Service Discovery reuse name and serviceBindings deletion

- Added logic to handle name reuse from different services
- Moved the deletion from the serviceBindings map at the end
  of the rmServiceBindings body to avoid race with new services

Signed-off-by: Flavio Crisciani <flavio.crisciani@docker.com>

common/setmatrix.go

@@ -28,6 +28,8 @@ type SetMatrix interface {
 	// String returns the string version of the set, empty otherwise
 	// returns false if the set is not present
 	String(key string) (string, bool)
+	// Returns all the keys in the map
+	Keys() []string
 }
 
 type setMatrix struct {
@@ -121,3 +123,13 @@ func (s *setMatrix) String(key string) (string, bool) {
 	}
 	return set.String(), ok
 }
+
+func (s *setMatrix) Keys() []string {
+	s.Lock()
+	defer s.Unlock()
+	keys := make([]string, 0, len(s.matrix))
+	for k := range s.matrix {
+		keys = append(keys, k)
+	}
+	return keys
+}

libnetwork_internal_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/docker/libnetwork/driverapi"
 	"github.com/docker/libnetwork/ipamapi"
 	"github.com/docker/libnetwork/netlabel"
+	"github.com/docker/libnetwork/netutils"
 	"github.com/docker/libnetwork/testutils"
 	"github.com/docker/libnetwork/types"
 )
@@ -379,8 +380,8 @@ func TestSRVServiceQuery(t *testing.T) {
 	}
 
 	sr := svcInfo{
-		svcMap:     make(map[string][]net.IP),
-		svcIPv6Map: make(map[string][]net.IP),
+		svcMap:     common.NewSetMatrix(),
+		svcIPv6Map: common.NewSetMatrix(),
 		ipMap:      common.NewSetMatrix(),
 		service:    make(map[string][]servicePorts),
 	}
@@ -437,6 +438,119 @@ func TestSRVServiceQuery(t *testing.T) {
 	}
 }
 
+func TestServiceVIPReuse(t *testing.T) {
+	c, err := New()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Stop()
+
+	n, err := c.NewNetwork("bridge", "net1", "", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := n.Delete(); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	ep, err := n.CreateEndpoint("testep")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sb, err := c.NewSandbox("c1")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := sb.Delete(); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	err = ep.Join(sb)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Add 2 services with same name but different service ID to share the same VIP
+	n.(*network).addSvcRecords("ep1", "service_test", "serviceID1", net.ParseIP("192.168.0.1"), net.IP{}, true, "test")
+	n.(*network).addSvcRecords("ep2", "service_test", "serviceID2", net.ParseIP("192.168.0.1"), net.IP{}, true, "test")
+
+	ipToResolve := netutils.ReverseIP("192.168.0.1")
+
+	ipList, _ := n.(*network).ResolveName("service_test", types.IPv4)
+	if len(ipList) == 0 {
+		t.Fatal("There must be the VIP")
+	}
+	if len(ipList) != 1 {
+		t.Fatal("It must return only 1 VIP")
+	}
+	if ipList[0].String() != "192.168.0.1" {
+		t.Fatal("The service VIP is 192.168.0.1")
+	}
+	name := n.(*network).ResolveIP(ipToResolve)
+	if name == "" {
+		t.Fatal("It must return a name")
+	}
+	if name != "service_test.net1" {
+		t.Fatalf("It must return the service_test.net1 != %s", name)
+	}
+
+	// Delete service record for one of the services, the IP should remain because one service is still associated with it
+	n.(*network).deleteSvcRecords("ep1", "service_test", "serviceID1", net.ParseIP("192.168.0.1"), net.IP{}, true, "test")
+	ipList, _ = n.(*network).ResolveName("service_test", types.IPv4)
+	if len(ipList) == 0 {
+		t.Fatal("There must be the VIP")
+	}
+	if len(ipList) != 1 {
+		t.Fatal("It must return only 1 VIP")
+	}
+	if ipList[0].String() != "192.168.0.1" {
+		t.Fatal("The service VIP is 192.168.0.1")
+	}
+	name = n.(*network).ResolveIP(ipToResolve)
+	if name == "" {
+		t.Fatal("It must return a name")
+	}
+	if name != "service_test.net1" {
+		t.Fatalf("It must return the service_test.net1 != %s", name)
+	}
+
+	// Delete again the service using the previous service ID, nothing should happen
+	n.(*network).deleteSvcRecords("ep2", "service_test", "serviceID1", net.ParseIP("192.168.0.1"), net.IP{}, true, "test")
+	ipList, _ = n.(*network).ResolveName("service_test", types.IPv4)
+	if len(ipList) == 0 {
+		t.Fatal("There must be the VIP")
+	}
+	if len(ipList) != 1 {
+		t.Fatal("It must return only 1 VIP")
+	}
+	if ipList[0].String() != "192.168.0.1" {
+		t.Fatal("The service VIP is 192.168.0.1")
+	}
+	name = n.(*network).ResolveIP(ipToResolve)
+	if name == "" {
+		t.Fatal("It must return a name")
+	}
+	if name != "service_test.net1" {
+		t.Fatalf("It must return the service_test.net1 != %s", name)
+	}
+
+	// Delete now using the second service ID, now all the entries should be gone
+	n.(*network).deleteSvcRecords("ep2", "service_test", "serviceID2", net.ParseIP("192.168.0.1"), net.IP{}, true, "test")
+	ipList, _ = n.(*network).ResolveName("service_test", types.IPv4)
+	if len(ipList) != 0 {
+		t.Fatal("All the VIPs should be gone now")
+	}
+	name = n.(*network).ResolveIP(ipToResolve)
+	if name != "" {
+		t.Fatalf("It must return empty no more services associated, instead:%s", name)
+	}
+}
+
 func TestIpamReleaseOnNetDriverFailures(t *testing.T) {
 	if !testutils.IsRunningInContainer() {
 		defer testutils.SetupTestOSContext(t)()