Add integration test.

Signed-off-by: Lantao Liu <lantaol@google.com>

pkg/server/sandbox_status.go

@@ -99,8 +99,9 @@ func toCRISandboxStatus(meta sandboxstore.Metadata, status sandboxstore.Status,
 	}
 }
 
+// SandboxInfo is extra information for sandbox.
 // TODO (mikebrow): discuss predefining constants structures for some or all of these field names in CRI
-type sandboxInfo struct {
+type SandboxInfo struct {
 	Pid            uint32                    `json:"pid"`
 	Status         string                    `json:"processStatus"`
 	NetNSClosed    bool                      `json:"netNamespaceClosed"`
@@ -132,7 +133,7 @@ func toCRISandboxInfo(ctx context.Context, sandbox sandboxstore.Sandbox) (map[st
 		processStatus = taskStatus.Status
 	}
 
-	si := &sandboxInfo{
+	si := &SandboxInfo{
 		Pid:            sandbox.Status.Get().Pid,
 		RuntimeHandler: sandbox.RuntimeHandler,
 		Status:         string(processStatus),