Check binary BIND zonefile for record

Question

I'm running BIND as a DNS slave and want to check if the zone contains the correct records after an update on the master. However, the zone file appears to be binary:

root@server:/var/lib/bind/zones# file db.example.org
db.example.org: data
root@server:/var/lib/bind/zones# hexdump -C db.example.org
00000000  00 00 00 02 00 00 00 01  5f bc cb d0 00 00 00 00  |........_.......|
00000010  00 00 00 00 00 00 00 00  00 00 00 72 00 01 00 06  |...........r....|
...

Is there a way to check this file for the presence (or absence) of particular records?

Answer 1

BIND comes with a tool named-compilezone that allows you to convert a zone file from binary to text and vice versa.

named-compilezone -f IN_FORMAT -F OUT_FORMAT -o OUT_FILE DOMAIN /PATH/TO/ZONEFILE

To convert a zonefile from binary to text use raw as the input format and text as the output format. If you want the output on STDOUT instead of a file use - as the output file name. Add the option -q to suppress status output.

Something like this:

named-compilezone -q -f raw -F text -o - example.org /var/lib/bind/zones/db.example.org

should produce output like this:

example.org.      300 IN SOA  example.org. admin.example.org. 2020112400 10800 3600 604800 3600
example.org.      300 IN NS   ns1.example.org.
example.org.      300 IN NS   ns2.example.org.
foo.example.org.  300 IN A    192.168.23.42
...

You can then process the output with the usual text tools (grep, sed, awk, perl, ...). The presence of a particular A record could for instance be verified like this:

... | grep "^foo\.example\.org.* IN A"