Add a statistics channel check in the forward system test

Check that the fix in the previous commit works and that the
'ServerQuota' counter in the statistics channel is still unset
after a SERVFAIL result in a 'forward only' zone.

bin/tests/system/forward/clean.sh

@@ -19,6 +19,7 @@ rm -f ./*/named.memstats
 rm -f ./*/named.run ./*/named.run.prev ./*/ans.run
 rm -f ./*/named_dump.db
 rm -f ./ans*/query.log
+rm -f ./statschannel.out.*
 rm -f ./dig.out.*
 rm -f ./ns*/managed-keys.bind*
 rm -f ./ns*/trusted.conf

bin/tests/system/forward/ns4/named.conf.in

@@ -29,6 +29,8 @@ options {
 
 trust-anchors { };
 
+statistics-channels { inet 10.53.0.4 port @EXTRAPORT1@ allow { localhost; }; };
+
 zone "." {
 	type hint;
 	file "root.db";

bin/tests/system/forward/tests.sh

@@ -164,6 +164,15 @@ grep "SERVFAIL" dig.out.$n.f2 >/dev/null || ret=1
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=$((status + ret))
 
+# GL#1793
+n=$((n + 1))
+echo_i "checking that the 'serverquota' counter isn't increased because of the SERVFAIL in the previous check ($n)"
+ret=0
+"${CURL}" "http://10.53.0.4:${EXTRAPORT1}/json/v1" 2>/dev/null >statschannel.out.$n
+grep -F "ServerQuota" statschannel.out.$n >/dev/null && ret=1
+if [ $ret != 0 ]; then echo_i "failed"; fi
+status=$((status + ret))
+
 n=$((n + 1))
 echo_i "checking for negative caching of forwarder response ($n)"
 # prime the cache, shutdown the forwarder then check that we can