Add service virtual IP to sandbox's loopback address

Refreshed the PR: https://github.com/docker/libnetwork/pull/1585
Addressed comments suggesting to remove the IPAlias logic not anymore used

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

libnetwork/osl/interface_linux.go

@@ -26,7 +26,6 @@ type nwIface struct {
 	mac         net.HardwareAddr
 	address     *net.IPNet
 	addressIPv6 *net.IPNet
-	ipAliases   []*net.IPNet
 	llAddrs     []*net.IPNet
 	routes      []*net.IPNet
 	bridge      bool
@@ -97,13 +96,6 @@ func (i *nwIface) LinkLocalAddresses() []*net.IPNet {
 	return i.llAddrs
 }
 
-func (i *nwIface) IPAliases() []*net.IPNet {
-	i.Lock()
-	defer i.Unlock()
-
-	return i.ipAliases
-}
-
 func (i *nwIface) Routes() []*net.IPNet {
 	i.Lock()
 	defer i.Unlock()
@@ -337,7 +329,6 @@ func configureInterface(nlh *netlink.Handle, iface netlink.Link, i *nwIface) err
 		{setInterfaceIPv6, fmt.Sprintf("error setting interface %q IPv6 to %v", ifaceName, i.AddressIPv6())},
 		{setInterfaceMaster, fmt.Sprintf("error setting interface %q master to %q", ifaceName, i.DstMaster())},
 		{setInterfaceLinkLocalIPs, fmt.Sprintf("error setting interface %q link local IPs to %v", ifaceName, i.LinkLocalAddresses())},
-		{setInterfaceIPAliases, fmt.Sprintf("error setting interface %q IP Aliases to %v", ifaceName, i.IPAliases())},
 	}
 
 	for _, config := range ifaceConfigurators {
@@ -399,16 +390,6 @@ func setInterfaceLinkLocalIPs(nlh *netlink.Handle, iface netlink.Link, i *nwIfac
 	return nil
 }
 
-func setInterfaceIPAliases(nlh *netlink.Handle, iface netlink.Link, i *nwIface) error {
-	for _, si := range i.IPAliases() {
-		ipAddr := &netlink.Addr{IPNet: si}
-		if err := nlh.AddrAdd(iface, ipAddr); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
 func setInterfaceName(nlh *netlink.Handle, iface netlink.Link, i *nwIface) error {
 	return nlh.LinkSetName(iface, i.DstName())
 }

libnetwork/osl/namespace_linux.go

@@ -356,6 +356,22 @@ func (n *networkNamespace) loopbackUp() error {
 	return n.nlHandle.LinkSetUp(iface)
 }
 
+func (n *networkNamespace) AddLoopbackAliasIP(ip *net.IPNet) error {
+	iface, err := n.nlHandle.LinkByName("lo")
+	if err != nil {
+		return err
+	}
+	return n.nlHandle.AddrAdd(iface, &netlink.Addr{IPNet: ip})
+}
+
+func (n *networkNamespace) RemoveLoopbackAliasIP(ip *net.IPNet) error {
+	iface, err := n.nlHandle.LinkByName("lo")
+	if err != nil {
+		return err
+	}
+	return n.nlHandle.AddrDel(iface, &netlink.Addr{IPNet: ip})
+}
+
 func (n *networkNamespace) InvokeFunc(f func()) error {
 	return nsInvoke(n.nsPath(), func(nsFD int) error { return nil }, func(callerFD int) error {
 		f()

libnetwork/osl/options_linux.go

@@ -66,12 +66,6 @@ func (n *networkNamespace) LinkLocalAddresses(list []*net.IPNet) IfaceOption {
 	}
 }
 
-func (n *networkNamespace) IPAliases(list []*net.IPNet) IfaceOption {
-	return func(i *nwIface) {
-		i.ipAliases = list
-	}
-}
-
 func (n *networkNamespace) Routes(routes []*net.IPNet) IfaceOption {
 	return func(i *nwIface) {
 		i.routes = routes

libnetwork/osl/sandbox.go

@@ -32,6 +32,12 @@ type Sandbox interface {
 	// Unset the previously set default IPv6 gateway in the sandbox
 	UnsetGatewayIPv6() error
 
+	// AddLoopbackAliasIP adds the passed IP address to the sandbox loopback interface
+	AddLoopbackAliasIP(ip *net.IPNet) error
+
+	// RemoveLoopbackAliasIP removes the passed IP address from the sandbox loopback interface
+	RemoveLoopbackAliasIP(ip *net.IPNet) error
+
 	// Add a static route to the sandbox.
 	AddStaticRoute(*types.StaticRoute) error
 
@@ -91,9 +97,6 @@ type IfaceOptionSetter interface {
 	// LinkLocalAddresses returns an option setter to set the link-local IP addresses.
 	LinkLocalAddresses([]*net.IPNet) IfaceOption
 
-	// IPAliases returns an option setter to set IP address Aliases
-	IPAliases([]*net.IPNet) IfaceOption
-
 	// Master returns an option setter to set the master interface if any for this
 	// interface. The master interface name should refer to the srcname of a
 	// previously added interface of type bridge.
@@ -150,9 +153,6 @@ type Interface interface {
 	// LinkLocalAddresses returns the link-local IP addresses assigned to the interface.
 	LinkLocalAddresses() []*net.IPNet
 
-	// IPAliases returns the IP address aliases assigned to the interface.
-	IPAliases() []*net.IPNet
-
 	// IP routes for the interface.
 	Routes() []*net.IPNet
 

libnetwork/sandbox.go

@@ -709,8 +709,15 @@ func releaseOSSboxResources(osSbox osl.Sandbox, ep *endpoint) {
 
 	ep.Lock()
 	joinInfo := ep.joinInfo
+	vip := ep.virtualIP
 	ep.Unlock()
 
+	if len(vip) != 0 {
+		if err := osSbox.RemoveLoopbackAliasIP(&net.IPNet{IP: vip, Mask: net.CIDRMask(32, 32)}); err != nil {
+			logrus.Warnf("Remove virtual IP %v failed: %v", vip, err)
+		}
+	}
+
 	if joinInfo == nil {
 		return
 	}
@@ -767,10 +774,6 @@ func (sb *sandbox) restoreOslSandbox() error {
 		if len(i.llAddrs) != 0 {
 			ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().LinkLocalAddresses(i.llAddrs))
 		}
-		if len(ep.virtualIP) != 0 {
-			vipAlias := &net.IPNet{IP: ep.virtualIP, Mask: net.CIDRMask(32, 32)}
-			ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().IPAliases([]*net.IPNet{vipAlias}))
-		}
 		Ifaces[fmt.Sprintf("%s+%s", i.srcName, i.dstPrefix)] = ifaceOptions
 		if joinInfo != nil {
 			routes = append(routes, joinInfo.StaticRoutes...)
@@ -818,10 +821,6 @@ func (sb *sandbox) populateNetworkResources(ep *endpoint) error {
 		if len(i.llAddrs) != 0 {
 			ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().LinkLocalAddresses(i.llAddrs))
 		}
-		if len(ep.virtualIP) != 0 {
-			vipAlias := &net.IPNet{IP: ep.virtualIP, Mask: net.CIDRMask(32, 32)}
-			ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().IPAliases([]*net.IPNet{vipAlias}))
-		}
 		if i.mac != nil {
 			ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().MacAddress(i.mac))
 		}
@@ -831,6 +830,13 @@ func (sb *sandbox) populateNetworkResources(ep *endpoint) error {
 		}
 	}
 
+	if len(ep.virtualIP) != 0 {
+		err := sb.osSbox.AddLoopbackAliasIP(&net.IPNet{IP: ep.virtualIP, Mask: net.CIDRMask(32, 32)})
+		if err != nil {
+			return fmt.Errorf("failed to add virtual IP %v: %v", ep.virtualIP, err)
+		}
+	}
+
 	if joinInfo != nil {
 		// Set up non-interface routes.
 		for _, r := range joinInfo.StaticRoutes {