libnet: Use Endpoint.dnsNames to create DNS records

Instead of special-casing anonymous endpoints, use the list of DNS names
associated to the endpoint.

`(*Endpoint).isAnonymous()` has no more uses, so let's delete it.

Signed-off-by: Albin Kerouanton <albinker@gmail.com>

libnetwork/agent.go

@@ -598,7 +598,7 @@ func (ep *Endpoint) deleteDriverInfoFromCluster() error {
 }
 
 func (ep *Endpoint) addServiceInfoToCluster(sb *Sandbox) error {
-	if len(ep.myAliases) == 0 && ep.isAnonymous() || ep.Iface() == nil || ep.Iface().Address() == nil {
+	if len(ep.dnsNames) == 0 || ep.Iface() == nil || ep.Iface().Address() == nil {
 		return nil
 	}
 
@@ -628,10 +628,8 @@ func (ep *Endpoint) addServiceInfoToCluster(sb *Sandbox) error {
 		return nil
 	}
 
-	name := ep.Name()
-	if ep.isAnonymous() {
-		name = ep.MyAliases()[0]
-	}
+	dnsNames := ep.getDNSNames()
+	primaryDNSName, dnsAliases := dnsNames[0], dnsNames[1:]
 
 	var ingressPorts []*PortConfig
 	if ep.svcID != "" {
@@ -640,24 +638,24 @@ func (ep *Endpoint) addServiceInfoToCluster(sb *Sandbox) error {
 		if n.ingress {
 			ingressPorts = ep.ingressPorts
 		}
-		if err := n.getController().addServiceBinding(ep.svcName, ep.svcID, n.ID(), ep.ID(), name, ep.virtualIP, ingressPorts, ep.svcAliases, ep.myAliases, ep.Iface().Address().IP, "addServiceInfoToCluster"); err != nil {
+		if err := n.getController().addServiceBinding(ep.svcName, ep.svcID, n.ID(), ep.ID(), primaryDNSName, ep.virtualIP, ingressPorts, ep.svcAliases, dnsAliases, ep.Iface().Address().IP, "addServiceInfoToCluster"); err != nil {
 			return err
 		}
 	} else {
 		// This is a container simply attached to an attachable network
-		if err := n.getController().addContainerNameResolution(n.ID(), ep.ID(), name, ep.myAliases, ep.Iface().Address().IP, "addServiceInfoToCluster"); err != nil {
+		if err := n.getController().addContainerNameResolution(n.ID(), ep.ID(), primaryDNSName, dnsAliases, ep.Iface().Address().IP, "addServiceInfoToCluster"); err != nil {
 			return err
 		}
 	}
 
 	buf, err := proto.Marshal(&EndpointRecord{
-		Name:            name,
+		Name:            primaryDNSName,
 		ServiceName:     ep.svcName,
 		ServiceID:       ep.svcID,
 		VirtualIP:       ep.virtualIP.String(),
 		IngressPorts:    ingressPorts,
 		Aliases:         ep.svcAliases,
-		TaskAliases:     ep.myAliases,
+		TaskAliases:     dnsAliases,
 		EndpointIP:      ep.Iface().Address().IP.String(),
 		ServiceDisabled: false,
 	})
@@ -676,7 +674,7 @@ func (ep *Endpoint) addServiceInfoToCluster(sb *Sandbox) error {
 }
 
 func (ep *Endpoint) deleteServiceInfoFromCluster(sb *Sandbox, fullRemove bool, method string) error {
-	if len(ep.myAliases) == 0 && ep.isAnonymous() {
+	if len(ep.dnsNames) == 0 {
 		return nil
 	}
 
@@ -699,10 +697,8 @@ func (ep *Endpoint) deleteServiceInfoFromCluster(sb *Sandbox, fullRemove bool, m
 		return nil
 	}
 
-	name := ep.Name()
-	if ep.isAnonymous() {
-		name = ep.MyAliases()[0]
-	}
+	dnsNames := ep.getDNSNames()
+	primaryDNSName, dnsAliases := dnsNames[0], dnsNames[1:]
 
 	// First update the networkDB then locally
 	if fullRemove {
@@ -720,12 +716,12 @@ func (ep *Endpoint) deleteServiceInfoFromCluster(sb *Sandbox, fullRemove bool, m
 			if n.ingress {
 				ingressPorts = ep.ingressPorts
 			}
-			if err := n.getController().rmServiceBinding(ep.svcName, ep.svcID, n.ID(), ep.ID(), name, ep.virtualIP, ingressPorts, ep.svcAliases, ep.myAliases, ep.Iface().Address().IP, "deleteServiceInfoFromCluster", true, fullRemove); err != nil {
+			if err := n.getController().rmServiceBinding(ep.svcName, ep.svcID, n.ID(), ep.ID(), primaryDNSName, ep.virtualIP, ingressPorts, ep.svcAliases, dnsAliases, ep.Iface().Address().IP, "deleteServiceInfoFromCluster", true, fullRemove); err != nil {
 				return err
 			}
 		} else {
 			// This is a container simply attached to an attachable network
-			if err := n.getController().delContainerNameResolution(n.ID(), ep.ID(), name, ep.myAliases, ep.Iface().Address().IP, "deleteServiceInfoFromCluster"); err != nil {
+			if err := n.getController().delContainerNameResolution(n.ID(), ep.ID(), primaryDNSName, dnsAliases, ep.Iface().Address().IP, "deleteServiceInfoFromCluster"); err != nil {
 				return err
 			}
 		}

libnetwork/endpoint.go

@@ -308,10 +308,15 @@ func (ep *Endpoint) Network() string {
 	return ep.network.name
 }
 
-func (ep *Endpoint) isAnonymous() bool {
+// getDNSNames returns a copy of the DNS names associated to this endpoint. The first entry is the one used for PTR
+// records.
+func (ep *Endpoint) getDNSNames() []string {
 	ep.mu.Lock()
 	defer ep.mu.Unlock()
-	return ep.anonymous
+
+	dnsNames := make([]string, len(ep.dnsNames))
+	copy(dnsNames, ep.dnsNames)
+	return dnsNames
 }
 
 // isServiceEnabled check if service is enabled on the endpoint

libnetwork/network.go

@@ -1302,8 +1302,6 @@ func (n *Network) updateSvcRecord(ep *Endpoint, isAdd bool) {
 	}
 
 	var ipv6 net.IP
-	epName := ep.Name()
-	myAliases := ep.MyAliases()
 	if iface.AddressIPv6() != nil {
 		ipv6 = iface.AddressIPv6().IP
 	}
@@ -1312,30 +1310,17 @@ func (n *Network) updateSvcRecord(ep *Endpoint, isAdd bool) {
 	if serviceID == "" {
 		serviceID = ep.ID()
 	}
+
+	dnsNames := ep.getDNSNames()
 	if isAdd {
-		// If anonymous endpoint has an alias use the first alias
-		// for ip->name mapping. Not having the reverse mapping
-		// breaks some apps
-		if ep.isAnonymous() {
-			if len(myAliases) > 0 {
-				n.addSvcRecords(ep.ID(), myAliases[0], serviceID, iface.Address().IP, ipv6, true, "updateSvcRecord")
-			}
-		} else {
-			n.addSvcRecords(ep.ID(), epName, serviceID, iface.Address().IP, ipv6, true, "updateSvcRecord")
-		}
-		for _, alias := range myAliases {
-			n.addSvcRecords(ep.ID(), alias, serviceID, iface.Address().IP, ipv6, false, "updateSvcRecord")
+		for i, dnsName := range dnsNames {
+			ipMapUpdate := i == 0 // ipMapUpdate indicates whether PTR records should be updated.
+			n.addSvcRecords(ep.ID(), dnsName, serviceID, iface.Address().IP, ipv6, ipMapUpdate, "updateSvcRecord")
 		}
 	} else {
-		if ep.isAnonymous() {
-			if len(myAliases) > 0 {
-				n.deleteSvcRecords(ep.ID(), myAliases[0], serviceID, iface.Address().IP, ipv6, true, "updateSvcRecord")
-			}
-		} else {
-			n.deleteSvcRecords(ep.ID(), epName, serviceID, iface.Address().IP, ipv6, true, "updateSvcRecord")
-		}
-		for _, alias := range myAliases {
-			n.deleteSvcRecords(ep.ID(), alias, serviceID, iface.Address().IP, ipv6, false, "updateSvcRecord")
+		for i, dnsName := range dnsNames {
+			ipMapUpdate := i == 0 // ipMapUpdate indicates whether PTR records should be updated.
+			n.deleteSvcRecords(ep.ID(), dnsName, serviceID, iface.Address().IP, ipv6, ipMapUpdate, "updateSvcRecord")
 		}
 	}
 }
@@ -1374,6 +1359,7 @@ func delNameToIP(svcMap *setmatrix.SetMatrix[svcMapEntry], name, serviceID strin
 	})
 }
 
+// TODO(aker): remove ipMapUpdate param and add a proper method dedicated to update PTR records.
 func (n *Network) addSvcRecords(eID, name, serviceID string, epIP, epIPv6 net.IP, ipMapUpdate bool, method string) {
 	// Do not add service names for ingress network as this is a
 	// routing only network