Handle -version flag on all commands

Tested: Passed -version argument to kubelet (and all other binaries):
  $ output/go/bin/kubecfg -version
  Kubernetes version 0.1, build 6454a541fd56

Signed-off-by: Filipe Brandenburger <filbranden@google.com>

cmd/apiserver/apiserver.go

@@ -29,6 +29,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/master"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/golang/glog"
 )
 
@@ -54,6 +55,8 @@ func main() {
 	util.InitLogs()
 	defer util.FlushLogs()
 
+	version.PrintAndExitIfRequested()
+
 	if len(machineList) == 0 {
 		glog.Fatal("No machines specified!")
 	}

cmd/controller-manager/controller-manager.go

@@ -28,6 +28,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/controller"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/coreos/go-etcd/etcd"
 	"github.com/golang/glog"
 )
@@ -46,6 +47,8 @@ func main() {
 	util.InitLogs()
 	defer util.FlushLogs()
 
+	version.PrintAndExitIfRequested()
+
 	if len(etcdServerList) == 0 || len(*master) == 0 {
 		glog.Fatal("usage: controller-manager -etcd_servers <servers> -master <master>")
 	}

cmd/kubecfg/kubecfg.go

@@ -37,7 +37,6 @@ import (
 )
 
 var (
-	versionFlag   = flag.Bool("V", false, "Print the version number.")
 	serverVersion = flag.Bool("server_version", false, "Print the server's version number.")
 	preventSkew   = flag.Bool("expect_version_match", false, "Fail if server's version doesn't match own version.")
 	httpServer    = flag.String("h", "", "The host to connect to.")
@@ -107,10 +106,7 @@ func main() {
 	util.InitLogs()
 	defer util.FlushLogs()
 
-	if *versionFlag {
+	version.PrintAndExitIfRequested()
-		fmt.Printf("Version: %#v\n", version.Get())
-		os.Exit(0)
-	}
 
 	secure := true
 	var masterServer string

cmd/kubelet/kubelet.go

@@ -35,6 +35,7 @@ import (
 	kconfig "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/config"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/tools"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/coreos/go-etcd/etcd"
 	"github.com/fsouza/go-dockerclient"
 	"github.com/golang/glog"
@@ -95,6 +96,8 @@ func main() {
 	defer util.FlushLogs()
 	rand.Seed(time.Now().UTC().UnixNano())
 
+	version.PrintAndExitIfRequested()
+
 	etcd.SetLogger(util.NewLogger("etcd "))
 
 	dockerClient, err := docker.NewClient(getDockerEndpoint())

cmd/proxy/proxy.go

@@ -22,6 +22,7 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/proxy"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/proxy/config"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/version"
 	"github.com/coreos/go-etcd/etcd"
 	"github.com/golang/glog"
 )
@@ -40,6 +41,8 @@ func main() {
 	util.InitLogs()
 	defer util.FlushLogs()
 
+	version.PrintAndExitIfRequested()
+
 	// Set up logger for etcd client
 	etcd.SetLogger(util.NewLogger("etcd "))
 

hack/test-cmd.sh

@@ -82,7 +82,7 @@ wait_for_url "http://localhost:4001/version" "etcd: "
 
 
 # Check kubecfg
-out=$(${GO_OUT}/kubecfg -V)
+out=$(${GO_OUT}/kubecfg -version)
 echo kubecfg: $out
 
 # Start kubelet

pkg/version/version.go

@@ -16,6 +16,16 @@ limitations under the License.
 
 package version
 
+import (
+	"flag"
+	"fmt"
+	"os"
+)
+
+var (
+	versionFlag = flag.Bool("version", false, "Print version information and quit")
+)
+
 // Info contains versioning information.
 // TODO: Add []string of api versions supported? It's still unclear
 // how we'll want to distribute that information.
@@ -34,3 +44,17 @@ func Get() Info {
 		GitCommit: commitFromGit,
 	}
 }
+
+// String returns info as a human-friendly version string.
+func (info Info) String() string {
+	return fmt.Sprintf("version %s.%s, build %s", info.Major, info.Minor, info.GitCommit)
+}
+
+// PrintAndExitIfRequested will check if the -version flag was passed
+// and, if so, print the version and exit.
+func PrintAndExitIfRequested() {
+	if *versionFlag {
+		fmt.Printf("Kubernetes %s\n", Get())
+		os.Exit(0)
+	}
+}