Massive Clean-up of the Icinga custom_var (Services)
During one of my last sessions with a customer I had to deal with a very particular use case, where I couldn’t use the solution presented in my previous blog post (https://www.neteye-blog.com/2025/08/massive-update-of-the-icinga-custom_var-host-services/).
In this new scenario, the customer wanted to clean up a custom_var linked to a service, whose value, inherited from the host, had then been overwritten at the service level.
To overcome this obstacle, I worked directly with Director DB on the icinga_host_var table. At first glance, it may seem strange that in order to remove a custom_var of a service you have to modify the table related to the variables of a host, but this is the way custom_vars are handled in Icinga.
In this example I’ll show you how to clean up a variable foobar1 with an empty array value structured as [“”] (if you have a specific value consider what you want to remove).
To do this, do an UPDATE in the icinga_host_var table. We want to look for all instances of custom_var with the name (varname) equal to “_override_servicevars” and that contain as a value (varvalue) our variable to be removed, i.e. “foobar1”:[“”],
Once an occurrence has been found, we perform a REPLACE action for the unwanted value.
The UPDATE to be launched will therefore be the following:
UPDATE icinga_host_var
SET varvalue=REPLACE (varvalue,'"foobar1":[""],','')
where
varname="_override_servicevars" and
varvalue LIKE '%"foobar1":[""],%
Following this query, launch a further update in case this value is at the end of the list.
UPDATE icinga_host_var
SET varvalue=REPLACE (varvalue,'"foobar1":[""]','')
where
varname="_override_servicevars" and
varvalue LIKE '%"foobar1":[""]%'
By doing so, all unwanted values will then be cleaned up, bringing our services to the desired states. If you’re not familiar with DB operations, it’s advisable to make a backup of the table in order to have a recovery point.
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Attilio Broglio
Author
