use a catalog zone to generate the ${ZONES} list

1 files changed, 41 insertions, 0 deletions

diff --git a/bin/get_catalog b/bin/get_catalog
new file mode 100755
index 0000000..d9e744b
--- /dev/null
+++ b/bin/get_catalog
@@ -0,0 +1,41 @@
+#! /bin/sh
+#
+# Fetch the catalog zone '$1' from the server '$2' and print a list of zones.
+
+set -e
+
+catalog="$1"
+server="$2"
+
+tempfile="$(mktemp -t catalog)"
+trap 'rm $tempfile' 0
+
+if ! dig "$catalog" axfr @"$server" +noall +answer >"$tempfile"; then
+	printf >&2 '%s: query failed\n' "$0"
+	exit 1
+fi
+
+# Make sure the result has an SOA, otherwise the query failed.
+if ! awk <"$tempfile" "
+BEGIN {
+	exitcode=1
+}
+
+\$1 == \"$catalog.\" && \$4 == \"SOA\" {
+	exitcode=0
+}
+
+END {
+	exit exitcode
+}
+"; then
+	printf >&2 '%s: no SOA found in zone; transfer failed?\n' "$0"
+	exit 1
+fi
+
+awk <"$tempfile" "
+\$1 ~ /zones.$catalog/ && \$4 == \"PTR\" {
+	zone = \$5
+	sub(/\\.$/, \"\", zone)
+	print zone
+}"