Include statements with non-JSON extensions in Kea CA config

Stork supports the include statements in the Kea Control Agent configuration, but only if the included file has a .json extension. Kea allows any extensions. If the Kea Control Agent configuration contains the include statement with the non-JSON file, Stork throws an error and rejects the particular Kea.

The problem was reported on our mailing list on 2023-05-11:

The Stork Agent is not happy when a KEA configuration file has an include statement in it. This is the error I see on the syslog:

level="error" msg="Invalid Kea Control Agent config" file="              kea.go:215  " error="Cannot parse Kea Control Agent config file: problem parsing Kea configuration: invalid character '<' looking for beginning of object key string: invalid character '<' looking for beginning of object key string"

And the configuration file it is trying to read is starting as:

{
   "Control-agent": {
       <?include "/mnt/data/etc/kea/local-ctrl-agent.include"?>

Hmm… KEA accepts the .include extension though, so shouldn’t Stork accept what KEA accepts?