Add HostNetworking container option to API.

This allows a container to run within the same networking namespace as
the host. This will be locked down by default using a flag on the master
and nodes (similar to how privileged is handled today).

pkg/api/v1beta3/defaults.go

@@ -67,6 +67,9 @@ func init() {
 			if obj.RestartPolicy == "" {
 				obj.RestartPolicy = RestartPolicyAlways
 			}
+			if obj.HostNetwork {
+				defaultHostNetworkPorts(&obj.Containers)
+			}
 		},
 		func(obj *Probe) {
 			if obj.TimeoutSeconds == 0 {
@@ -101,3 +104,14 @@ func init() {
 		},
 	)
 }
+
+// With host networking default all container ports to host ports.
+func defaultHostNetworkPorts(containers *[]Container) {
+	for i := range *containers {
+		for j := range (*containers)[i].Ports {
+			if (*containers)[i].Ports[j].HostPort == 0 {
+				(*containers)[i].Ports[j].HostPort = (*containers)[i].Ports[j].ContainerPort
+			}
+		}
+	}
+}

pkg/api/v1beta3/defaults_test.go

@@ -97,3 +97,29 @@ func TestSetDefaultNamespace(t *testing.T) {
 		t.Errorf("Expected phase %v, got %v", current.NamespaceActive, s2.Status.Phase)
 	}
 }
+
+func TestSetDefaultPodSpecHostNetwork(t *testing.T) {
+	portNum := 8080
+	s := current.PodSpec{}
+	s.HostNetwork = true
+	s.Containers = []current.Container{
+		{
+			Ports: []current.ContainerPort{
+				{
+					ContainerPort: portNum,
+				},
+			},
+		},
+	}
+	pod := &current.Pod{
+		Spec: s,
+	}
+	obj2 := roundTrip(t, runtime.Object(pod))
+	pod2 := obj2.(*current.Pod)
+	s2 := pod2.Spec
+
+	hostPortNum := s2.Containers[0].Ports[0].HostPort
+	if hostPortNum != portNum {
+		t.Errorf("Expected container port to be defaulted, was made %d instead of %d", hostPortNum, portNum)
+	}
+}

pkg/api/v1beta3/types.go

@@ -298,6 +298,7 @@ type ContainerPort struct {
 	// in a pod must have a unique name.
 	Name string `json:"name,omitempty" description:"name for the port that can be referred to by services; must be a DNS_LABEL and unique without the pod"`
 	// Optional: If specified, this must be a valid port number, 0 < x < 65536.
+	// If HostNetwork is specified, this must match ContainerPort.
 	HostPort int `json:"hostPort,omitempty" description:"number of port to expose on the host; most containers do not need this"`
 	// Required: This must be a valid port number, 0 < x < 65536.
 	ContainerPort int `json:"containerPort" description:"number of port to expose on the pod's IP address"`
@@ -586,6 +587,10 @@ type PodSpec struct {
 	// the the scheduler simply schedules this pod onto that host, assuming that it fits
 	// resource requirements.
 	Host string `json:"host,omitempty" description:"host requested for this pod"`
+	// Uses the host's network namespace. If this option is set, the ports that will be
+	// used must be specified.
+	// Optional: Default to false.
+	HostNetwork bool `json:"hostNetwork,omitempty" description:"host networking requested for this pod"`
 }
 
 // PodStatus represents information about the status of a pod. Status may trail the actual