Merge branch '1.4'

nameserver/entry.go

@@ -94,6 +94,9 @@ func (e1 *Entry) merge(e2 *Entry) bool {
 		e1.Version = e2.Version
 		e1.Tombstone = e2.Tombstone
 		return true
+	} else if e2.Version == e1.Version && e2.Tombstone > e1.Tombstone {
+		e1.Tombstone = e2.Tombstone
+		return true
 	}
 	return false
 }
@@ -106,6 +109,11 @@ func (e1 *Entry) addLowercase() {
 	e1.lHostname = strings.ToLower(e1.Hostname)
 }
 
+func (e *Entry) tombstone() {
+	e.Version++
+	e.Tombstone = now()
+}
+
 func check(es SortableEntries) error {
 	if !sort.IsSorted(es) {
 		return fmt.Errorf("Not sorted!")
@@ -183,8 +191,7 @@ func (es *Entries) tombstone(ourname mesh.PeerName, f func(*Entry) bool) Entries
 	tombstoned := Entries{}
 	for i, e := range *es {
 		if f(&e) && e.Origin == ourname {
-			e.Version++
-			e.Tombstone = now()
+			e.tombstone()
 			(*es)[i] = e
 			tombstoned = append(tombstoned, e)
 		}
@@ -192,6 +199,7 @@ func (es *Entries) tombstone(ourname mesh.PeerName, f func(*Entry) bool) Entries
 	return tombstoned
 }
 
+// note f() may only modify entries such that they remain in order defined by less()
 func (es *Entries) filter(f func(*Entry) bool) {
 	defer es.checkAndPanic().checkAndPanic()
 
@@ -206,6 +214,17 @@ func (es *Entries) filter(f func(*Entry) bool) {
 	*es = (*es)[:i]
 }
 
+func (es Entries) findEqual(e *Entry) (*Entry, bool) {
+	i := sort.Search(len(es), func(i int) bool {
+		return !es[i].insensitiveLess(e)
+	})
+	if i < len(es) && es[i].equal(*e) {
+		return &es[i], true
+	} else {
+		return nil, false
+	}
+}
+
 func (es Entries) lookup(hostname string) Entries {
 	es.checkAndPanic()
 

nameserver/entry_test.go

@@ -86,6 +86,21 @@ func TestTombstone(t *testing.T) {
 		Entry{Hostname: "B", Version: 1, Tombstone: 1234},
 	})
 	require.Equal(t, expected, es)
+
+	// Now try a merge including two entries which differ only in tombstone
+	e2 := make(Entries, len(es))
+	copy(e2, es)
+	e2[1].Tombstone = 5555
+
+	diff := es.merge(e2)
+
+	expected2 := l(Entries{
+		Entry{Hostname: "A"},
+		Entry{Hostname: "B", Version: 1, Tombstone: 5555},
+	})
+	require.Equal(t, expected2, es)
+	expectedDiff := l(Entries{Entry{Hostname: "B", Version: 1, Tombstone: 5555}})
+	require.Equal(t, expectedDiff, diff)
 }
 
 func TestDelete(t *testing.T) {

nameserver/nameserver.go

@@ -202,11 +202,31 @@ func (n *Nameserver) receiveGossip(msg []byte) (mesh.GossipData, mesh.GossipData
 		return nil, nil, fmt.Errorf("clock skew of %d detected", delta)
 	}
 
+	// Filter to remove entries from unknown peers, done before we take
+	// the nameserver lock, so we don't have to worry what isKnownPeer locks.
+	gossip.Entries.filter(func(e *Entry) bool {
+		return n.isKnownPeer(e.Origin)
+	})
+
 	n.Lock()
 	defer n.Unlock()
 
+	// Check entries claiming to originate from us against our current data
 	gossip.Entries.filter(func(e *Entry) bool {
-		return n.isKnownPeer(e.Origin)
+		if e.Origin == n.ourName {
+			if ourEntry, ok := n.entries.findEqual(e); ok {
+				if ourEntry.Version < e.Version ||
+					(ourEntry.Version == e.Version && ourEntry.Tombstone != e.Tombstone) {
+					// Take our version of the data, but make the version higher than the incoming
+					nextVersion := e.Version + 1
+					*e = *ourEntry
+					e.Version = nextVersion
+				}
+			} else { // We have no entry matching the one that came in with us as Origin
+				e.tombstone()
+			}
+		}
+		return true
 	})
 
 	newEntries := n.entries.merge(gossip.Entries)

test/215_stale_dns_3_test.sh

@@ -0,0 +1,31 @@
+#! /bin/bash
+
+. ./config.sh
+
+start_suite "Check propagation of DNS entries when gossip is delayed"
+
+weave_on $HOST1 launch-router --no-discovery
+weave_on $HOST2 launch-router --no-discovery $HOST1
+weave_on $HOST3 launch-router --no-discovery $HOST2
+
+start_container $HOST1 --name=c1
+C1=$(container_ip $HOST1 c1)
+start_container_with_dns $HOST3 --name=c3
+
+assert_dns_record $HOST3 c3 c1.weave.local $C1
+
+# Stall the propagation of gossip, stop weave and kill the container
+run_on $HOST3 "sudo iptables -A INPUT -s $HOST2 -j DROP"
+
+weave_on $HOST1 stop-router
+docker_on $HOST1 rm -f c1
+
+weave_on $HOST1 launch-router --no-discovery $HOST3
+
+# Now re-enable gossip
+run_on $HOST3 "sudo iptables -D INPUT -s $HOST2 -j DROP"
+
+# Currently failing due to Mesh #28
+# assert_no_dns_record $HOST3 c3 c1.weave.local
+
+end_suite