sandbox: store endpoint in cri sandboxStore

Signed-off-by: Abel Feng <fshb1988@gmail.com>

internal/cri/store/sandbox/sandbox.go

@@ -47,6 +47,18 @@ type Sandbox struct {
 	*store.StopCh
 	// Stats contains (mutable) stats for the (pause) sandbox container
 	Stats *stats.ContainerStats
+	// Endpoint is the sandbox endpoint, for task or streaming api connection
+	Endpoint Endpoint
+}
+
+type Endpoint struct {
+	Address  string
+	Protocol string
+	Version  uint32
+}
+
+func (e *Endpoint) IsValid() bool {
+	return e.Protocol != "" && e.Address != ""
 }
 
 // NewSandbox creates an internally used sandbox type. This functions reminds