icinga2/doc/8-differences-between-icinga-1x-and-2.md

Differences between Icinga 1.x and 2

Configuration Format

Icinga 1.x supports two configuration formats: key-value-based settings in the icinga.cfg configuration file and object-based in included files (cfg_dir, cfg_file). The path to the icinga.cfg configuration file must be passed to the Icinga daemon at startup.

enable_notifications=1

define service {
   notifications_enabled    0
}

Icinga 2 supports objects and (global) variables, but does not make a difference if it's the main configuration file, or any included file.

set IcingaEnableNotifications = 1,

object Service "test" {
    enable_notifications = 0,
}

Sample Configuration and ITL

While Icinga 1.x ships sample configuration and templates spread in various object files Icinga 2 moves all templates into the Icinga Template Library (ITL) and includes that in the sample configuration.

The ITL will be updated on every release and should not be edited by the user.

Note

Sample configuration files are located in the conf.d/ directory which is included in icinga2.conf by default.

Include Files and Directories

In Icinga 1.x the icinga.cfg file contains cfg_file and cfg_dir directives. The cfg_dir directive recursively includes all files with a .cfg suffix in the given directory. Only absolute paths may be used. The cfg_file and cfg_dir directives can include the same file twice which leads to configuration errors in Icinga 1.x.

cfg_file=/etc/icinga/objects/commands.cfg
cfg_dir=/etc/icinga/objects

Icinga 2 supports wildcard includes and relative paths, e.g. for including conf.d/*.conf in the same directory. A global search path for includes is available for advanced features like the Icinga Template Library (ITL). The file suffix does not matter as long as it matches the (wildcard) include expression.

include "conf.d/*.conf"
include <itl/itl.conf>

Best Practice

By convention the .conf suffix is used for Icinga 2 configuration files.

Resource File and Global Macros

Global macros such as for the plugin directory, usernames and passwords can be set in the resource.cfg configuration file in Icinga 1.x. By convention the USER1 macro is used to define the directory for the plugins.

Icinga 2 uses a global IcingaMacros variable which is set in the conf.d/macros.conf file:

/**
 * Global macros
*/
set IcingaMacros = {
  plugindir = "/usr/lib/nagios/plugins"
}

Comments

In Icinga 1.x comments are made using a leading hash (#) or a semi-colon (;) for inline comments.

In Icinga 2 comments can either be encapsulated by /* and */ (allowing for multi-line comments) or starting with two slashes (//).

Object names

Object names must not contain a colon (:). Use the display_name attribute to specify user-friendly names which should be shown in UIs (supported by Icinga 1.x Classic UI and Web).

Object names are not specified using attributes (e.g. service_description for services) like in Icinga 1.x but directly after their type definition.

define service {
    host_name  localhost
    service_description  ping4
}

object Service "localhost-ping4" { }

Templates

In Icinga 1.x templates are identified using the register 0 setting. Icinga 2 uses the template identifier:

template Service "ping4-template" { }

Icinga 1.x objects inherit from templates using the use attribute. Icinga 2 uses the keyword inherits after the object name and requires a comma-separated list with template names in double quotes.

define service {
    service_description testservice
    use                 tmpl1,tmpl2,tmpl3
}

object Service "testservice" inherits "tmpl1", "tmpl2", "tmpl3" {
}

Object attributes

Icinga 1.x separates attribute and value with whitespaces/tabs. Icinga 2 requires an equal sign (=) between them.

define service {
    check_interval  5
}

object Service "test" {
    check_interval = 5m,
}

Note

Please note that the default time value is seconds, if no duration literal is given. check_interval = 5 behaves the same as check_interval = 5s.

All strings require double quotes in Icinga 2. Therefore a double-quote must be escaped with a backslash (e.g. in command line). If an attribute identifier starts with a number, it must be encapsulated with double quotes as well.

Unlike in Icinga 1.x all attributes within the current object must be terminated with a comma (,).

Alias vs. Display Name

In Icinga 1.x a host can have an alias and a display_name attribute used for a more descriptive name. A service only can have a display_name attribute. The alias is used for group, timeperiod, etc. objects too. Icinga 2 only supports the display_name attribute which is also taken into account by Icinga 1.x Classic UI and Web.

Custom Attributes

Action Url, Notes Url, Notes

Icinga 1.x objects support configuration attributes not required as runtime values but for external ressources such as Icinga 1.x Classic UI or Web. The notes, notes_url, action_url, icon_image, icon_image_alt attributes for host and service objects, additionally statusmap_image and 2d_coords for the host's representation in status maps.

These attributes can be set using the custom dictionary in Icinga 2 Host or Service objects:

custom = {
    notes = "Icinga 2 is the best!",
    notes_url = "http://docs.icinga.org",
    action_url = "http://dev.icinga.org",
    icon_image = "../../images/logos/Stats2.png",
    icon_image_alt = "icinga2 alt icon text",
    "2d_coords" = "1,2",
    statusmap_image = "../../images/logos/icinga.gif",
}

External interfaces will recognize and display these attributes accordingly.

Custom Variables

Icinga 1.x custom variable attributes must be prefixed using an underscore (_). In Icinga 2 these attributes must be added to the customdictionary.

custom = {
    DN = "cn=icinga2-dev-host,ou=icinga,ou=main,ou=IcingaConfig,ou=LConf,dc=icinga,dc=org",
    CV = "my custom cmdb description",
}

Note

If you are planning to access custom variables as runtime macros you should add them to the macros dictionary instead!

Host Service Relation

In Icinga 1.x a service object is associated with a host by defining the host_name attribute in the service definition. Alternate methods refer to hostgroup_name or behavior changing regular expression. It's not possible to define a service definition within a host definition.

The preferred way of associating hosts with services in Icinga 2 are services defined inline to the host object (or template) definition. Icinga 2 will implicitely create a new service object on configuration activation. These inline service definitions can reference service templates. Linking a service to a host is still possible with the 'host' attribute in a service object in Icinga 2.

Users

Contacts have been renamed to Users (same for groups). A user does not only provide attributes and macros used for notifications, but is also used for authorization checks.

In Icinga 2 notification commands are not directly associated with users. Instead the notification command is specified using Notification objects.

The StatusDataWriter, IdoMySqlConnection and LivestatusListener types will provide the contact and contactgroups attributes for services for compatibility reasons. These values are calculated from all services, their notifications, and their users.

Macros

Various object attributes and runtime variables can be accessed as macros in commands in Icinga 1.x - Icinga 2 supports all required macros.

Note

Due to the contactobjects renamed to user objects the associated macros have changed. Furthermore an alias is now reflected as display_name. The Icinga 1.x notation is still supported for compatibility reasons.

Icinga 1.x Name	Icinga 2 Name
CONTACTNAME	USERNAME
CONTACTALIAS	USERDISPLAYNAME
CONTACTEMAIL	USEREMAIL
CONTACTPAGER	USERPAGER

Command Macros

If you have previously used Icinga 1.x you may already be familiar with user and argument macros (e.g., USER1 or ARG1). Unlike in Icinga 1.x macros may have arbitrary names and arguments are no longer specified in the check_command setting.

In Icinga 1.x argument macros are specified in the check_command attribute and are separated from the command name using an exclamation mark (!).

define command {
    command_name  ping4
    command_line  $USER1$/check_ping -H $HOSTADDRESS$ -w $ARG1$ -c $ARG2$ -p 5
}

define service {
    use                     local-service
    host_name               localhost
    service_description     PING
    check_command           ping4!100.0,20%!500.0,60%
}

With the freely definable macros in Icinga 2 it looks like this:

object CheckCommand "ping4" {
    command = "$plugindir$/check_ping -H $HOSTADDRESS$ -w $wrta$,$wpl%$ -c $crta$,$cpl%$",
}

object Service "PING" {
    check_command = "ping4",
    macros = {
        wrta = 100,
        wpl = 20,
        crta = 500,
        cpl = 60
    }
}

Note

Tip: The above example uses the global plugindir macro instead of the Icinga 1.x USER1 macro. It also replaces the Icinga 1.x notation with ARGn with freely definable macros.

Environment Macros

The global configuration setting enable_environment_macros does not exist in Icinga 2.

Macros exported into the environment must be set using the export_macros attribute in command objects.

Checks

Host Check

Unlike in Icinga 1.x hosts are not checkable objects in Icinga 2. Instead hosts inherit their state from the service that is specified using the check attribute.

Check Output

Icinga 2 does not make a difference between output (first line) and long_output (remaining lines) like in Icinga 1.x. Performance Data is provided separately.

The StatusDataWriter, IdoMysqlConnection and LivestatusListener types split the raw output into output (first line) and long_output (remaining lines) for compatibility reasons.

Initial State

Icinga 1.x uses the max_service_check_spread setting to specify a timerange where the initial state checks must have happened. Icinga 2 will use the retry_interval setting instead and check_interval divided by 5 if retry_interval is not defined.

Performance Data

There is no host performance data generated in Icinga 2 because there are no real host checks. Therefore the PerfDataWriter will only write service performance data files.

Commands

Unlike in Icinga 1.x there are 3 different command types in Icinga 2: CheckCommand, NotificationCommand and EventCommand`.

For example in Icinga 1.x it is possible to accidently use a notification command as an event handler which might cause problems depending on which macros are used in the notification command.

In Icinga 2 these command types are separated and will generate an error on configuration validation if used in the wrong context.

While Icinga 2 still supports the complete command line in command objects, it's also possible to encapsulate all arguments into double quotes and passing them as array to the command_line attribute i.e. for better readability.

It's also possible to define default macros for the command itself which can be overridden by a service macro.

Groups

In Icinga 2 hosts, services and users are added to groups using the groups attribute in the object. The old way of listing all group members in the group's members attribute is not supported.

The preferred way of assigning objects to groups is by using a template:

template Host "dev-host" {
  groups += [ "dev-hosts" ],

  services["http"] = {
    check_command = [ "http-ip" ]
  }
}

object Host "web-dev" inherits "dev-host" { }

Host groups in Icinga 2 cannot be used to associate services with all members of that group. The example above shows how to use templates to accomplish the same effect.

Notifications

Notifications are a new object type in Icinga 2. Imagine the following notification configuration problem in Icinga 1.x:

• Service A should notify contact X via SMS
• Service B should notify contact X via Mail
• Service C should notify contact Y via Mail and SMS
• Contact X and Y should also be used for authorization (e.g. in Classic UI)

The only way achieving a semi-clean solution is to

• Create contact X-sms, set service_notification_command for sms, assign contact to service A
• Create contact X-mail, set service_notification_command for mail, assign contact to service B
• Create contact Y, set service_notification_command for sms and mail, assign contact to service C
• Create contact X without notification commands, assign to service A and B

Basically you are required to create duplicated contacts for either each notification method or used for authorization only.

Icinga 2 attempts to solve that problem in this way

• Create user X, set SMS and Mail attributes, used for authorization
• Create user Y, set SMS and Mail attributes, used for authorization
• Create notification A-SMS, set notification_command for sms, add user X, assign notification A-SMS to service A
• Create notification B-Mail, set notification_command for mail, add user X, assign notification Mail to service B
• Create notification C-SMS, set notification_command for sms, add user Y, assign notification C-SMS to service C
• Create notification C-Mail, set notification_command for mail, add user Y, assign notification C-Mail to service C

Note

Notification objects are not required to be service-agnostic. They may use global notification templates and can be added to a service wherever needed.

Previously in Icinga 1.x it looked like this:

service -> (contact, contactgroup) -> notification command

In Icinga 2 it will look like this:

Service -> Notification -> NotificationCommand
                        -> User, UserGroup

Escalations

Escalations in Icinga 1.x require a separated object matching on existing objects. Escalations happen between a defined start and end time which is calculated from the notification_interval:

start = notification start + (notification_interval * first_notification)
end = notification start + (notification_interval * last_notification)

In theory first_notification and last_notification can be set to readable numbers. In practice users are manipulating those attributes in combination with notification_interval in order to get a start and end time.

In Icinga 2 the notification object can be used as notification escalation if the start and end times are defined within the 'times' attribute using duration literals (e.g. 30m).

The Icinga 2 escalation does not replace the current running notification. In Icinga 1.x it's required to copy the contacts from the service notification to the escalation to garantuee the normal notifications once an escalation happens. That's not necessary with Icinga 2 only requiring an additional notification object for the escalation itself.

Notification Options

Unlike Icinga 1.x with the 'notification_options' attribute with comma-separated state and type filters, Icinga 2 uses two configuration attributes for that. All state and type filter use long names or'd with a pipe together

notification_options w,u,c,r,f,s

notification_state_filter = (StateFilterWarning | StateFilterUnknown | StateFilterCritical),
notification_type_filter = (NotificationProblem | NotificationRecovery | NotificationFlappingStart | NotificationFlappingEnd | NotificationDowntimeStart | NotificationDowntimeEnd | NotificationDowntimeRemoved)

Note

Please note that NotificationProblem as type is required for all problem notifications.

Icinga 2 adds more fine-grained type filters for acknowledgements, downtime and flapping type (start, end, ...).

Note

Notification state and type filters are only valid configuration attributes for Notification and User objects.

Dependencies and Parents

In Icinga 1.x it's possible to define host parents to determine network reachability and keep a host's state unreachable rather than down. Furthermore there are host and service dependencies preventing unnecessary checks and notifications. A host must not depend on a service, and vice versa. All dependencies are configured as separate objects and cannot be set directly on the host or service object.

Icinga 2 adds host and service dependencies as attribute directly onto the host or service object or template. A service can now depend on a host, and vice versa. A service has an implicit dependeny (parent) to its host. A host to host dependency acts implicit as host parent relation.

The StatusDataWriter, IdoMysqlConnection and LivestatusListener types support the Icinga 1.x schema with dependencies and parent attributes for compatibility reasons.

Flapping

The Icinga 1.x flapping detection uses the last 21 states of a service. This value is hardcoded and cannot be changed. The algorithm on determining a flapping state is as follows:

flapping value = (number of actual state changes / number of possible state changes)

The flapping value is then compared to the low and high flapping thresholds.

The algorithm used in Icinga 2 does not store the past states but calculcates the flapping threshold from a single value based on counters and half-life values. Icinga 2 compares the value with a single flapping threshold configuration attribute.

Check Result Freshness

Freshness of check results must be explicitely enabled in Icinga 1.x. The attribute freshness_treshold defines the threshold in seconds. Once the threshold is triggered, an active freshness check is executed defined by the check_command attribute. Both check methods (active and passive) use the same freshness check method.

In Icinga 2 active check freshness is determined by the check_interval attribute and no incoming check results in that period of time (last check + check interval). Passive check freshness is calculated from the check_interval attribute if set. There is no extra freshness_threshold attribute in Icinga 2. If the freshness checks are invalid, a new service check is forced.

State Retention

Icinga 1.x uses the retention.dat file to save its state in order to be able to reload it after a restart. In Icinga 2 this file is called icinga2.state.

The format objects are stored in is not compatible with Icinga 1.x.

Logging

Icinga 1.x supports syslog facilities and writes its own icinga.log log file and archives. These logs are used in Icinga 1.x Classic UI to generate historical reports.

Icinga 2 compat library provides the CompatLogger object which writes the icinga.log and archive in Icinga 1.x format in order to stay compatible with Classic UI and other addons. The native Icinga 2 logging facilities are split into three configuration objects: SyslogLogger, FileLogger, StreamLogger. Each of them got their own severity and target configuration.

Broker Modules and Features

Icinga 1.x broker modules are incompatible with Icinga 2.

In order to provide compatibility with Icinga 1.x the functionality of several popular broker modules was implemented for Icinga 2:

• IDOUtils
• Livestatus
• Cluster (allows for high availability and load balancing)

In Icinga 1.x broker modules may only be loaded once which means it is not easily possible to have one Icinga instance write to multiple IDO databases. Due to the way objects work in Icinga 2 it is possible to set up multiple IDO database instances.

Distributed Monitoring

Icinga 1.x uses the native "obsess over host/service" method which requires the NSCA addon passing the slave's checkresults passively onto the master's external command pipe. While this method may be used for check load distribution, it does not provide any configuration distribution out-of-the-box. Furthermore comments, downtimes and other stateful runtime data is not synced between the master and slave nodes. There are addons available solving the check and configuration distribution problems Icinga 1.x distributed monitoring currently suffers from.

Icinga 2 implements a new built-in distributed monitoring architecture, including config and check distribution, IPv4/IPv6 support, SSL certificates and domain support for DMZ. High Availability and load balancing are also part of the Icinga 2 Cluster setup.