1. Using Multisite as a Web Service
Check_MK Multisite can be used in scripting environment where you want to
- access current status data via HTTP
- execute commands liks setting downtimes via HTTP
Using the Multisite GUI for doing such things has some advantages over a direct access to the Livestatus socket, for example:
- Setups with more than one site will be handled by Multisite
- Authorization can be done on a fine-granular base
- Access via HTTP is more easily securable and proxy-able
2. Access to Views
Status data can be accessed via normal views. As an alternative to HTML you can get either JSON or Python formatted output. You do this by simply appending &output_format=json or &output_format=python to the URL of the view. When forming the URL you can use all filtering possibilities that the view provides. It is also possible to create specialized custom views used only as a web service. In order not to confuse the normal GUI users you should set the following two options:
- Hide this view from the sidebar
- do not show a context button to this view
3. Executing Commands
Executing commands on hosts and services is simply done by sending the same URLs that the user does when doing this interactively - but with a few modifications. The best way to generate such URL is first to switch off the sidebar by clicking on .
The following URL has been fetched from the browsers URL line when setting a 2-hours downtime on a service called Dummy on the host localhost (we folded the URL at &):
view.py?filled_in=actions &_transid=1354537808%2F207935917 &_do_actions=yes &actions=yes &filled_in=actions &service=Dummy &host=localhost &actions=yes &site= &view_name=service &_cusnot_comment=TEST &_ack_comment= &_comment= &_down_2h=2+hours &_down_from_date=2012-12-03 &_down_from_time=13%3A30 &_down_to_date=2012-12-03 &_down_to_time=15%3A30 &_down_minutes=60 &_down_duration=02%3A00 &_down_comment=TEST
The first important modification you need to do is to set transid to -1. The transaction ID is used to avoid multiple command executions when browser pages are reloaded.
But this change can only be made if you authenticate as a user which is authenticating with an automation secret. Normal user accounts can not use _transid=-1.
You can then further simplify the URL by removing input fields that have no influence on the command in question and remove any duplicates. Here is the resulting working URL:
view.py?_do_confirm=yes &_transid=-1 &_do_actions=yes &service=Dummy &host=localhost &site= &view_name=service &_down_2h=2+hours &_down_comment=TEST
Important variables that are needed in every automation command are:
|_do_confirm||yes||User confirmation: must be set to yes.|
|_do_actions||yes||Indicates action: must be set to yes|
|_transid||-1||Switches off replay detection|
|view_name||service, hoststatus||Name of the Multisite View.|
4. Automation Login
When running automation scripts using HTTP, the first thing you will run into is the question of authentication. If you are using basic HTTP authentication then the only way to go is to create a special user for the automation, set a password and use that password in your scripts.
If you are using the Check_MK login GUI then this does not work. And there is a much more elegant way - especially when your scripts run on the same machine as your OMD site.
This first step is to create an automation user. Here you do not set a password but a secret. This secret will be saved in a file in cleartext in the same directory as the user settings of that user. In OMD this is below the site in var/check_mk/web/USER/automation.secret. This file is readable only by owner and group.
If your script is running on the same host then it can simply read this file and you do not need to hardcode or configure the secret somewhere.
When calling the Multisite URL from your script you simply need to append the name of the automation user and this scecret in two URL variables:
|_username||Name of the automation user|
|_secret||Automation secret of that user|
Here is a commandline using curl in order to get the current open problems in JSON syntax:
user@host:~$ curl 'http://localhost/heute/check_mk/view.py?view_name=svcproblems &output_format=JSON&_username=auto&_secret=BLARBS@JQTAH@UWMBJXB' [ ["host","service_description","svc_plugin_output","svc_state_age","svc_check_ag... ["localhost","fs_/home","CRIT - 94.7% used (62.42 of 65.9 GB), (levels at 80.0/... ["localhost","LOG /var/log/Xorg.0.log","CRIT - 2 CRIT messages (Last worst: \"t... ["localhost","Multipath SDDN_S2A_9900_1308xxxxxxxx","CRIT - broken paths: 3:0:1... ]
Here is another example calling the create snapshot function to automatically create a snapshot from the given backup domains.
user@host> curl 'http://localhost/heute/check_mk/wato.py?mode=snapshot&_username= autouser&_secret=RPPVQD@EVYSPGBYDCKFO&snapshot_options_p_group_0_1=on &_create_snapshot&_transid=-1'
This command only stores the backup domain "Automatically detected services", which are identified by the parameter snapshot_options_p_group_0_1. If you want to determine the correct parameter name for other backup domains, please use the developer mode of your web-browser, e.g. firebug, to get the correct name of each check box.