Don't use persisted data until we are sure it matches

ipam/allocator.go

@@ -876,11 +876,13 @@ func (alloc *Allocator) loadPersistedData() {
 	if err != nil {
 		alloc.fatalf("Error loading persisted peer name: %s", err)
 	}
-	ringFound, err := alloc.db.Load(ringIdent, &alloc.ring)
+	var persistedRing *ring.Ring
+	ringFound, err := alloc.db.Load(ringIdent, &persistedRing)
 	if err != nil {
 		alloc.fatalf("Error loading persisted IPAM data: %s", err)
 	}
-	ownedFound, err := alloc.db.Load(ownedIdent, &alloc.owned)
+	var persistedOwned map[string]ownedData
+	ownedFound, err := alloc.db.Load(ownedIdent, &persistedOwned)
 	if err != nil {
 		alloc.fatalf("Error loading persisted address data: %s", err)
 	}
@@ -891,9 +893,11 @@ func (alloc *Allocator) loadPersistedData() {
 				if len(alloc.seed) != 0 {
 					alloc.infof("Found persisted IPAM data, ignoring supplied IPAM seed")
 				}
+				alloc.ring = persistedRing
 				alloc.space.UpdateRanges(alloc.ring.OwnedRanges())
 			}
 			if ownedFound {
+				alloc.owned = persistedOwned
 				for _, d := range alloc.owned {
 					for _, cidr := range d.Cidrs {
 						alloc.space.Claim(cidr.Addr)

test/380_ipam_seed_2_test.sh

@@ -19,4 +19,12 @@ weave_on $HOST2 connect $HOST1
 assert_raises "exec_on $HOST1 c1 $PING c2"
 assert_raises "exec_on $HOST2 c2 $PING c1"
 
+# Now restart one router with a different peername
+docker_on $HOST2 rm -f c2 >/dev/null
+weave_on $HOST2 forget $HOST1
+weave_on $HOST2 stop
+weave_on $HOST2 launch --name ::3
+# Check that this host has not retained the previous IPAM data
+assert "weave_on $HOST2 status ipam" ""
+
 end_suite