Add container and pod namespaces to configs

Libpod namespaces are a way to logically separate groups of pods
and containers within the state.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

libpod/container.go

@@ -185,6 +185,8 @@ type ContainerConfig struct {
 	Name string     `json:"name"`
 	// Full ID of the pood the container belongs to
 	Pod string `json:"pod,omitempty"`
+	// Namespace the container is in
+	Namespace string `json:"namespace,omitempty"`
 
 	// TODO consider breaking these subsections up into smaller structs
 
@@ -372,6 +374,12 @@ func (c *Container) PodID() string {
 	return c.config.Pod
 }
 
+// Namespace returns the libpod namespace the container is in.
+// Namespaces are used to logically separate containers and pods in the state.
+func (c *Container) Namespace() string {
+	return c.config.Namespace
+}
+
 // Image returns the ID and name of the image used as the container's rootfs
 func (c *Container) Image() (string, string) {
 	return c.config.RootfsImageID, c.config.RootfsImageName