From d170b0ca802b2ea7d18dc682d3376d19fa072e13 Mon Sep 17 00:00:00 2001
From: yiqinguo <468894985@qq.com>
Date: Thu, 22 Jun 2017 20:17:28 +0800
Subject: [PATCH] Add type conversion judgment

---
 pkg/kubelet/dockershim/docker_service.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pkg/kubelet/dockershim/docker_service.go b/pkg/kubelet/dockershim/docker_service.go
index 59cebc405fe..6a8a5b97e11 100644
--- a/pkg/kubelet/dockershim/docker_service.go
+++ b/pkg/kubelet/dockershim/docker_service.go
@@ -455,10 +455,13 @@ func (ds *dockerService) getDockerVersionFromCache() (*dockertypes.Version, erro
 	// We only store on key in the cache.
 	const dummyKey = "version"
 	value, err := ds.versionCache.Get(dummyKey)
-	dv := value.(*dockertypes.Version)
 	if err != nil {
 		return nil, err
 	}
+	dv, ok := value.(*dockertypes.Version)
+	if !ok {
+		return nil, fmt.Errorf("Converted to *dockertype.Version error")
+	}
 	return dv, nil
 }