unbound_munin: fix statistics after unbound restart / server reboot

"unbound-control stats" lists only query types that has been seen
after unbound restart. Munin requires list of all types ever seen,
or the generated graphs are mostly empty after restart.

Fix this by adding a state file with list of seen query types etc.

contrib/unbound_munin_

@@ -97,6 +97,7 @@ BSD
 
 . ${MUNIN_LIBDIR}/plugins/plugin.sh
 state="${MUNIN_PLUGSTATE}/unbound.state"
+seentags="${MUNIN_PLUGSTATE}/unbound-seentags.state"
 conf=${unbound_conf:-/usr/local/etc/unbound/unbound.conf}
 ctrl=${unbound_control:-/usr/local/sbin/unbound-control}
 warn=${spoof_warn:-1000}
@@ -119,6 +120,18 @@ get_value ( ) {
 	fi
 }
 
+# Update list of seen query types etc to seentags file. This is run while
+# holding the lock, after the state file is updated.
+update_seentags() {
+    tmplist="$(cat ${seentags} 2> /dev/null)
+num.query.type.A
+num.query.class.IN
+num.query.opcode.QUERY
+num.answer.rcode.NOERROR
+"
+    (echo "${tmplist}"; grep ^num ${state} | sed -e 's/=.*//') | sort -u > ${seentags}
+}
+
 # download the state from the unbound server.
 get_state ( ) {
 	# obtain lock for fetching the state
@@ -166,6 +179,7 @@ get_state ( ) {
 		rm -f $lock
 		exit 1
 	fi
+	update_seentags
 	rm -f $lock
 }
 
@@ -282,8 +296,7 @@ if test "$1" = "config" ; then
 		echo "graph_vlabel queries / \${graph_period}"
 		echo "graph_scale no"
 		echo "graph_category DNS"
-		for x in `grep "^num.query.type" $state`; do
-			nm=`echo $x | sed -e 's/=.*$//'`
+		for nm in `grep "^num.query.type" $seentags`; do
 			tp=`echo $nm | sed -e s/num.query.type.//`
 			p_config "$nm" "$tp" "ABSOLUTE"
 		done
@@ -295,8 +308,7 @@ if test "$1" = "config" ; then
 		echo "graph_vlabel queries / \${graph_period}"
 		echo "graph_scale no"
 		echo "graph_category DNS"
-		for x in `grep "^num.query.class" $state`; do
-			nm=`echo $x | sed -e 's/=.*$//'`
+		for nm in `grep "^num.query.class" $seentags`; do
 			tp=`echo $nm | sed -e s/num.query.class.//`
 			p_config "$nm" "$tp" "ABSOLUTE"
 		done
@@ -308,8 +320,7 @@ if test "$1" = "config" ; then
 		echo "graph_vlabel queries / \${graph_period}"
 		echo "graph_scale no"
 		echo "graph_category DNS"
-		for x in `grep "^num.query.opcode" $state`; do
-			nm=`echo $x | sed -e 's/=.*$//'`
+		for nm in `grep "^num.query.opcode" $seentags`; do
 			tp=`echo $nm | sed -e s/num.query.opcode.//`
 			p_config "$nm" "$tp" "ABSOLUTE"
 		done
@@ -321,8 +332,7 @@ if test "$1" = "config" ; then
 		echo "graph_vlabel answer packets / \${graph_period}"
 		echo "graph_scale no"
 		echo "graph_category DNS"
-		for x in `grep "^num.answer.rcode" $state`; do
-			nm=`echo $x | sed -e 's/=.*$//'`
+		for nm in `grep "^num.answer.rcode" $seentags`; do
 			tp=`echo $nm | sed -e s/num.answer.rcode.//`
 			p_config "$nm" "$tp" "ABSOLUTE"
 		done
@@ -465,27 +475,23 @@ memory)
 	done
 	;;
 by_type)
-	for x in `grep "^num.query.type" $state`; do
-		nm=`echo $x | sed -e 's/=.*$//'`
-		print_value_line $nm $x
+	for nm in `grep "^num.query.type" $seentags`; do
+		print_value $nm
 	done
 	;;
 by_class)
-	for x in `grep "^num.query.class" $state`; do
-		nm=`echo $x | sed -e 's/=.*$//'`
-		print_value_line $nm $x
+	for nm in `grep "^num.query.class" $seentags`; do
+		print_value $nm
 	done
 	;;
 by_opcode)
-	for x in `grep "^num.query.opcode" $state`; do
-		nm=`echo $x | sed -e 's/=.*$//'`
-		print_value_line $nm $x
+	for nm in `grep "^num.query.opcode" $seentags`; do
+		print_value $nm
 	done
 	;;
 by_rcode)
-	for x in `grep "^num.answer.rcode" $state`; do
-		nm=`echo $x | sed -e 's/=.*$//'`
-		print_value_line $nm $x
+	for nm in `grep "^num.answer.rcode" $seentags`; do
+		print_value $nm $x
 	done
 	print_value "num.answer.secure"
 	print_value "num.answer.bogus"