add version api (#2127)

add cluster validation api

pkg/version/version.go

@@ -16,4 +16,43 @@ limitations under the License.
 
 package version
 
-var Version = "v0.0.0"
+import (
+	"fmt"
+	"runtime"
+
+	apimachineryversion "k8s.io/apimachinery/pkg/version"
+)
+
+var (
+	version      = "v0.0.0"
+	gitCommit    = "unknown"
+	gitTreeState = "unknown"
+	buildDate    = "unknown"
+)
+
+type Info struct {
+	Version      string                    `json:"gitVersion"`
+	GitCommit    string                    `json:"gitCommit"`
+	GitTreeState string                    `json:"gitTreeState"`
+	BuildDate    string                    `json:"buildDate"`
+	GoVersion    string                    `json:"goVersion"`
+	Compiler     string                    `json:"compiler"`
+	Platform     string                    `json:"platform"`
+	Kubernetes   *apimachineryversion.Info `json:"kubernetes,omitempty"`
+}
+
+// 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{
+		Version:      version,
+		GitCommit:    gitCommit,
+		GitTreeState: gitTreeState,
+		BuildDate:    buildDate,
+		GoVersion:    runtime.Version(),
+		Compiler:     runtime.Compiler,
+		Platform:     fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
+	}
+}