Expose ingress network option

Signed-off-by: Alessandro Boch <aboch@docker.com>

libnetwork/controller.go

@@ -682,6 +682,10 @@ func (c *controller) NewNetwork(networkType, name string, id string, options ...
 		return nil, err
 	}
 
+	if network.ingress && cap.DataScope != datastore.GlobalScope {
+		return nil, types.ForbiddenErrorf("Ingress network can only be global scope network")
+	}
+
 	if cap.DataScope == datastore.GlobalScope && !c.isDistributedControl() && !network.dynamic {
 		if c.isManager() {
 			// For non-distributed controlled environment, globalscoped non-dynamic networks are redirected to Manager
@@ -1161,15 +1165,29 @@ func (c *controller) clearIngress(clusterLeave bool) {
 	c.ingressSandbox = nil
 	c.Unlock()
 
+	var n *network
 	if ingressSandbox != nil {
+		for _, ep := range ingressSandbox.getConnectedEndpoints() {
+			if nw := ep.getNetwork(); nw.ingress {
+				n = nw
+				break
+			}
+		}
 		if err := ingressSandbox.Delete(); err != nil {
 			logrus.Warnf("Could not delete ingress sandbox while leaving: %v", err)
 		}
 	}
 
-	n, err := c.NetworkByName("ingress")
-	if err != nil && clusterLeave {
-		logrus.Warnf("Could not find ingress network while leaving: %v", err)
+	if n == nil {
+		for _, nw := range c.Networks() {
+			if nw.Info().Ingress() {
+				n = nw.(*network)
+				break
+			}
+		}
+	}
+	if n == nil && clusterLeave {
+		logrus.Warnf("Could not find ingress network while leaving")
 	}
 
 	if n != nil {

libnetwork/network.go

@@ -66,6 +66,7 @@ type NetworkInfo interface {
 	IPv6Enabled() bool
 	Internal() bool
 	Attachable() bool
+	Ingress() bool
 	Labels() map[string]string
 	Dynamic() bool
 	Created() time.Time
@@ -607,9 +608,9 @@ func NetworkOptionGeneric(generic map[string]interface{}) NetworkOption {
 
 // NetworkOptionIngress returns an option setter to indicate if a network is
 // an ingress network.
-func NetworkOptionIngress() NetworkOption {
+func NetworkOptionIngress(ingress bool) NetworkOption {
 	return func(n *network) {
-		n.ingress = true
+		n.ingress = ingress
 	}
 }
 
@@ -1581,6 +1582,13 @@ func (n *network) Attachable() bool {
 	return n.attachable
 }
 
+func (n *network) Ingress() bool {
+	n.Lock()
+	defer n.Unlock()
+
+	return n.ingress
+}
+
 func (n *network) Dynamic() bool {
 	n.Lock()
 	defer n.Unlock()