Merge pull request #1358 from weaveworks/1357-dns-reverse-tombstone

Make reverse dns lookups honor tombstones.

nameserver/nameserver.go

@@ -121,7 +121,7 @@ func (n *Nameserver) ReverseLookup(ip address.Address) (string, error) {
 	defer n.RUnlock()
 
 	match, err := n.entries.first(func(e *Entry) bool {
-		return e.Addr == ip
+		return e.Tombstone == 0 && e.Addr == ip
 	})
 	if err != nil {
 		return "", err

test/265_dns_reverse_test.sh

@@ -0,0 +1,23 @@
+#! /bin/bash
+
+. ./config.sh
+
+IP=10.2.0.67
+
+start_suite "Reverse DNS test"
+
+weave_on $HOST1 launch
+start_container_with_dns $HOST1 --name=c1
+
+# We try names in alphabetical order; this is because the
+# nameserver keeps entries sorted by hostname then address,
+# so by starting with acontainer then trying bcontainer,
+# we're guaranteed to have to ignore a tombstone to get the
+# right result.
+for name in acontainer bcontainer ccontainer; do
+    start_container $HOST1 $IP/24 --name=$name
+    assert_dns_record $HOST1 c1 $name.weave.local $IP
+    rm_containers $HOST1 $name
+done
+
+end_suite

test/config.sh

@@ -167,9 +167,9 @@ container_ip() {
 
 # assert_dns_record <host> <container> <name> [<ip> ...]
 assert_dns_record() {
-    host=$1
-    container=$2
-    name=$3
+    local host=$1
+    local container=$2
+    local name=$3
     shift 3
     exp_ips_regex=$(echo "$@" | sed -e 's/ /\\\|/g')