fix -version option: print version (#367)

What this PR does / why we need it:
this is a bug fix. if we using following command

$ ./tf_operator -version
it will not print any version information.

Which issue(s) this PR fixes (optional, in fixes #(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
NONE

Special notes for your reviewer:
NONE @jlewi

Release note:

NONE

cmd/tf_operator/app/server.go

@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"runtime"
 	"time"
 
 	"github.com/ghodss/yaml"
@@ -56,12 +55,12 @@ func Run(opt *options.ServerOption) error {
 		namespace = metav1.NamespaceDefault
 	}
 
-	glog.Infof("tf_operator Version: %v", version.Version)
-	glog.Infof("Git SHA: %s", version.GitSHA)
-	glog.Infof("Go Version: %s", runtime.Version())
-	glog.Infof("Go OS/Arch: %s/%s", runtime.GOOS, runtime.GOARCH)
+	// To help debugging, immediately log version
+	glog.Infof("%+v", version.Info())
+
+	// Check if the -version flag was passed and, if so, print the version and exit.
 	if opt.PrintVersion {
-		os.Exit(0)
+		version.PrintVersionAndExit()
 	}
 
 	config, err := k8sutil.GetClusterConfig()

version/version.go

@@ -13,24 +13,28 @@
 package version
 
 import (
-	"os"
+	"fmt"
 	"runtime"
-
-	log "github.com/golang/glog"
+	"os"
 )
 
 var (
 	Version = "0.3.0+git"
 	GitSHA  = "Not provided."
 )
 
-// PrintVersion print version info
-func PrintVersion(shouldExit bool) {
-	log.Infof("tf_operator Version: %v", Version)
-	log.Infof("Git SHA: %s", GitSHA)
-	log.Infof("Go Version: %s", runtime.Version())
-	log.Infof("Go OS/Arch: %s/%s", runtime.GOOS, runtime.GOARCH)
-	if shouldExit {
-		os.Exit(0)
+func PrintVersionAndExit(){
+	for _, i := range Info(){
+		fmt.Printf("%v\n", i)
+	}
+	os.Exit(0)
+}
+
+func Info() []string{
+	return []string{
+		fmt.Sprintf("Version: %v", Version),
+		fmt.Sprintf("Git SHA: %s", GitSHA),
+		fmt.Sprintf("Go Version: %s", runtime.Version()),
+		fmt.Sprintf("Go OS/Arch: %s/%s", runtime.GOOS, runtime.GOARCH),
 	}
 }