The BIND9 wildcard address is not handled properly.

The issue was reported on our mailing list.

The BIND 9 control channel allows the wildcard address ("*") to be specified and listened to on all interfaces. Example:

controls {
	inet * allow { localhost; };
};

In this case, the Stork agent should connect to BIND 9 over the localhost address. We have a dedicated condition for it in the function that parses the BIND 9 configuration (parseInetSpec - backend/agent/bind9.go:271-273):

	if address == "*" {
		address = "localhost"
	}

So, it should work, but it doesn't. The Stork agent tries to establish a connection to the 0.0.0.0 address, and it fails.

The Stork agent doesn't read the BIND 9 configuration directly. Instead, it calls the named-checkconf command, which combines the main config file and all references into a single output. This command seems to also resolve the wildcard symbol to 0.0.0.0.

The original named.conf entry:

controls {
	inet * allow { localhost; };
};

The named-checkconf output:

controls {
        inet 0.0.0.0 allow {
                "localhost";
        };
};

We need to handle this case properly. Tested on BIND 9.18.