Improve load balancing scalability in swarm mode

controller.go

@@ -871,7 +871,7 @@ addToStore:
 		}
 	}()
 
-	if len(network.loadBalancerIP) != 0 {
+	if network.hasLoadBalancerEndpoint() {
 		if err = network.createLoadBalancerSandbox(); err != nil {
 			return nil, err
 		}

default_gateway.go

@@ -49,9 +49,11 @@ func (sb *sandbox) setupDefaultGW() error {
 
 	createOptions := []EndpointOption{CreateOptionAnonymous()}
 
-	eplen := gwEPlen
-	if len(sb.containerID) < gwEPlen {
-		eplen = len(sb.containerID)
+	var gwName string
+	if len(sb.containerID) <= gwEPlen {
+		gwName = "gateway_" + sb.containerID
+	} else {
+		gwName = "gateway_" + sb.id[:gwEPlen]
 	}
 
 	sbLabels := sb.Labels()
@@ -69,7 +71,7 @@ func (sb *sandbox) setupDefaultGW() error {
 		createOptions = append(createOptions, epOption)
 	}
 
-	newEp, err := n.CreateEndpoint("gateway_"+sb.containerID[0:eplen], createOptions...)
+	newEp, err := n.CreateEndpoint(gwName, createOptions...)
 	if err != nil {
 		return fmt.Errorf("container %s: endpoint create on GW Network failed: %v", sb.containerID, err)
 	}

endpoint.go

@@ -540,6 +540,12 @@ func (ep *endpoint) sbJoin(sb *sandbox, options ...EndpointOption) (err error) {
 		}
 	}()
 
+	// Load balancing endpoints should never have a default gateway nor
+	// should they alter the status of a network's default gateway
+	if ep.loadBalancer && !sb.ingress {
+		return nil
+	}
+
 	if sb.needDefaultGW() && sb.getEndpointInGWNetwork() == nil {
 		return sb.setupDefaultGW()
 	}

endpoint_info.go

@@ -49,6 +49,9 @@ type InterfaceInfo interface {
 
 	// LinkLocalAddresses returns the list of link-local (IPv4/IPv6) addresses assigned to the endpoint.
 	LinkLocalAddresses() []*net.IPNet
+
+	// SrcName returns the name of the interface w/in the container
+	SrcName() string
 }
 
 type endpointInterface struct {
@@ -272,6 +275,10 @@ func (epi *endpointInterface) LinkLocalAddresses() []*net.IPNet {
 	return epi.llAddrs
 }
 
+func (epi *endpointInterface) SrcName() string {
+	return epi.srcName
+}
+
 func (epi *endpointInterface) SetNames(srcName string, dstPrefix string) error {
 	epi.srcName = srcName
 	epi.dstPrefix = dstPrefix

network.go

@@ -40,7 +40,7 @@ type Network interface {
 	CreateEndpoint(name string, options ...EndpointOption) (Endpoint, error)
 
 	// Delete the network.
-	Delete() error
+	Delete(options ...NetworkDeleteOption) error
 
 	// Endpoints returns the list of Endpoint(s) in this network.
 	Endpoints() []Endpoint
@@ -875,6 +875,28 @@ func (n *network) processOptions(options ...NetworkOption) {
 	}
 }
 
+type networkDeleteParams struct {
+	rmLBEndpoint bool
+}
+
+// NetworkDeleteOption is a type for optional parameters to pass to the
+// network.Delete() function.
+type NetworkDeleteOption func(p *networkDeleteParams)
+
+// NetworkDeleteOptionRemoveLB informs a network.Delete() operation that should
+// remove the load balancer endpoint for this network.  Note that the Delete()
+// method will automatically remove a load balancing endpoint for most networks
+// when the network is otherwise empty.  However, this does not occur for some
+// networks.  In particular, networks marked as ingress (which are supposed to
+// be more permanent than other overlay networks) won't automatically remove
+// the LB endpoint on Delete().  This method allows for explicit removal of
+// such networks provided there are no other endpoints present in the network.
+// If the network still has non-LB endpoints present, Delete() will not
+// remove the LB endpoint and will return an error.
+func NetworkDeleteOptionRemoveLB(p *networkDeleteParams) {
+	p.rmLBEndpoint = true
+}
+
 func (n *network) resolveDriver(name string, load bool) (driverapi.Driver, *driverapi.Capability, error) {
 	c := n.getController()
 
@@ -938,11 +960,23 @@ func (n *network) driver(load bool) (driverapi.Driver, error) {
 	return d, nil
 }
 
-func (n *network) Delete() error {
-	return n.delete(false)
+func (n *network) Delete(options ...NetworkDeleteOption) error {
+	var params networkDeleteParams
+	for _, opt := range options {
+		opt(&params)
+	}
+	return n.delete(false, params.rmLBEndpoint)
 }
 
-func (n *network) delete(force bool) error {
+// This function gets called in 3 ways:
+//  * Delete() -- (false, false)
+//      remove if endpoint count == 0 or endpoint count == 1 and
+//      there is a load balancer IP
+//  * Delete(libnetwork.NetworkDeleteOptionRemoveLB) -- (false, true)
+//      remove load balancer and network if endpoint count == 1
+//  * controller.networkCleanup() -- (true, true)
+//      remove the network no matter what
+func (n *network) delete(force bool, rmLBEndpoint bool) error {
 	n.Lock()
 	c := n.ctrlr
 	name := n.name
@@ -957,10 +991,32 @@ func (n *network) delete(force bool) error {
 		return &UnknownNetworkError{name: name, id: id}
 	}
 
-	if len(n.loadBalancerIP) != 0 {
-		endpoints := n.Endpoints()
-		if force || (len(endpoints) == 1 && !n.ingress) {
-			n.deleteLoadBalancerSandbox()
+	// Only remove ingress on force removal or explicit LB endpoint removal
+	if n.ingress && !force && !rmLBEndpoint {
+		return &ActiveEndpointsError{name: n.name, id: n.id}
+	}
+
+	// Check that the network is empty
+	var emptyCount uint64
+	if n.hasLoadBalancerEndpoint() {
+		emptyCount = 1
+	}
+	if !force && n.getEpCnt().EndpointCnt() > emptyCount {
+		if n.configOnly {
+			return types.ForbiddenErrorf("configuration network %q is in use", n.Name())
+		}
+		return &ActiveEndpointsError{name: n.name, id: n.id}
+	}
+
+	if n.hasLoadBalancerEndpoint() {
+		// If we got to this point, then the following must hold:
+		//  * force is true OR endpoint count == 1
+		if err := n.deleteLoadBalancerSandbox(); err != nil {
+			if !force {
+				return err
+			}
+			// continue deletion when force is true even on error
+			logrus.Warnf("Error deleting load balancer sandbox: %v", err)
 		}
 		//Reload the network from the store to update the epcnt.
 		n, err = c.getNetworkFromStore(id)
@@ -969,12 +1025,10 @@ func (n *network) delete(force bool) error {
 		}
 	}
 
-	if !force && n.getEpCnt().EndpointCnt() != 0 {
-		if n.configOnly {
-			return types.ForbiddenErrorf("configuration network %q is in use", n.Name())
-		}
-		return &ActiveEndpointsError{name: n.name, id: n.id}
-	}
+	// Up to this point, errors that we returned were recoverable.
+	// From here on, any errors leave us in an inconsistent state.
+	// This is unfortunate, but there isn't a safe way to
+	// reconstitute a load-balancer endpoint after removing it.
 
 	// Mark the network for deletion
 	n.inDelete = true
@@ -1023,9 +1077,6 @@ func (n *network) delete(force bool) error {
 	// Cleanup the service discovery for this network
 	c.cleanupServiceDiscovery(n.ID())
 
-	// Cleanup the load balancer
-	c.cleanupServiceBindings(n.ID())
-
 removeFromStore:
 	// deleteFromStore performs an atomic delete operation and the
 	// network.epCnt will help prevent any possible
@@ -1877,6 +1928,10 @@ func (n *network) hasSpecialDriver() bool {
 	return n.Type() == "host" || n.Type() == "null"
 }
 
+func (n *network) hasLoadBalancerEndpoint() bool {
+	return len(n.loadBalancerIP) != 0
+}
+
 func (n *network) ResolveName(req string, ipType int) ([]net.IP, bool) {
 	var ipv6Miss bool
 
@@ -2056,8 +2111,20 @@ func (c *controller) getConfigNetwork(name string) (*network, error) {
 	return n.(*network), nil
 }
 
-func (n *network) createLoadBalancerSandbox() error {
-	sandboxName := n.name + "-sbox"
+func (n *network) lbSandboxName() string {
+	name := "lb-" + n.name
+	if n.ingress {
+		name = n.name + "-sbox"
+	}
+	return name
+}
+
+func (n *network) lbEndpointName() string {
+	return n.name + "-endpoint"
+}
+
+func (n *network) createLoadBalancerSandbox() (retErr error) {
+	sandboxName := n.lbSandboxName()
 	sbOptions := []SandboxOption{}
 	if n.ingress {
 		sbOptions = append(sbOptions, OptionIngress())
@@ -2067,44 +2134,49 @@ func (n *network) createLoadBalancerSandbox() error {
 		return err
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			if e := n.ctrlr.SandboxDestroy(sandboxName); e != nil {
-				logrus.Warnf("could not delete sandbox %s on failure on failure (%v): %v", sandboxName, err, e)
+				logrus.Warnf("could not delete sandbox %s on failure on failure (%v): %v", sandboxName, retErr, e)
 			}
 		}
 	}()
 
-	endpointName := n.name + "-endpoint"
+	endpointName := n.lbEndpointName()
 	epOptions := []EndpointOption{
 		CreateOptionIpam(n.loadBalancerIP, nil, nil, nil),
 		CreateOptionLoadBalancer(),
 	}
+	if n.hasLoadBalancerEndpoint() && !n.ingress {
+		// Mark LB endpoints as anonymous so they don't show up in DNS
+		epOptions = append(epOptions, CreateOptionAnonymous())
+	}
 	ep, err := n.createEndpoint(endpointName, epOptions...)
 	if err != nil {
 		return err
 	}
 	defer func() {
-		if err != nil {
+		if retErr != nil {
 			if e := ep.Delete(true); e != nil {
-				logrus.Warnf("could not delete endpoint %s on failure on failure (%v): %v", endpointName, err, e)
+				logrus.Warnf("could not delete endpoint %s on failure on failure (%v): %v", endpointName, retErr, e)
 			}
 		}
 	}()
 
 	if err := ep.Join(sb, nil); err != nil {
 		return err
 	}
+
 	return sb.EnableService()
 }
 
-func (n *network) deleteLoadBalancerSandbox() {
+func (n *network) deleteLoadBalancerSandbox() error {
 	n.Lock()
 	c := n.ctrlr
 	name := n.name
 	n.Unlock()
 
-	endpointName := name + "-endpoint"
-	sandboxName := name + "-sbox"
+	sandboxName := n.lbSandboxName()
+	endpointName := n.lbEndpointName()
 
 	endpoint, err := n.EndpointByName(endpointName)
 	if err != nil {
@@ -2129,6 +2201,7 @@ func (n *network) deleteLoadBalancerSandbox() {
 	}
 
 	if err := c.SandboxDestroy(sandboxName); err != nil {
-		logrus.Warnf("Failed to delete %s sandbox: %v", sandboxName, err)
+		return fmt.Errorf("Failed to delete %s sandbox: %v", sandboxName, err)
 	}
+	return nil
 }

osl/namespace_linux.go

@@ -358,16 +358,20 @@ func (n *networkNamespace) loopbackUp() error {
 	return n.nlHandle.LinkSetUp(iface)
 }
 
-func (n *networkNamespace) AddLoopbackAliasIP(ip *net.IPNet) error {
-	iface, err := n.nlHandle.LinkByName("lo")
+func (n *networkNamespace) GetLoopbackIfaceName() string {
+	return "lo"
+}
+
+func (n *networkNamespace) AddAliasIP(ifName string, ip *net.IPNet) error {
+	iface, err := n.nlHandle.LinkByName(ifName)
 	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")
+func (n *networkNamespace) RemoveAliasIP(ifName string, ip *net.IPNet) error {
+	iface, err := n.nlHandle.LinkByName(ifName)
 	if err != nil {
 		return err
 	}

osl/sandbox.go

@@ -32,11 +32,14 @@ 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
+	// GetLoopbackIfaceName returns the name of the loopback interface
+	GetLoopbackIfaceName() string
 
-	// RemoveLoopbackAliasIP removes the passed IP address from the sandbox loopback interface
-	RemoveLoopbackAliasIP(ip *net.IPNet) error
+	// AddAliasIP adds the passed IP address to the named interface
+	AddAliasIP(ifName string, ip *net.IPNet) error
+
+	// RemoveAliasIP removes the passed IP address from the named interface
+	RemoveAliasIP(ifName string, ip *net.IPNet) error
 
 	// Add a static route to the sandbox.
 	AddStaticRoute(*types.StaticRoute) error

sandbox.go

@@ -740,15 +740,8 @@ 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
 	}
@@ -861,13 +854,6 @@ 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 {
@@ -893,7 +879,7 @@ func (sb *sandbox) populateNetworkResources(ep *endpoint) error {
 	// information including gateway and other routes so that
 	// loadbalancers are populated all the network state is in
 	// place in the sandbox.
-	sb.populateLoadbalancers(ep)
+	sb.populateLoadBalancers(ep)
 
 	// Only update the store if we did not come here as part of
 	// sandbox delete. If we came here as part of delete then do