I couldn’t find an Icinga2 config file language sensitive editor for Kate, so I’ve put one together (attached). You just need to unzip the XML file from the attachment, and put it into the relevant directory - see https://docs.kde.org/stable5/en/kate/katepart/highlight.html:
.xmlhighlight definition files are located in
org.kde.syntax-highlighting/syntax/in your user folder found with
qtpaths --paths GenericDataLocationwhich usually are
HTH someone else.
icinga2.zip (3.0 KB)