of “time units” to wait before re-notifying a contact that this service is still in a non-OK state. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. If you set this value to 0, Nagios will not re-notify contacts about problems for this service – only one problem notification will be sent out.
first_notification_delay:	This directive is used to define the number of “time units” to wait before sending out the first problem notification when this service enters a non-OK state. Unless you’ve changed the interval_length directive from the default value of 60, this number will mean minutes. If you set this value to 0, Nagios will start sending out notifications immediately.
notification_period:	This directive is used to specify the short name of the time period during which notifications of events for this service can be sent out to contacts. No service notifications will be sent out during times which is not covered by the time period.
notification_options:	This directive is used to determine when notifications for the service should be sent out. Valid options are a combination of one or more of the following: w = send notifications on a WARNING state, u = send notifications on an UNKNOWN state, c = send notifications on a CRITICAL state, r = send notifications on recoveries (OK state), f = send notifications when the service starts and stops flapping, and s = send notifications when scheduled downtime starts and ends. If you specify n (none) as an option, no service notifications will be sent out. If you do not specify any notification options, Nagios will assume that you want notifications to be sent out for all possible states. Example: If you specify w,r in this field, notifications will only be sent out when the service goes into a WARNING state and when it recovers from a WARNING state.
notifications_enabled *:	This directive is used to determine whether or not notifications for this service are enabled. Values: 0 = disable service notifications, 1 = enable service notifications.
contacts:	This is a list of the short names of the contacts that should be notified whenever there are problems (or recoveries) with this service. Multiple contacts should be separated by commas. Useful if you want notifications to go to just a few people and don’t want to configure contact groups. You must specify at least one contact or contact group in each service definition.
contact_groups:	This is a list of the short names of the contact groups that should be notified whenever there are problems (or recoveries) with this service. Multiple contact groups should be separated by commas. You must specify at least one contact or contact group in each service definition.
stalking_options:	This directive determines which service states “stalking” is enabled for. Valid options are a combination of one or more of the following: o = stalk on OK states, w = stalk on WARNING states, u = stalk on UNKNOWN states, and c = stalk on CRITICAL states. More information on state stalking can be found here.
notes:	This directive is used to define an optional string of notes pertaining to the service. If you specify a note here, you will see the it in the extended information CGI (when you are viewing information about the specified service).
notes_url:	This directive is used to define an optional URL that can be used to provide more information about the service. If you specify an URL, you will see a red folder icon in the CGIs (when you are viewing service information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/). This can be very useful if you want to make detailed information on the service, emergency contact methods, etc. available to other support staff.
action_url:	This directive is used to define an optional URL that can be used to provide more actions to be performed on the service. If you specify an URL, you will see a red “splat” icon in the CGIs (when you are viewing service information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/).
icon_image:	This variable is used to define the name of a GIF, PNG, or JPG image that should be associated with this service. This image will be displayed in the status and extended information CGIs. The image will look best if it is 40×40 pixels in size. Images for services are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
icon_image_alt:	This variable is used to define an optional string that is used in the ALT tag of the image specified by the <icon_image> argument. The ALT tag is used in the status, extended information and statusmap CGIs.

Service Group Definition

Description:

A service group definition is used to group one or more services together for simplifying configuration with object tricks or display purposes in the CGIs.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define servicegroup{
	servicegroup_name	servicegroup_name
	alias	alias
	members	services
	servicegroup_members	servicegroups
	notes	note_string
	notes_url	url
	action_url	url
	}

Example Definition:

define servicegroup{
	servicegroup_name	dbservices
	alias			Database Services
	members			ms1,SQL Server,ms1,SQL Server Agent,ms1,SQL DTC
	}

Directive Descriptions:

servicegroup_name:	This directive is used to define a short name used to identify the service group.
alias:	This directive is used to define is a longer name or description used to identify the service group. It is provided in order to allow you to more easily identify a particular service group.
members:	This is a list of the descriptions of services (and the names of their corresponding hosts) that should be included in this group. Host and service names should be separated by commas. This directive may be used as an alternative to the servicegroups directive in service definitions. The format of the member directive is as follows (note that a host name must precede a service name/description): members=<host1>,<service1>,<host2>,<service2>,…,<hostn>,<servicen>
servicegroup_members:	This optional directive can be used to include services from other “sub” service groups in this service group. Specify a comma-delimited list of short names of other service groups whose members should be included in this group.
notes:	This directive is used to define an optional string of notes pertaining to the service group. If you specify a note here, you will see the it in the extended information CGI (when you are viewing information about the specified service group).
notes_url:	This directive is used to define an optional URL that can be used to provide more information about the service group. If you specify an URL, you will see a red folder icon in the CGIs (when you are viewing service group information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/). This can be very useful if you want to make detailed information on the service group, emergency contact methods, etc. available to other support staff.
action_url:	This directive is used to define an optional URL that can be used to provide more actions to be performed on the service group. If you specify an URL, you will see a red “splat” icon in the CGIs (when you are viewing service group information) that links to the URL you specify here. Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/).

Contact Definition

Description:

A contact definition is used to identify someone who should be contacted in the event of a problem on your network. The different arguments to a contact definition are described below.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define contact{
	contact_name	contact_name
	alias	alias
	contactgroups	contactgroup_names
	host_notifications_enabled	[0/1]
	service_notifications_enabled	[0/1]
	host_notification_period	timeperiod_name
	service_notification_period	timeperiod_name
	host_notification_options	[d,u,r,f,s,n]
	service_notification_options	[w,u,c,r,f,s,n]
	host_notification_commands	command_name
	service_notification_commands	command_name
	email	email_address
	pager	pager_number or pager_email_gateway
	addressx	additional_contact_address
	can_submit_commands	[0/1]
	retain_status_information	[0/1]
	retain_nonstatus_information	[0/1]
	}

Example Definition:

define contact{
	contact_name                    jdoe
	alias                           John Doe
	host_notifications_enabled		1
	service_notifications_enabled	1
	service_notification_period     24x7
	host_notification_period        24x7
	service_notification_options    w,u,c,r
	host_notification_options       d,u,r
	service_notification_commands   notify-by-email
	host_notification_commands      host-notify-by-email
	email			jdoe@localhost.localdomain
	pager			555-5555@pagergateway.localhost.localdomain
	address1			xxxxx.xyyy@icq.com
	address2			555-555-5555
	can_submit_commands	1
	}

Directive Descriptions:

contact_name:	This directive is used to define a short name used to identify the contact. It is referenced in contact group definitions. Under the right circumstances, the $CONTACTNAME$ macro will contain this value.
alias:	This directive is used to define a longer name or description for the contact. Under the rights circumstances, the $CONTACTALIAS$ macro will contain this value. If not specified, the contact_name will be used as the alias.
contactgroups:	This directive is used to identify the short name(s) of the contactgroup(s) that the contact belongs to. Multiple contactgroups should be separated by commas. This directive may be used as an alternative to (or in addition to) using the members directive in contactgroup definitions.
host_notifications_enabled:	This directive is used to determine whether or not the contact will receive notifications about host problems and recoveries. Values: 0 = don’t send notifications, 1 = send notifications.
service_notifications_enabled:	This directive is used to determine whether or not the contact will receive notifications about service problems and recoveries. Values: 0 = don’t send notifications, 1 = send notifications.
host_notification_period:	This directive is used to specify the short name of the time period during which the contact can be notified about host problems or recoveries. You can think of this as an “on call” time for host notifications for the contact. Read the documentation on time periods for more information on how this works and potential problems that may result from improper use.
service_notification_period:	This directive is used to specify the short name of the time period during which the contact can be notified about service problems or recoveries. You can think of this as an “on call” time for service notifications for the contact. Read the documentation on time periods for more information on how this works and potential problems that may result from improper use.
host_notification_commands:	This directive is used to define a list of the short names of the commands used to notify the contact of a host problem or recovery. Multiple notification commands should be separated by commas. All notification commands are executed when the contact needs to be notified. The maximum amount of time that a notification command can run is controlled by the notification_timeout option.
host_notification_options:	This directive is used to define the host states for which notifications can be sent out to this contact. Valid options are a combination of one or more of the following: d = notify on DOWN host states, u = notify on UNREACHABLE host states, r = notify on host recoveries (UP states), f = notify when the host starts and stops flapping, and s = send notifications when host or service scheduled downtime starts and ends. If you specify n (none) as an option, the contact will not receive any type of host notifications.
service_notification_options:	This directive is used to define the service states for which notifications can be sent out to this contact. Valid options are a combination of one or more of the following: w = notify on WARNING service states, u = notify on UNKNOWN service states, c = notify on CRITICAL service states, r = notify on service recoveries (OK states), and f = notify when the service starts and stops flapping. If you specify n (none) as an option, the contact will not receive any type of service notifications.
service_notification_commands:	This directive is used to define a list of the short names of the commands used to notify the contact of a service problem or recovery. Multiple notification commands should be separated by commas. All notification commands are executed when the contact needs to be notified. The maximum amount of time that a notification command can run is controlled by the notification_timeout option.
email:	This directive is used to define an email address for the contact. Depending on how you configure your notification commands, it can be used to send out an alert email to the contact. Under the right circumstances, the $CONTACTEMAIL$ macro will contain this value.
pager:	This directive is used to define a pager number for the contact. It can also be an email address to a pager gateway (i.e. pagejoe@pagenet.com). Depending on how you configure your notification commands, it can be used to send out an alert page to the contact. Under the right circumstances, the $CONTACTPAGER$ macro will contain this value.
addressx:	Address directives are used to define additional “addresses” for the contact. These addresses can be anything – cell phone numbers, instant messaging addresses, etc. Depending on how you configure your notification commands, they can be used to send out an alert to the contact. Up to six addresses can be defined using these directives (address1 through address6). The $CONTACTADDRESSx$ macro will contain this value.
can_submit_commands:	This directive is used to determine whether or not the contact can submit external commands to Nagios from the CGIs. Values: 0 = don’t allow contact to submit commands, 1 = allow contact to submit commands.
retain_status_information:	This directive is used to determine whether or not status-related information about the contact is retained across program restarts. This is only useful if you have enabled state retention using the retain_state_information directive. Value: 0 = disable status information retention, 1 = enable status information retention.
retain_nonstatus_information:	This directive is used to determine whether or not non-status information about the contact is retained across program restarts. This is only useful if you have enabled state retention using the retain_state_information directive. Value: 0 = disable non-status information retention, 1 = enable non-status information retention.

Contact Group Definition

Description:

A contact group definition is used to group one or more contacts together for the purpose of sending out alert/recovery notifications.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define contactgroup{
	contactgroup_name	contactgroup_name
	alias	alias
	members	contacts
	contactgroup_members	contactgroups
	}

Example Definition:

define contactgroup{
	contactgroup_name		novell-admins
	alias			Novell Administrators
	members			jdoe,rtobert,tzach
	}

Directive Descriptions:

contactgroup_name:	This directive is a short name used to identify the contact group.
alias:	This directive is used to define a longer name or description used to identify the contact group.
members:	This optional directive is used to define a list of the short names of contacts that should be included in this group. Multiple contact names should be separated by commas. This directive may be used as an alternative to (or in addition to) using the contactgroups directive in contact definitions.
contactgroup_members:	This optional directive can be used to include contacts from other “sub” contact groups in this contact group. Specify a comma-delimited list of short names of other contact groups whose members should be included in this group.

Time Period Definition

Description:

A time period is a list of times during various days that are considered to be “valid” times for notifications and service checks. It consists of time ranges for each day of the week that “rotate” once the week has come to an end. Different types of exceptions to the normal weekly time are supported, including: specific weekdays, days of generic months, days of specific months, and calendar dates.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define timeperiod{
	timeperiod_name	timeperiod_name
	alias	alias
	[weekday]	timeranges
	[exception]	timeranges
	exclude	[timeperiod1,timeperiod2,…,timeperiodn]
	}

Example Definitions:

define timeperiod{
	timeperiod_name		nonworkhours
	alias			Non-Work Hours
	sunday			00:00-24:00			; Every Sunday of every week
	monday			00:00-09:00,17:00-24:00		; Every Monday of every week
	tuesday			00:00-09:00,17:00-24:00		; Every Tuesday of every week
	wednesday			00:00-09:00,17:00-24:00		; Every Wednesday of every week
	thursday			00:00-09:00,17:00-24:00		; Every Thursday of every week
	friday			00:00-09:00,17:00-24:00		; Every Friday of every week
	saturday			00:00-24:00			; Every Saturday of every week
	}
define timeperiod{
	timeperiod_name		misc-single-days
	alias			Misc Single Days
	1999-01-28		00:00-24:00 		; January 28th, 1999
	monday 3			00:00-24:00		; 3rd Monday of every month
	day 2			00:00-24:00		; 2nd day of every month
	february 10		00:00-24:00		; February 10th of every year
	february -1		00:00-24:00		; Last day in February of every year
	friday -2			00:00-24:00		; 2nd to last Friday of every month
	thursday -1 november	00:00-24:00		; Last Thursday in November of every year
	}

define timeperiod{
	timeperiod_name		misc-date-ranges
	alias			Misc Date Ranges
	2007-01-01 - 2008-02-01	00:00-24:00		; January 1st, 2007 to February 1st, 2008
	monday 3 - thursday 4	00:00-24:00		; 3rd Monday to 4th Thursday of every month
	day 1 - 15		00:00-24:00		; 1st to 15th day of every month
	day 20 - -1		00:00-24:00		; 20th to the last day of every month
	july 10 - 15		00:00-24:00		; July 10th to July 15th of every year
	april 10 - may 15		00:00-24:00		; April 10th to May 15th of every year
	tuesday 1 april - friday 2 may	00:00-24:00	; 1st Tuesday in April to 2nd Friday in May of every year
	}
define timeperiod{
	timeperiod_name		misc-skip-ranges
	alias			Misc Skip Ranges
	2007-01-01 - 2008-02-01 / 3		00:00-24:00	; Every 3 days from January 1st, 2007 to February 1st, 2008
	2008-04-01 / 7			00:00-24:00	; Every 7 days from April 1st, 2008 (continuing forever)
	monday 3 - thursday 4 / 2		00:00-24:00	; Every other day from 3rd Monday to 4th Thursday of every month
	day 1 - 15 / 5			00:00-24:00	; Every 5 days from the 1st to the 15th day of every month
	july 10 - 15 / 2			00:00-24:00	; Every other day from July 10th to July 15th of every year
	tuesday 1 april - friday 2 may / 6	00:00-24:00	; Every 6 days from the 1st Tuesday in April to the 2nd Friday in May of every year
	}

Directive Descriptions:

timeperiod_name:	This directives is the short name used to identify the time period.
alias:	This directive is a longer name or description used to identify the time period.
[weekday]:	The weekday directives (“sunday” through “saturday“)are comma-delimited lists of time ranges that are “valid” times for a particular day of the week. Notice that there are seven different days for which you can define time ranges (Sunday through Saturday). Each time range is in the form of HH:MM-HH:MM, where hours are specified on a 24 hour clock. For example, 00:15-24:00 means 12:15am in the morning for this day until 12:00am midnight (a 23 hour, 45 minute total time range). If you wish to exclude an entire day from the timeperiod, simply do not include it in the timeperiod definition.
[exception]:	You can specify several different types of exceptions to the standard rotating weekday schedule. Exceptions can take a number of different forms including single days of a specific or generic month, single weekdays in a month, or single calendar dates. You can also specify a range of days/dates and even specify skip intervals to obtain functionality described by “every 3 days between these dates”. Rather than list all the possible formats for exception strings, I’ll let you look at the example timeperiod definitions above to see what’s possible. 🙂 Weekdays and different types of exceptions all have different levels of precedence, so its important to understand how they can affect each other. More information on this can be found in the documentation on timeperiods.
exclude:	This directive is used to specify the short names of other timeperiod definitions whose time ranges should be excluded from this timeperiod. Multiple timeperiod names should be separated with a comma.

Command Definition

Description:

A command definition is just that. It defines a command. Commands that can be defined include service checks, service notifications, service event handlers, host checks, host notifications, and host event handlers. Command definitions can contain macros, but you must make sure that you include only those macros that are “valid” for the circumstances when the command will be used. More information on what macros are available and when they are “valid” can be found here. The different arguments to a command definition are outlined below.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define command{
	command_name	command_name
	command_line	command_line
	}

Example Definition:

define command{
	command_name	check_pop
	command_line	/usr/local/nagios/libexec/check_pop -H $HOSTADDRESS$
	}

Directive Descriptions:

command_name:

This directive is the short name used to identify the command. It is referenced in contact, host, and service definitions (in notification, check, and event handler directives), among other places.

command_line:

This directive is used to define what is actually executed by Nagios when the command is used for service or host checks, notifications, or event handlers. Before the command line is executed, all valid macros are replaced with their respective values. See the documentation on macros for determining when you can use different macros. Note that the command line is not surrounded in quotes. Also, if you want to pass a dollar sign ($) on the command line, you have to escape it with another dollar sign. NOTE: You may not include a semicolon (;) in the command_line directive, because everything after it will be ignored as a config file comment. You can work around this limitation by setting one of the $USER$ macros in your resource file to a semicolon and then referencing the appropriate $USER$ macro in the command_line directive in place of the semicolon. If you want to pass arguments to commands during runtime, you can use $ARGn$ macros in the command_line directive of the command definition and then separate individual arguments from the command name (and from each other) using bang (!) characters in the object definition directive (host check command, service event handler command, etc) that references the command. More information on how arguments in command definitions are processed during runtime can be found in the documentation on macros.

Service Dependency Definition

Description:

Service dependencies are an advanced feature of Nagios that allow you to suppress notifications and active checks of services based on the status of one or more other services. Service dependencies are optional and are mainly targeted at advanced users who have complicated monitoring setups. More information on how service dependencies work (read this!) can be found here.

Definition Format:

Note: Directives in red are required, while those in black are optional. However, you must supply at least one type of criteria for the definition to be of much use.

define servicedependency{
	dependent_host_name	host_name
	dependent_hostgroup_name	hostgroup_name
	servicegroup_name	servicegroup_name
	dependent_servicegroup_name	servicegroup_name
	dependent_service_description	service_description
	host_name	host_name
	hostgroup_name	hostgroup_name
	service_description	service_description
	inherits_parent	[0/1]
	execution_failure_criteria	[o,w,u,c,p,n]
	notification_failure_criteria	[o,w,u,c,p,n]
	dependency_period	timeperiod_name
	}

Example Definition:

define servicedependency{
	host_name			WWW1
	service_description		Apache Web Server
	dependent_host_name		WWW1
	dependent_service_description	Main Web Site
	execution_failure_criteria	n
	notification_failure_criteria	w,u,c
	}

Directive Descriptions:

dependent_host_name:	This directive is used to identify the short name(s) of the host(s) that the dependent service “runs” on or is associated with. Multiple hosts should be separated by commas. Leaving this directive blank can be used to create “same host” dependencies.
dependent_hostgroup_name:	This directive is used to specify the short name(s) of the hostgroup(s) that the dependent service “runs” on or is associated with. Multiple hostgroups should be separated by commas. The dependent_hostgroup may be used instead of, or in addition to, the dependent_host directive.
servicegroup_name:	This directive is used to specify the short name(s) of the servicegroup(s) that will inherit the dependency. Multiple servicegroups should be separated by commas.
dependent_servicegroup_name:	This directive is used to specify the short name(s) of the servicegroup(s) that the dependent service “runs” on or is associated with. Multiple servicegroups should be separated by commas.
dependent_service_description:	This directive is used to identify the description of the dependent service.
host_name:	This directive is used to identify the short name(s) of the host(s) that the service that is being depended upon (also referred to as the master service) “runs” on or is associated with. Multiple hosts should be separated by commas.
hostgroup_name:	This directive is used to identify the short name(s) of the hostgroup(s) that the service that is being depended upon (also referred to as the master service) “runs” on or is associated with. Multiple hostgroups should be separated by commas. The hostgroup_name may be used instead of, or in addition to, the host_name directive.
service_description:	This directive is used to identify the description of the service that is being depended upon (also referred to as the master service).
inherits_parent:	This directive indicates whether or not the dependency inherits dependencies of the service that is being depended upon (also referred to as the master service). In other words, if the master service is dependent upon other services and any one of those dependencies fail, this dependency will also fail.
execution_failure_criteria:	This directive is used to specify the criteria that determine when the dependent service should not be actively checked. If the master service is in one of the failure states we specify, the dependent service will not be actively checked. Valid options are a combination of one or more of the following (multiple options are separated with commas): o = fail on an OK state, w = fail on a WARNING state, u = fail on an UNKNOWN state, c = fail on a CRITICAL state, and p = fail on a pending state (e.g. the service has not yet been checked). If you specify n (none) as an option, the execution dependency will never fail and checks of the dependent service will always be actively checked (if other conditions allow for it to be). Example: If you specify o,c,u in this field, the dependent service will not be actively checked if the master service is in either an OK, a CRITICAL, or an UNKNOWN state.
notification_failure_criteria:	This directive is used to define the criteria that determine when notifications for the dependent service should not be sent out. If the master service is in one of the failure states we specify, notifications for the dependent service will not be sent to contacts. Valid options are a combination of one or more of the following: o = fail on an OK state, w = fail on a WARNING state, u = fail on an UNKNOWN state, c = fail on a CRITICAL state, and p = fail on a pending state (e.g. the service has not yet been checked). If you specify n (none) as an option, the notification dependency will never fail and notifications for the dependent service will always be sent out. Example: If you specify w in this field, the notifications for the dependent service will not be sent out if the master service is in a WARNING state.
dependency_period:	This directive is used to specify the short name of the time period during which this dependency is valid. If this directive is not specified, the dependency is considered to be valid during all times.

Service Escalation Definition

Description:

Service escalations are completely optional and are used to escalate notifications for a particular service. More information on how notification escalations work can be found here.

Definition Format:

Note: Directives in red are required, while those in black are optional. Optional directives, if left blank, will be inherited from the service object.

define serviceescalation{
	host_name	host_name
	hostgroup_name	hostgroup_name
	service_description	service_description
	contacts	contacts
	contact_groups	contactgroup_name
	first_notification	#
	last_notification	#
	notification_interval	#
	escalation_period	timeperiod_name
	escalation_options	[w,u,c,r]
	}

Example Definition:

define serviceescalation{
	host_name		nt-3
	service_description	Processor Load
	first_notification	4
	last_notification	0
	notification_interval	30
	contact_groups		all-nt-admins,themanagers
	}

Directive Descriptions:

host_name:	This directive is used to identify the short name(s) of the host(s) that the service escalation should apply to or is associated with.
hostgroup_name:	This directive is used to specify the short name(s) of the hostgroup(s) that the service escalation should apply to or is associated with. Multiple hostgroups should be separated by commas. The hostgroup_name may be used instead of, or in addition to, the host_name directive.
service_description:	This directive is used to identify the description of the service the escalation should apply to.
first_notification:	This directive is a number that identifies the first notification for which this escalation is effective. For instance, if you set this value to 3, this escalation will only be used if the service is in a non-OK state long enough for a third notification to go out.
last_notification:	This directive is a number that identifies the last notification for which this escalation is effective. For instance, if you set this value to 5, this escalation will not be used if more than five notifications are sent out for the service. Setting this value to 0 means to keep using this escalation entry forever (no matter how many notifications go out).
contacts:	This is a list of the short names of the contacts that should be notified whenever there are problems (or recoveries) with this service. Multiple contacts should be separated by commas. Useful if you want notifications to go to just a few people and don’t want to configure contact groups. You must specify at least one contact or contact group in each service escalation definition.
contact_groups:	This directive is used to identify the short name of the contact group that should be notified when the service notification is escalated. Multiple contact groups should be separated by commas. You must specify at least one contact or contact group in each service escalation definition.
notification_interval:	This directive is used to determine the interval at which notifications should be made while this escalation is valid. If you specify a value of 0 for the interval, Nagios will send the first notification when this escalation definition is valid, but will then prevent any more problem notifications from being sent out for the host. Notifications are only sent out when the host recovers. This is useful if you want to stop having notifications sent out after a certain amount of time. Note: If multiple escalation entries for a host overlap for one or more notification ranges, the smallest notification interval from all escalation entries is used.
escalation_period:	This directive is used to specify the short name of the time period during which this escalation is valid. If this directive is not specified, the escalation is considered to be valid during all times.
escalation_options:	This directive is used to define the criteria that determine when this service escalation is used. The escalation is used only if the service is in one of the states specified in this directive. If this directive is not specified in a service escalation, the escalation is considered to be valid during all service states. Valid options are a combination of one or more of the following: r = escalate on an OK (recovery) state, w = escalate on a WARNING state, u = escalate on an UNKNOWN state, and c = escalate on a CRITICAL state. Example: If you specify w in this field, the escalation will only be used if the service is in a WARNING state.

Host Dependency Definition

Description:

Host dependencies are an advanced feature of Nagios that allow you to suppress notifications for hosts based on the status of one or more other hosts. Host dependencies are optional and are mainly targeted at advanced users who have complicated monitoring setups. More information on how host dependencies work (read this!) can be found here.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define hostdependency{
	dependent_host_name	host_name
	dependent_hostgroup_name	hostgroup_name
	host_name	host_name
	hostgroup_name	hostgroup_name
	inherits_parent	[0/1]
	execution_failure_criteria	[o,d,u,p,n]
	notification_failure_criteria	[o,d,u,p,n]
	dependency_period	timeperiod_name
	}

Example Definition:

define hostdependency{
	host_name			WWW1
	dependent_host_name		DBASE1
	notification_failure_criteria	d,u
	}

Directive Descriptions:

dependent_host_name:	This directive is used to identify the short name(s) of the dependent host(s). Multiple hosts should be separated by commas.
dependent_hostgroup_name:	This directive is used to identify the short name(s) of the dependent hostgroup(s). Multiple hostgroups should be separated by commas. The dependent_hostgroup_name may be used instead of, or in addition to, the dependent_host_name directive.
host_name:	This directive is used to identify the short name(s) of the host(s) that is being depended upon (also referred to as the master host). Multiple hosts should be separated by commas.
hostgroup_name:	This directive is used to identify the short name(s) of the hostgroup(s) that is being depended upon (also referred to as the master host). Multiple hostgroups should be separated by commas. The hostgroup_name may be used instead of, or in addition to, the host_name directive.
inherits_parent:	This directive indicates whether or not the dependency inherits dependencies of the host that is being depended upon (also referred to as the master host). In other words, if the master host is dependent upon other hosts and any one of those dependencies fail, this dependency will also fail.
execution_failure_criteria:	This directive is used to specify the criteria that determine when the dependent host should not be actively checked. If the master host is in one of the failure states we specify, the dependent host will not be actively checked. Valid options are a combination of one or more of the following (multiple options are separated with commas): o = fail on an UP state, d = fail on a DOWN state, u = fail on an UNREACHABLE state, and p = fail on a pending state (e.g. the host has not yet been checked). If you specify n (none) as an option, the execution dependency will never fail and the dependent host will always be actively checked (if other conditions allow for it to be). Example: If you specify u,d in this field, the dependent host will not be actively checked if the master host is in either an UNREACHABLE or DOWN state.
notification_failure_criteria:	This directive is used to define the criteria that determine when notifications for the dependent host should not be sent out. If the master host is in one of the failure states we specify, notifications for the dependent host will not be sent to contacts. Valid options are a combination of one or more of the following: o = fail on an UP state, d = fail on a DOWN state, u = fail on an UNREACHABLE state, and p = fail on a pending state (e.g. the host has not yet been checked). If you specify n (none) as an option, the notification dependency will never fail and notifications for the dependent host will always be sent out. Example: If you specify d in this field, the notifications for the dependent host will not be sent out if the master host is in a DOWN state.
dependency_period:	This directive is used to specify the short name of the time period during which this dependency is valid. If this directive is not specified, the dependency is considered to be valid during all times.

Host Escalation Definition

Description:

Host escalations are completely optional and are used to escalate notifications for a particular host. More information on how notification escalations work can be found here.

Definition Format:

Note: Directives in red are required, while those in black are optional.

define hostescalation{
	host_name	host_name
	hostgroup_name	hostgroup_name
	contacts	contacts
	contact_groups	contactgroup_name
	first_notification	#
	last_notification	#
	notification_interval	#
	escalation_period	timeperiod_name
	escalation_options	[d,u,r]
	}

Example Definition:

define hostescalation{
	host_name		router-34
	first_notification	5
	last_notification	8
	notification_interval	60
	contact_groups		all-router-admins
	}

Directive Descriptions:

host_name:	This directive is used to identify the short name of the host that the escalation should apply to.
hostgroup_name:	This directive is used to identify the short name(s) of the hostgroup(s) that the escalation should apply to. Multiple hostgroups should be separated by commas. If this is used, the escalation will apply to all hosts that are members of the specified hostgroup(s).
first_notification:	This directive is a number that identifies the first notification for which this escalation is effective. For instance, if you set this value to 3, this escalation will only be used if the host is down or unreachable long enough for a third notification to go out.
last_notification:	This directive is a number that identifies the last notification for which this escalation is effective. For instance, if you set this value to 5, this escalation will not be used if more than five notifications are sent out for the host. Setting this value to 0 means to keep using this escalation entry forever (no matter how many notifications go out).
contacts:	This is a list of the short names of the contacts that should be notified whenever there are problems (or recoveries) with this host. Multiple contacts should be separated by commas. Useful if you want notifications to go to just a few people and don’t want to configure contact groups. You must specify at least one contact or contact group in each host escalation definition.
contact_groups:	This directive is used to identify the short name of the contact group that should be notified when the host notification is escalated. Multiple contact groups should be separated by commas. You must specify at least one contact or contact group in each host escalation definition.
notification_interval:	This directive is used to determine the interval at which notifications should be made while this escalation is valid. If you specify a value of 0 for the interval, Nagios will send the first notification when this escalation definition is valid, but will then prevent any more problem notifications from being sent out for the host. Notifications are only sent out when the host recovers. This is useful if you want to stop having notifications sent out after a certain amount of time. Note: If multiple escalation entries for a host overlap for one or more notification ranges, the smallest notification interval from all escalation entries is used.
escalation_period:	This directive is used to specify the short name of the time period during which this escalation is valid. If this directive is not specified, the escalation is considered to be valid during all times.
escalation_options:	This directive is used to define the criteria that determine when this host escalation is used. The escalation is used only if the host is in one of the states specified in this directive. If this directive is not specified in a host escalation, the escalation is considered to be valid during all host states. Valid options are a combination of one or more of the following: r = escalate on an UP (recovery) state, d = escalate on a DOWN state, and u = escalate on an UNREACHABLE state. Example: If you specify d in this field, the escalation will only be used if the host is in a DOWN state.

Extended Host Information Definition

Description:

Extended host information entries are basically used to make the output from the status, statusmap, statuswrl, and extinfo CGIs look pretty. They have no effect on monitoring and are completely optional.

Tip: As of Nagios 3.x, all directives contained in extended host information definitions are also available in host definitions. Thus, you can choose to define the directives below in your host definitions if it makes your configuration simpler. Separate extended host information definitions will continue to be supported for backward compatability.

Definition Format:

Note: Variables in red are required, while those in black are optional. However, you need to supply at least one optional variable in each definition for it to be of much use.

define hostextinfo{
	host_name	host_name
	notes	note_string
	notes_url	url
	action_url	url
	icon_image	image_file
	icon_image_alt	alt_string
	vrml_image	image_file
	statusmap_image	image_file
	2d_coords	x_coord,y_coord
	3d_coords	x_coord,y_coord,z_coord
	}

Example Definition:

define hostextinfo{
	host_name	netware1
	notes		This is the primary Netware file server
	notes_url	http://webserver.localhost.localdomain/hostinfo.pl?host=netware1
	icon_image	novell40.png 
	icon_image_alt	IntranetWare 4.11
	vrml_image	novell40.png
	statusmap_image	novell40.gd2
	2d_coords	100,250
	3d_coords	100.0,50.0,75.0
	}

Variable Descriptions:

host_name:	This variable is used to identify the short name of the host which the data is associated with.
notes:	This directive is used to define an optional string of notes pertaining to the host. If you specify a note here, you will see the it in the extended information CGI (when you are viewing information about the specified host).
notes_url:	This variable is used to define an optional URL that can be used to provide more information about the host. If you specify an URL, you will see a link that says “Extra Host Notes” in the extended information CGI (when you are viewing information about the specified host). Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/). This can be very useful if you want to make detailed information on the host, emergency contact methods, etc. available to other support staff.
action_url:	This directive is used to define an optional URL that can be used to provide more actions to be performed on the host. If you specify an URL, you will see a link that says “Extra Host Actions” in the extended information CGI (when you are viewing information about the specified host). Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/).
icon_image:	This variable is used to define the name of a GIF, PNG, or JPG image that should be associated with this host. This image will be displayed in the status and extended information CGIs. The image will look best if it is 40×40 pixels in size. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
icon_image_alt:	This variable is used to define an optional string that is used in the ALT tag of the image specified by the <icon_image> argument. The ALT tag is used in the status, extended information and statusmap CGIs.
vrml_image:	This variable is used to define the name of a GIF, PNG, or JPG image that should be associated with this host. This image will be used as the texture map for the specified host in the statuswrl CGI. Unlike the image you use for the <icon_image> variable, this one should probably not have any transparency. If it does, the host object will look a bit wierd. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
statusmap_image:	This variable is used to define the name of an image that should be associated with this host in the statusmap CGI. You can specify a JPEG, PNG, and GIF image if you want, although I would strongly suggest using a GD2 format image, as other image formats will result in a lot of wasted CPU time when the statusmap image is generated. GD2 images can be created from PNG images by using the pngtogd2 utility supplied with Thomas Boutell’s gd library. The GD2 images should be created in uncompressed format in order to minimize CPU load when the statusmap CGI is generating the network map image. The image will look best if it is 40×40 pixels in size. You can leave these option blank if you are not using the statusmap CGI. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
2d_coords:	This variable is used to define coordinates to use when drawing the host in the statusmap CGI. Coordinates should be given in positive integers, as they correspond to physical pixels in the generated image. The origin for drawing (0,0) is in the upper left hand corner of the image and extends in the positive x direction (to the right) along the top of the image and in the positive y direction (down) along the left hand side of the image. For reference, the size of the icons drawn is usually about 40×40 pixels (text takes a little extra space). The coordinates you specify here are for the upper left hand corner of the host icon that is drawn. Note: Don’t worry about what the maximum x and y coordinates that you can use are. The CGI will automatically calculate the maximum dimensions of the image it creates based on the largest x and y coordinates you specify.
3d_coords:	This variable is used to define coordinates to use when drawing the host in the statuswrl CGI. Coordinates can be positive or negative real numbers. The origin for drawing is (0.0,0.0,0.0). For reference, the size of the host cubes drawn is 0.5 units on each side (text takes a little more space). The coordinates you specify here are used as the center of the host cube.

Extended Service Information Definition

Description:

Extended service information entries are basically used to make the output from the status and extinfo CGIs look pretty. They have no effect on monitoring and are completely optional.

Tip: As of Nagios 3.x, all directives contained in extended service information definitions are also available in service definitions. Thus, you can choose to define the directives below in your service definitions if it makes your configuration simpler. Separate extended service information definitions will continue to be supported for backward compatability.

Definition Format:

Note: Variables in red are required, while those in black are optional. However, you need to supply at least one optional variable in each definition for it to be of much use.

define serviceextinfo{
	host_name	host_name
	service_description	service_description
	notes	note_string
	notes_url	url
	action_url	url
	icon_image	image_file
	icon_image_alt	alt_string
	}

Example Definition:

define serviceextinfo{
	host_name		linux2
	service_description	Log Anomalies
	notes			Security-related log anomalies on secondary Linux server
	notes_url		http://webserver.localhost.localdomain/serviceinfo.pl?host=linux2&service=Log+Anomalies
	icon_image		security.png 
	icon_image_alt		Security-Related Alerts
	}

Variable Descriptions:

host_name:	This directive is used to identify the short name of the host that the service is associated with.
service_description:	This directive is description of the service which the data is associated with.
notes:	This directive is used to define an optional string of notes pertaining to the service. If you specify a note here, you will see the it in the extended information CGI (when you are viewing information about the specified service).
notes_url:	This directive is used to define an optional URL that can be used to provide more information about the service. If you specify an URL, you will see a link that says “Extra Service Notes” in the extended information CGI (when you are viewing information about the specified service). Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/). This can be very useful if you want to make detailed information on the service, emergency contact methods, etc. available to other support staff.
action_url:	This directive is used to define an optional URL that can be used to provide more actions to be performed on the service. If you specify an URL, you will see a link that says “Extra Service Actions” in the extended information CGI (when you are viewing information about the specified service). Any valid URL can be used. If you plan on using relative paths, the base path will the the same as what is used to access the CGIs (i.e. /cgi-bin/nagios/).
icon_image:	This variable is used to define the name of a GIF, PNG, or JPG image that should be associated with this host. This image will be displayed in the status and extended information CGIs. The image will look best if it is 40×40 pixels in size. Images for hosts are assumed to be in the logos/ subdirectory in your HTML images directory (i.e. /usr/local/nagios/share/images/logos).
icon_image_alt:	This variable is used to define an optional string that is used in the ALT tag of the image specified by the <icon_image> argument. The ALT tag is used in the status, extended information and statusmap CGIs.