1 # Advanced Topics <a id="advanced-topics"></a>
3 This chapter covers a number of advanced topics. If you're new to Icinga, you
4 can safely skip over things you're not interested in.
6 ## Downtimes <a id="downtimes"></a>
8 Downtimes can be scheduled for planned server maintenance or
9 any other targeted service outage you are aware of in advance.
11 Downtimes suppress notifications and can trigger other
12 downtimes too. If the downtime was set by accident, or the duration
13 exceeds the maintenance windows, you can manually cancel the downtime.
15 ### Scheduling a downtime <a id="scheduling-downtime"></a>
17 The most convenient way to schedule planned downtimes is to create
18 them in Icinga Web 2 inside the host/service detail view. Select
19 multiple hosts/services from the listing with the shift key to
20 schedule multiple downtimes.
22 ![Downtime in Icinga Web 2](images/advanced-topics/icingaweb2_downtime_handled.png)
24 In addition to that you can schedule a downtime by using the Icinga 2 API action
25 [schedule-downtime](12-icinga2-api.md#icinga2-api-actions-schedule-downtime).
26 This is especially useful to schedule a downtime on-demand inside a (remote) backup
27 script, or create maintenance downtimes from a cron job for specific dates and intervals.
29 Multiple downtimes for a single object may overlap. This is useful
30 when you want to extend your maintenance window taking longer than expected.
31 If there are multiple downtimes triggered for one object, the overall downtime depth
32 will be greater than `1`.
34 If the downtime was scheduled after the problem changed to a critical hard
35 state triggering a problem notification, and the service recovers during
36 the downtime window, the recovery notification won't be suppressed.
38 Planned downtimes are also taken into account for SLA reporting
39 tools calculating the SLAs based on the state and downtime history.
41 ### Fixed and Flexible Downtimes <a id="fixed-flexible-downtimes"></a>
43 A `fixed` downtime will be activated at the defined start time, and
44 removed at the end time. During this time window the service state
45 will change to `NOT-OK` and then actually trigger the downtime.
46 Notifications are suppressed and the downtime depth is incremented.
48 Common scenarios are a planned distribution upgrade on your linux
49 servers, or database updates in your warehouse. The customer knows
50 about a fixed downtime window between 23:00 and 24:00. After 24:00
51 all problems should be alerted again. Solution is simple -
52 schedule a `fixed` downtime starting at 23:00 and ending at 24:00.
54 Unlike a `fixed` downtime, a `flexible` downtime will be triggered
55 by the state change in the time span defined by start and end time,
56 and then last for the specified duration in minutes.
58 Imagine the following scenario: Your service is frequently polled
59 by users trying to grab free deleted domains for immediate registration.
60 Between 07:30 and 08:00 the impact will hit for 15 minutes and generate
61 a network outage visible to the monitoring. The service is still alive,
62 but answering too slow to Icinga 2 service checks.
63 For that reason, you may want to schedule a downtime between 07:30 and
64 08:00 with a duration of 15 minutes. The downtime will then last from
65 its trigger time until the duration is over. After that, the downtime
66 is removed (may happen before or after the actual end time!).
68 #### Fixed Downtime <a id="fixed-downtime"></a>
70 If the host/service changes into a NOT-OK state between the start and
71 end time window, the downtime will be marked as `in effect` and
72 increases the downtime depth counter.
80 #### Flexible Downtime <a id="flexible-downtime"></a>
82 A flexible downtime defines a time window where the downtime may be
83 triggered from a host/service NOT-OK state change. It will then last
84 until the specified time duration is reached. That way it can happen
85 that the downtime end time is already gone, but the downtime ends
86 at `trigger time + duration`.
91 start | end actual end time
92 |--------------duration--------|
97 ### Triggered Downtimes <a id="triggered-downtimes"></a>
99 This is optional when scheduling a downtime. If there is already a downtime
100 scheduled for a future maintenance, the current downtime can be triggered by
101 that downtime. This renders useful if you have scheduled a host downtime and
102 are now scheduling a child host's downtime getting triggered by the parent
103 downtime on `NOT-OK` state change.
105 ### Recurring Downtimes <a id="recurring-downtimes"></a>
107 [ScheduledDowntime objects](09-object-types.md#objecttype-scheduleddowntime) can be used to set up
108 recurring downtimes for services.
113 apply ScheduledDowntime "backup-downtime" to Service {
114 author = "icingaadmin"
115 comment = "Scheduled downtime for backup"
118 monday = "02:00-03:00"
119 tuesday = "02:00-03:00"
120 wednesday = "02:00-03:00"
121 thursday = "02:00-03:00"
122 friday = "02:00-03:00"
123 saturday = "02:00-03:00"
124 sunday = "02:00-03:00"
127 assign where "backup" in service.groups
131 Icinga 2 attempts to find the next possible segment from a ScheduledDowntime object's
132 `ranges` attribute, and wont create multiple downtimes in the future. In case you need
133 all these downtimes planned and visible for the next days, weeks or months, schedule them
134 manually via the [REST API](12-icinga2-api.md#icinga2-api-actions-schedule-downtime) using
135 a script or cron job.
139 > If ScheduledDowntime objects are synced in a distributed high-availability setup,
140 > both will create the next possible downtime on their own. These runtime generated
141 > downtimes are synced among both zone instances, and you may see sort-of duplicate downtimes
145 ## Comments <a id="comments-intro"></a>
147 Comments can be added at runtime and are persistent over restarts. You can
148 add useful information for others on repeating incidents (for example
149 "last time syslog at 100% cpu on 17.10.2013 due to stale nfs mount") which
150 is primarily accessible using web interfaces.
152 You can add a comment either by using the Icinga 2 API action
153 [add-comment](12-icinga2-api.md#icinga2-api-actions-add-comment) or
154 by sending an [external command](14-features.md#external-commands).
156 ## Acknowledgements <a id="acknowledgements"></a>
158 If a problem persists and notifications have been sent, you can
159 acknowledge the problem. That way other users will get
160 a notification that you're aware of the issue and probably are
161 already working on a fix.
163 Note: Acknowledgements also add a new [comment](08-advanced-topics.md#comments-intro)
164 which contains the author and text fields.
166 You can send an acknowledgement either by using the Icinga 2 API action
167 [acknowledge-problem](12-icinga2-api.md#icinga2-api-actions-acknowledge-problem) or
168 by sending an [external command](14-features.md#external-commands).
171 ### Sticky Acknowledgements <a id="sticky-acknowledgements"></a>
173 The acknowledgement is removed if a state change occurs or if the host/service
174 recovers (OK/Up state).
176 If you acknowledge a problem once you've received a `Critical` notification,
177 the acknowledgement will be removed if there is a state transition to `Warning`.
179 OK -> WARNING -> CRITICAL -> WARNING -> OK
182 If you prefer to keep the acknowledgement until the problem is resolved (`OK`
183 recovery) you need to enable the `sticky` parameter.
186 ### Expiring Acknowledgements <a id="expiring-acknowledgements"></a>
188 Once a problem is acknowledged it may disappear from your `handled problems`
189 dashboard and no-one ever looks at it again since it will suppress
192 This `fire-and-forget` action is quite common. If you're sure that a
193 current problem should be resolved in the future at a defined time,
194 you can define an expiration time when acknowledging the problem.
196 Icinga 2 will clear the acknowledgement when expired and start to
197 re-notify, if the problem persists.
200 ## Time Periods <a id="timeperiods"></a>
202 [Time Periods](09-object-types.md#objecttype-timeperiod) define
203 time ranges in Icinga where event actions are triggered, for
204 example whether a service check is executed or not within
205 the `check_period` attribute. Or a notification should be sent to
206 users or not, filtered by the `period` and `notification_period`
207 configuration attributes for `Notification` and `User` objects.
209 The `TimePeriod` attribute `ranges` may contain multiple directives,
210 including weekdays, days of the month, and calendar dates.
211 These types may overlap/override other types in your ranges dictionary.
213 The descending order of precedence is as follows:
215 * Calendar date (2008-01-01)
216 * Specific month date (January 1st)
217 * Generic month date (Day 15)
218 * Offset weekday of specific month (2nd Tuesday in December)
219 * Offset weekday (3rd Monday)
220 * Normal weekday (Tuesday)
222 If you don't set any `check_period` or `notification_period` attribute
223 on your configuration objects, Icinga 2 assumes `24x7` as time period
227 object TimePeriod "24x7" {
228 display_name = "Icinga 2 24x7 TimePeriod"
230 "monday" = "00:00-24:00"
231 "tuesday" = "00:00-24:00"
232 "wednesday" = "00:00-24:00"
233 "thursday" = "00:00-24:00"
234 "friday" = "00:00-24:00"
235 "saturday" = "00:00-24:00"
236 "sunday" = "00:00-24:00"
241 If your operation staff should only be notified during workhours,
242 create a new timeperiod named `workhours` defining a work day from
246 object TimePeriod "workhours" {
247 display_name = "Icinga 2 8x5 TimePeriod"
249 "monday" = "09:00-17:00"
250 "tuesday" = "09:00-17:00"
251 "wednesday" = "09:00-17:00"
252 "thursday" = "09:00-17:00"
253 "friday" = "09:00-17:00"
258 If you want to specify a notification period across midnight,
259 you can define it the following way:
262 object Timeperiod "across-midnight" {
263 display_name = "Nightly Notification"
265 "saturday" = "22:00-24:00"
266 "sunday" = "00:00-03:00"
271 Below you can see another example for configuring timeperiods across several
272 days, weeks or months. This can be useful when taking components offline
273 for a distinct period of time.
276 object Timeperiod "standby" {
277 display_name = "Standby"
279 "2016-09-30 - 2016-10-30" = "00:00-24:00"
284 Please note that the spaces before and after the dash are mandatory.
286 Once your time period is configured you can Use the `period` attribute
287 to assign time periods to `Notification` and `Dependency` objects:
290 apply Notification "mail-icingaadmin" to Service {
291 import "mail-service-notification"
292 user_groups = host.vars.notification.mail.groups
293 users = host.vars.notification.mail.users
297 assign where host.vars.notification.mail
301 ### Time Periods Inclusion and Exclusion <a id="timeperiods-includes-excludes"></a>
303 Sometimes it is necessary to exclude certain time ranges from
304 your default time period definitions, for example, if you don't
305 want to send out any notification during the holiday season,
306 or if you only want to allow small time windows for executed checks.
308 The [TimePeriod object](09-object-types.md#objecttype-timeperiod)
309 provides the `includes` and `excludes` attributes to solve this issue.
310 `prefer_includes` defines whether included or excluded time periods are
313 The following example defines a time period called `holidays` where
314 notifications should be suppressed:
317 object TimePeriod "holidays" {
319 "january 1" = "00:00-24:00" //new year's day
320 "july 4" = "00:00-24:00" //independence day
321 "december 25" = "00:00-24:00" //christmas
322 "december 31" = "18:00-24:00" //new year's eve (6pm+)
323 "2017-04-16" = "00:00-24:00" //easter 2017
324 "monday -1 may" = "00:00-24:00" //memorial day (last monday in may)
325 "monday 1 september" = "00:00-24:00" //labor day (1st monday in september)
326 "thursday 4 november" = "00:00-24:00" //thanksgiving (4th thursday in november)
331 In addition to that the time period `weekends` defines an additional
332 time window which should be excluded from notifications:
335 object TimePeriod "weekends-excluded" {
337 "saturday" = "00:00-09:00,18:00-24:00"
338 "sunday" = "00:00-09:00,18:00-24:00"
343 The time period `prod-notification` defines the default time ranges
344 and adds the excluded time period names as an array.
347 object TimePeriod "prod-notification" {
348 excludes = [ "holidays", "weekends-excluded" ]
351 "monday" = "00:00-24:00"
352 "tuesday" = "00:00-24:00"
353 "wednesday" = "00:00-24:00"
354 "thursday" = "00:00-24:00"
355 "friday" = "00:00-24:00"
356 "saturday" = "00:00-24:00"
357 "sunday" = "00:00-24:00"
362 ## External Check Results <a id="external-check-results"></a>
364 Hosts or services which do not actively execute a check plugin to receive
365 the state and output are called "passive checks" or "external check results".
366 In this scenario an external client or script is sending in check results.
368 You can feed check results into Icinga 2 with the following transport methods:
370 * [process-check-result action](12-icinga2-api.md#icinga2-api-actions-process-check-result) available with the [REST API](12-icinga2-api.md#icinga2-api) (remote and local)
371 * External command sent via command pipe (local only)
373 Each time a new check result is received, the next expected check time
374 is updated. This means that if there are no check result received from
375 the external source, Icinga 2 will execute [freshness checks](08-advanced-topics.md#check-result-freshness).
379 > The REST API action allows to specify the `check_source` attribute
380 > which helps identifying the external sender. This is also visible
381 > in Icinga Web 2 and the REST API queries.
383 ## Check Result Freshness <a id="check-result-freshness"></a>
385 In Icinga 2 active check freshness is enabled by default. It is determined by the
386 `check_interval` attribute and no incoming check results in that period of time.
388 The threshold is calculated based on the last check execution time for actively executed checks:
390 (last check execution time + check interval) > current time
392 If this host/service receives check results from an [external source](08-advanced-topics.md#external-check-results),
393 the threshold is based on the last time a check result was received:
395 (last check result time + check interval) > current time
399 > The [process-check-result](12-icinga2-api.md#icinga2-api-actions-process-check-result) REST API
400 > action allows to overrule the pre-defined check interval with a specified TTL in Icinga 2 v2.9+.
402 If the freshness checks fail, Icinga 2 will execute the defined check command.
404 Best practice is to define a [dummy](10-icinga-template-library.md#itl-dummy) `check_command` which gets
405 executed when freshness checks fail.
408 apply Service "external-check" {
409 check_command = "dummy"
412 /* Set the state to UNKNOWN (3) if freshness checks fail. */
415 /* Use a runtime function to retrieve the last check time and more details. */
417 var service = get_service(macro("$host.name$"), macro("$service.name$"))
418 var lastCheck = DateTime(service.last_check).to_string()
420 return "No check results received. Last result time: " + lastCheck
423 assign where "external" in host.vars.services
427 References: [get_service](18-library-reference.md#objref-get_service), [macro](18-library-reference.md#scoped-functions-macro), [DateTime](18-library-reference.md#datetime-type).
429 Example output in Icinga Web 2:
431 ![Icinga 2 Freshness Checks](images/advanced-topics/icinga2_external_checks_freshness_icingaweb2.png)
434 ## Check Flapping <a id="check-flapping"></a>
436 Icinga 2 supports optional detection of hosts and services that are "flapping".
438 Flapping occurs when a service or host changes state too frequently, which would result in a storm of problem and
439 recovery notifications. With flapping detection enabled a flapping notification will be sent while other notifications are
440 suppressed until it calms down after receiving the same status from checks a few times. Flapping detection can help detect
441 configuration problems (wrong thresholds), troublesome services or network problems.
443 Flapping detection can be enabled or disabled using the `enable_flapping` attribute.
444 The `flapping_threshold_high` and `flapping_threshold_low` attributes allows to specify the thresholds that control
445 when a [host](09-object-types.md#objecttype-host) or [service](09-object-types.md#objecttype-service) is considered to be flapping.
447 The default thresholds are 30% for high and 25% for low. If the computed flapping value exceeds the high threshold a
448 host or service is considered flapping until it drops below the low flapping threshold.
450 `FlappingStart` and `FlappingEnd` notifications will be sent out accordingly, if configured. See the chapter on
451 [notifications](alert-notifications) for details
453 > Note: There is no distinctions between hard and soft states with flapping. All state changes count and notifications
454 > will be sent out regardless of the objects state.
456 ### How it works <a id="check-flapping-how-it-works"></a>
458 Icinga 2 saves the last 20 state changes for every host and service. See the graphic below:
460 ![Icinga 2 Flapping State Timeline](images/advanced-topics/flapping-state-graph.png)
462 All the states are weighted, with the most recent one being worth the most (1.15) and the 20th the least (0.8). The
463 states in between are fairly distributed. The final flapping value are the weighted state changes divided by the total
466 In the example above, the added states would have a total value of 7.82 (`0.84 + 0.86 + 0.88 + 0.9 + 0.98 + 1.06 + 1.12 + 1.18`).
467 This yields a flapping percentage of 39.1% (`7.82 / 20 * 100`). As the default upper flapping threshold is 30%, it would be
470 If the next seven check results then would not be state changes, the flapping percentage would fall below the lower threshold
471 of 25% and therefore the host or service would recover from flapping.
473 ## Volatile Services and Hosts <a id="volatile-services-hosts"></a>
475 The `volatile` option, if enabled for a host or service, makes it treat every [state change](03-monitoring-basics.md#hard-soft-states)
476 as a `HARD` state change. It is comparable to `max_check_attempts = 1`. With this any `NOT-OK` result will
477 ignore `max_check_attempts` and trigger notifications etc. It will further cause any additional `NOT-OK`
478 result to re-send notifications.
480 It may be reasonable to have a volatile service which stays in a `HARD` state if the service stays in a `NOT-OK`
481 state. That way each service recheck will automatically trigger a notification unless the service is acknowledged or
482 in a scheduled downtime.
484 A common example are security checks where each `NOT-OK` check result should immediately trigger a notification.
486 The default for this option is `false` and should only be enabled when required.
489 ## Monitoring Icinga 2 <a id="monitoring-icinga"></a>
491 Why should you do that? Icinga and its components run like any other
492 service application on your server. There are predictable issues
493 such as "disk space is running low" and your monitoring suffers from just
496 You would also like to ensure that features and backends are running
497 and storing required data. Be it the database backend where Icinga Web 2
498 presents fancy dashboards, forwarded metrics to Graphite or InfluxDB or
499 the entire distributed setup.
501 This list isn't complete but should help with your own setup.
502 Windows client specific checks are highlighted.
504 Type | Description | Plugins and CheckCommands
505 ----------------|-------------------------------|-----------------------------------------------------
506 System | Filesystem | [disk](10-icinga-template-library.md#plugin-check-command-disk), [disk-windows](10-icinga-template-library.md#windows-plugins) (Windows Client)
507 System | Memory, Swap | [mem](10-icinga-template-library.md#plugin-contrib-command-mem), [swap](10-icinga-template-library.md#plugin-check-command-swap), [memory](10-icinga-template-library.md#windows-plugins) (Windows Client)
508 System | Hardware | [hpasm](10-icinga-template-library.md#plugin-contrib-command-hpasm), [ipmi-sensor](10-icinga-template-library.md#plugin-contrib-command-ipmi-sensor)
509 System | Virtualization | [VMware](10-icinga-template-library.md#plugin-contrib-vmware), [esxi_hardware](10-icinga-template-library.md#plugin-contrib-command-esxi-hardware)
510 System | Processes | [procs](10-icinga-template-library.md#plugin-check-command-processes), [service-windows](10-icinga-template-library.md#windows-plugins) (Windows Client)
511 System | System Activity Reports | [check_sar_perf](https://github.com/dnsmichi/icinga-plugins/blob/master/scripts/check_sar_perf.py)
512 System | I/O | [iostat](10-icinga-template-library.md#plugin-contrib-command-iostat)
513 System | Network interfaces | [nwc_health](10-icinga-template-library.md#plugin-contrib-command-nwc_health), [interfaces](10-icinga-template-library.md#plugin-contrib-command-interfaces)
514 System | Users | [users](10-icinga-template-library.md#plugin-check-command-users), [users-windows](10-icinga-template-library.md#windows-plugins) (Windows Client)
515 System | Logs | Forward them to [Elastic Stack](14-features.md#elastic-stack-integration) or [Graylog](14-features.md#graylog-integration) and add your own alerts.
516 System | NTP | [ntp_time](10-icinga-template-library.md#plugin-check-command-ntp-time)
517 System | Updates | [apt](10-icinga-template-library.md#plugin-check-command-apt), [yum](10-icinga-template-library.md#plugin-contrib-command-yum)
518 Icinga | Status & Stats | [icinga](10-icinga-template-library.md#itl-icinga) (more below)
519 Icinga | Cluster & Clients | [health checks](06-distributed-monitoring.md#distributed-monitoring-health-checks)
520 Database | MySQL | [mysql_health](10-icinga-template-library.md#plugin-contrib-command-mysql_health)
521 Database | PostgreSQL | [postgres](10-icinga-template-library.md#plugin-contrib-command-postgres)
522 Database | Housekeeping | Check the database size and growth and analyse metrics to examine trends.
523 Database | DB IDO | [ido](10-icinga-template-library.md#itl-icinga-ido) (more below)
524 Webserver | Apache2, Nginx, etc. | [http](10-icinga-template-library.md#plugin-check-command-http), [apache-status](10-icinga-template-library.md#plugin-contrib-command-apache-status), [nginx_status](10-icinga-template-library.md#plugin-contrib-command-nginx_status)
525 Webserver | Certificates | [http](10-icinga-template-library.md#plugin-check-command-http)
526 Webserver | Authorization | [http](10-icinga-template-library.md#plugin-check-command-http)
527 Notifications | Mail (queue) | [smtp](10-icinga-template-library.md#plugin-check-command-smtp), [mailq](10-icinga-template-library.md#plugin-check-command-mailq)
528 Notifications | SMS (GSM modem) | [check_sms3_status](https://exchange.icinga.com/netways/check_sms3status)
529 Notifications | Messengers, Cloud services | XMPP, Twitter, IRC, Telegram, PagerDuty, VictorOps, etc.
530 Metrics | PNP, RRDTool | [check_pnp_rrds](https://github.com/lingej/pnp4nagios/tree/master/scripts) checks for stale RRD files.
531 Metrics | Graphite | [graphite](10-icinga-template-library.md#plugin-contrib-command-graphite)
532 Metrics | InfluxDB | [check_influxdb](https://exchange.icinga.com/Mikanoshi/InfluxDB+data+monitoring+plugin)
533 Metrics | Elastic Stack | [elasticsearch](10-icinga-template-library.md#plugin-contrib-command-elasticsearch), [Elastic Stack integration](14-features.md#elastic-stack-integration)
534 Metrics | Graylog | [Graylog integration](14-features.md#graylog-integration)
537 The [icinga](10-icinga-template-library.md#itl-icinga) CheckCommand provides metrics for the runtime stats of
538 Icinga 2. You can forward them to your preferred graphing solution.
539 If you require more metrics you can also query the [REST API](12-icinga2-api.md#icinga2-api) and write
540 your own custom check plugin. Or you keep using the built-in [object accessor functions](08-advanced-topics.md#access-object-attributes-at-runtime)
541 to calculate stats in-memory.
543 There is a built-in [ido](10-icinga-template-library.md#itl-icinga-ido) check available for DB IDO MySQL/PostgreSQL
544 which provides additional metrics for the IDO database.
547 apply Service "ido-mysql" {
548 check_command = "ido"
550 vars.ido_type = "IdoMysqlConnection"
551 vars.ido_name = "ido-mysql" //the name defined in /etc/icinga2/features-enabled/ido-mysql.conf
553 assign where match("master*.localdomain", host.name)
557 More specific database queries can be found in the [DB IDO](14-features.md#db-ido) chapter.
559 Distributed setups should include specific [health checks](06-distributed-monitoring.md#distributed-monitoring-health-checks).
560 You might also want to add additional checks for SSL certificate expiration.
563 ## Advanced Configuration Hints <a id="advanced-configuration-hints"></a>
565 ### Advanced Use of Apply Rules <a id="advanced-use-of-apply-rules"></a>
567 [Apply rules](03-monitoring-basics.md#using-apply) can be used to create a rule set which is
568 entirely based on host objects and their attributes.
569 In addition to that [apply for and custom attribute override](03-monitoring-basics.md#using-apply-for)
570 extend the possibilities.
572 The following example defines a dictionary on the host object which contains
573 configuration attributes for multiple web servers. This then used to add three checks:
575 * A `ping4` check using the local IP `address` of the web server.
576 * A `tcp` check querying the TCP port where the HTTP service is running on.
577 * If the `url` key is defined, the third apply for rule will create service objects using the `http` CheckCommand.
578 In addition to that you can optionally define the `ssl` attribute which enables HTTPS checks.
582 object Host "webserver01" {
583 import "generic-host"
584 address = "192.168.56.200"
588 instance["status"] = {
589 address = "192.168.56.201"
593 instance["tomcat"] = {
594 address = "192.168.56.202"
597 instance["icingaweb2"] = {
598 address = "192.168.56.210"
606 Service apply for definitions:
608 apply Service "webserver_ping" for (instance => config in host.vars.webserver.instance) {
609 display_name = "webserver_" + instance
610 check_command = "ping4"
612 vars.ping_address = config.address
614 assign where host.vars.webserver.instance
617 apply Service "webserver_port" for (instance => config in host.vars.webserver.instance) {
618 display_name = "webserver_" + instance + "_" + config.port
619 check_command = "tcp"
621 vars.tcp_address = config.address
622 vars.tcp_port = config.port
624 assign where host.vars.webserver.instance
627 apply Service "webserver_url" for (instance => config in host.vars.webserver.instance) {
628 display_name = "webserver_" + instance + "_" + config.url
629 check_command = "http"
631 vars.http_address = config.address
632 vars.http_port = config.port
633 vars.http_uri = config.url
636 vars.http_ssl = config.ssl
639 assign where config.url != ""
642 The variables defined in the host dictionary are not using the typical custom attribute
643 prefix recommended for CheckCommand parameters. Instead they are re-used for multiple
644 service checks in this example.
645 In addition to defining check parameters this way, you can also enrich the `display_name`
646 attribute with more details. This will be shown in in Icinga Web 2 for example.
648 ### Use Functions in Object Configuration <a id="use-functions-object-config"></a>
650 There is a limited scope where functions can be used as object attributes such as:
652 * As value for [Custom Attributes](03-monitoring-basics.md#custom-attributes-functions)
653 * Returning boolean expressions for [set_if](08-advanced-topics.md#use-functions-command-arguments-setif) inside command arguments
654 * Returning a [command](08-advanced-topics.md#use-functions-command-attribute) array inside command objects
656 The other way around you can create objects dynamically using your own global functions.
660 > Functions called inside command objects share the same global scope as runtime macros.
661 > Therefore you can access host custom attributes like `host.vars.os`, or any other
662 > object attribute from inside the function definition used for [set_if](08-advanced-topics.md#use-functions-command-arguments-setif) or [command](08-advanced-topics.md#use-functions-command-attribute).
664 Tips when implementing functions:
666 * Use [log()](18-library-reference.md#global-functions-log) to dump variables. You can see the output
667 inside the `icinga2.log` file depending in your log severity
668 * Use the `icinga2 console` to test basic functionality (e.g. iterating over a dictionary)
669 * Build them step-by-step. You can always refactor your code later on.
671 #### Register and Use Global Functions <a id="use-functions-global-register"></a>
673 [Functions](17-language-reference.md#functions) can be registered into the global scope. This allows custom functions being available
674 in objects and other functions. Keep in mind that these functions are not marked
675 as side-effect-free and as such are not available via the REST API.
677 Add a new configuration file `functions.conf` and include it into the [icinga2.conf](04-configuring-icinga-2.md#icinga2-conf)
678 configuration file in the very beginning, e.g. after `constants.conf`. You can also manage global
679 functions inside `constants.conf` if you prefer.
681 The following function converts a given state parameter into a returned string value. The important
682 bits for registering it into the global scope are:
684 * `globals.<unique_function_name>` adds a new globals entry.
685 * `function()` specifies that a call to `state_to_string()` executes a function.
686 * Function parameters are defined inside the `function()` definition.
689 globals.state_to_string = function(state) {
692 } else if (state == 1) {
694 } else if (state == 0) {
696 } else if (state == 3) {
699 log(LogWarning, "state_to_string", "Unknown state " + state + " provided.")
704 The else-condition allows for better error handling. This warning will be shown in the Icinga 2
705 log file once the function is called.
709 > If these functions are used in a distributed environment, you must ensure to deploy them
712 In order to test-drive the newly created function, restart Icinga 2 and use the [debug console](11-cli-commands.md#cli-command-console)
713 to connect to the REST API.
716 $ ICINGA2_API_PASSWORD=icinga icinga2 console --connect 'https://root@localhost:5665/'
717 Icinga 2 (version: v2.8.1-373-g4bea6d25c)
718 <1> => globals.state_to_string(1)
720 <2> => state_to_string(2)
724 You can see that this function is now registered into the [global scope](17-language-reference.md#variable-scopes). The function call
725 `state_to_string()` can be used in any object at static config compile time or inside runtime
728 The following service object example uses the service state and converts it to string output.
729 The function definition is not optimized and is enrolled for better readability including a log message.
732 object Service "state-test" {
733 check_command = "dummy"
739 var h = macro("$host.name$")
740 var s = macro("$service.name$")
742 var state = get_service(h, s).state
744 log(LogInformation, "dummy_state", "Host: " + h + " Service: " + s + " State: " + state)
746 return state_to_string(state)
752 #### Use Custom Functions as Attribute <a id="custom-functions-as-attribute"></a>
754 To use custom functions as attributes, the function must be defined in a
755 slightly unexpected way. The following example shows how to assign values
756 depending on group membership. All hosts in the `slow-lan` host group use 300
757 as value for `ping_wrta`, all other hosts use 100.
759 globals.group_specific_value = function(group, group_value, non_group_value) {
760 return function() use (group, group_value, non_group_value) {
761 if (group in host.groups) {
764 return non_group_value
769 apply Service "ping4" {
770 import "generic-service"
771 check_command = "ping4"
773 vars.ping_wrta = group_specific_value("slow-lan", 300, 100)
774 vars.ping_crta = group_specific_value("slow-lan", 500, 200)
779 #### Use Functions in Assign Where Expressions <a id="use-functions-assign-where"></a>
781 If a simple expression for matching a name or checking if an item
782 exists in an array or dictionary does not fit, you should consider
783 writing your own global [functions](17-language-reference.md#functions).
784 You can call them inside `assign where` and `ignore where` expressions
785 for [apply rules](03-monitoring-basics.md#using-apply-expressions) or
786 [group assignments](03-monitoring-basics.md#group-assign-intro) just like
787 any other global functions for example [match](18-library-reference.md#global-functions-match).
789 The following example requires the host `myprinter` being added
790 to the host group `printers-lexmark` but only if the host uses
791 a template matching the name `lexmark*`.
793 template Host "lexmark-printer-host" {
794 vars.printer_type = "Lexmark"
797 object Host "myprinter" {
798 import "generic-host"
799 import "lexmark-printer-host"
801 address = "192.168.1.1"
804 /* register a global function for the assign where call */
805 globals.check_host_templates = function(host, search) {
806 /* iterate over all host templates and check if the search matches */
807 for (tmpl in host.templates) {
808 if (match(search, tmpl)) {
813 /* nothing matched */
817 object HostGroup "printers-lexmark" {
818 display_name = "Lexmark Printers"
819 /* call the global function and pass the arguments */
820 assign where check_host_templates(host, "lexmark*")
824 Take a different more complex example: All hosts with the
825 custom attribute `vars_app` as nested dictionary should be
826 added to the host group `ABAP-app-server`. But only if the
827 `app_type` for all entries is set to `ABAP`.
829 It could read as wildcard match for nested dictionaries:
831 where host.vars.vars_app["*"].app_type == "ABAP"
833 The solution for this problem is to register a global
834 function which checks the `app_type` for all hosts
835 with the `vars_app` dictionary.
837 object Host "appserver01" {
838 check_command = "dummy"
839 vars.vars_app["ABC"] = { app_type = "ABAP" }
841 object Host "appserver02" {
842 check_command = "dummy"
843 vars.vars_app["DEF"] = { app_type = "ABAP" }
846 globals.check_app_type = function(host, type) {
847 /* ensure that other hosts without the custom attribute do not match */
848 if (typeof(host.vars.vars_app) != Dictionary) {
852 /* iterate over the vars_app dictionary */
853 for (key => val in host.vars.vars_app) {
854 /* if the value is a dictionary and if contains the app_type being the requested type */
855 if (typeof(val) == Dictionary && val.app_type == type) {
860 /* nothing matched */
864 object HostGroup "ABAP-app-server" {
865 assign where check_app_type(host, "ABAP")
869 #### Use Functions in Command Arguments set_if <a id="use-functions-command-arguments-setif"></a>
871 The `set_if` attribute inside the command arguments definition in the
872 [CheckCommand object definition](09-object-types.md#objecttype-checkcommand) is primarily used to
873 evaluate whether the command parameter should be set or not.
875 By default you can evaluate runtime macros for their existence. If the result is not an empty
876 string, the command parameter is passed. This becomes fairly complicated when want to evaluate
877 multiple conditions and attributes.
879 The following example was found on the community support channels. The user had defined a host
880 dictionary named `compellent` with the key `disks`. This was then used inside service apply for rules.
882 object Host "dict-host" {
883 check_command = "check_compellent"
884 vars.compellent["disks"] = {
885 file = "/var/lib/check_compellent/san_disks.0.json",
890 The more significant problem was to only add the command parameter `--disk` to the plugin call
891 when the dictionary `compellent` contains the key `disks`, and omit it if not found.
893 By defining `set_if` as [abbreviated lambda function](17-language-reference.md#nullary-lambdas)
894 and evaluating the host custom attribute `compellent` containing the `disks` this problem was
897 object CheckCommand "check_compellent" {
898 command = [ "/usr/bin/check_compellent" ]
902 var host_vars = host.vars
904 var compel = host_vars.compellent
906 compel.contains("disks")
912 This implementation uses the dictionary type method [contains](18-library-reference.md#dictionary-contains)
913 and will fail if `host.vars.compellent` is not of the type `Dictionary`.
914 Therefore you can extend the checks using the [typeof](17-language-reference.md#types) function.
916 You can test the types using the `icinga2 console`:
919 Icinga (version: v2.3.0-193-g3eb55ad)
920 <1> => srv_vars.compellent["check_a"] = { file="outfile_a.json", checks = [ "disks", "fans" ] }
922 <2> => srv_vars.compellent["check_b"] = { file="outfile_b.json", checks = [ "power", "voltages" ] }
924 <3> => typeof(srv_vars.compellent)
928 The more programmatic approach for `set_if` could look like this:
932 var srv_vars = service.vars
933 if(len(srv_vars) > 0) {
934 if (typeof(srv_vars.compellent) == Dictionary) {
935 return srv_vars.compellent.contains("disks")
937 log(LogInformationen, "checkcommand set_if", "custom attribute compellent_checks is not a dictionary, ignoring it.")
941 log(LogWarning, "checkcommand set_if", "empty custom attributes")
948 #### Use Functions as Command Attribute <a id="use-functions-command-attribute"></a>
950 This comes in handy for [NotificationCommands](09-object-types.md#objecttype-notificationcommand)
951 or [EventCommands](09-object-types.md#objecttype-eventcommand) which does not require
952 a returned checkresult including state/output.
954 The following example was taken from the community support channels. The requirement was to
955 specify a custom attribute inside the notification apply rule and decide which notification
956 script to call based on that.
958 object User "short-dummy" {
961 object UserGroup "short-dummy-group" {
962 assign where user.name == "short-dummy"
965 apply Notification "mail-admins-short" to Host {
966 import "mail-host-notification"
967 command = "mail-host-notification-test"
968 user_groups = [ "short-dummy-group" ]
970 assign where host.vars.notification.mail
973 The solution is fairly simple: The `command` attribute is implemented as function returning
974 an array required by the caller Icinga 2.
975 The local variable `mailscript` sets the default value for the notification scrip location.
976 If the notification custom attribute `short` is set, it will override the local variable `mailscript`
978 The `mailscript` variable is then used to compute the final notification command array being
981 You can omit the `log()` calls, they only help debugging.
983 object NotificationCommand "mail-host-notification-test" {
985 log("command as function")
986 var mailscript = "mail-host-notification-long.sh"
987 if (notification.vars.short) {
988 mailscript = "mail-host-notification-short.sh"
990 log("Running command")
993 var cmd = [ ConfigDir + "/scripts/" + mailscript ]
994 log(LogCritical, "me", cmd)
1003 ### Access Object Attributes at Runtime <a id="access-object-attributes-at-runtime"></a>
1005 The [Object Accessor Functions](18-library-reference.md#object-accessor-functions)
1006 can be used to retrieve references to other objects by name.
1008 This allows you to access configuration and runtime object attributes. A detailed
1009 list can be found [here](09-object-types.md#object-types).
1011 #### Access Object Attributes at Runtime: Cluster Check <a id="access-object-attributes-at-runtime-cluster-check"></a>
1013 This is a simple cluster example for accessing two host object states and calculating a virtual
1014 cluster state and output:
1017 object Host "cluster-host-01" {
1018 check_command = "dummy"
1019 vars.dummy_state = 2
1020 vars.dummy_text = "This host is down."
1023 object Host "cluster-host-02" {
1024 check_command = "dummy"
1025 vars.dummy_state = 0
1026 vars.dummy_text = "This host is up."
1029 object Host "cluster" {
1030 check_command = "dummy"
1031 vars.cluster_nodes = [ "cluster-host-01", "cluster-host-02" ]
1033 vars.dummy_state = {{
1036 var cluster_nodes = macro("$cluster_nodes$")
1038 for (node in cluster_nodes) {
1039 if (get_host(node).state > 0) {
1046 if (up_count >= down_count) {
1047 return 0 //same up as down -> UP
1049 return 2 //something is broken
1053 vars.dummy_text = {{
1054 var output = "Cluster hosts:\n"
1055 var cluster_nodes = macro("$cluster_nodes$")
1057 for (node in cluster_nodes) {
1058 output += node + ": " + get_host(node).last_check_result.output + "\n"
1066 #### Time Dependent Thresholds <a id="access-object-attributes-at-runtime-time-dependent-thresholds"></a>
1068 The following example sets time dependent thresholds for the load check based on the current
1069 time of the day compared to the defined time period.
1072 object TimePeriod "backup" {
1074 monday = "02:00-03:00"
1075 tuesday = "02:00-03:00"
1076 wednesday = "02:00-03:00"
1077 thursday = "02:00-03:00"
1078 friday = "02:00-03:00"
1079 saturday = "02:00-03:00"
1080 sunday = "02:00-03:00"
1084 object Host "webserver-with-backup" {
1085 check_command = "hostalive"
1086 address = "127.0.0.1"
1089 object Service "webserver-backup-load" {
1090 check_command = "load"
1091 host_name = "webserver-with-backup"
1093 vars.load_wload1 = {{
1094 if (get_time_period("backup").is_inside) {
1100 vars.load_cload1 = {{
1101 if (get_time_period("backup").is_inside) {
1111 ## Advanced Value Types <a id="advanced-value-types"></a>
1113 In addition to the default value types Icinga 2 also uses a few other types
1114 to represent its internal state. The following types are exposed via the [API](12-icinga2-api.md#icinga2-api).
1116 ### CheckResult <a id="advanced-value-types-checkresult"></a>
1118 Name | Type | Description
1119 --------------------------|-----------------------|----------------------------------
1120 exit\_status | Number | The exit status returned by the check execution.
1121 output | String | The check output.
1122 performance\_data | Array | Array of [performance data values](08-advanced-topics.md#advanced-value-types-perfdatavalue).
1123 check\_source | String | Name of the node executing the check.
1124 state | Number | The current state (0 = OK, 1 = WARNING, 2 = CRITICAL, 3 = UNKNOWN).
1125 command | Value | Array of command with shell-escaped arguments or command line string.
1126 execution\_start | Timestamp | Check execution start time (as a UNIX timestamp).
1127 execution\_end | Timestamp | Check execution end time (as a UNIX timestamp).
1128 schedule\_start | Timestamp | Scheduled check execution start time (as a UNIX timestamp).
1129 schedule\_end | Timestamp | Scheduled check execution end time (as a UNIX timestamp).
1130 active | Boolean | Whether the result is from an active or passive check.
1131 vars\_before | Dictionary | Internal attribute used for calculations.
1132 vars\_after | Dictionary | Internal attribute used for calculations.
1133 ttl | Number | Time-to-live duration in seconds for this check result. The next expected check result is `now + ttl` where freshness checks are executed.
1135 ### PerfdataValue <a id="advanced-value-types-perfdatavalue"></a>
1137 Icinga 2 parses performance data strings returned by check plugins and makes the information available to external interfaces (e.g. [GraphiteWriter](09-object-types.md#objecttype-graphitewriter) or the [Icinga 2 API](12-icinga2-api.md#icinga2-api)).
1139 Name | Type | Description
1140 --------------------------|-----------------------|----------------------------------
1141 label | String | Performance data label.
1142 value | Number | Normalized performance data value without unit.
1143 counter | Boolean | Enabled if the original value contains `c` as unit. Defaults to `false`.
1144 unit | String | Unit of measurement (`seconds`, `bytes`. `percent`) according to the [plugin API](05-service-monitoring.md#service-monitoring-plugin-api).
1145 crit | Value | Critical threshold value.
1146 warn | Value | Warning threshold value.
1147 min | Value | Minimum value returned by the check.
1148 max | Value | Maximum value returned by the check.