add version sub command

Signed-off-by: Jeff <zw0948@gmail.com>

pkg/version/version.go

@@ -17,6 +17,7 @@ limitations under the License.
 package version
 
 import (
+	"encoding/json"
 	"fmt"
 	"runtime"
 
@@ -45,14 +46,20 @@ type Info struct {
 	Kubernetes   *apimachineryversion.Info `json:"kubernetes,omitempty"`
 }
 
+func (info Info) String() string {
+	jsonString, _ := json.Marshal(info)
+	return string(jsonString)
+}
+
 // Get returns the overall codebase version. It's for
 // detecting what code a binary was built from.
 func Get() Info {
 	// These variables typically come from -ldflags settings and
 	// in their absence fallback to the default settings
 	return Info{
-		GitVersion: gitVersion,
-
+		GitVersion:   gitVersion,
+		GitMajor:     gitMajor,
+		GitMinor:     gitMinor,
 		GitCommit:    gitCommit,
 		GitTreeState: gitTreeState,
 		BuildDate:    buildDate,