Adding --version / -V support to print version information (#312)

* Alphabetize options.options.KubeRouterConfig

* Add --version / -V support to kube-router

Fixes #287

Author: SEJeff

Makefile

@@ -1,5 +1,6 @@
 NAME?=kube-router
 DEV_SUFFIX?=-git
+BUILD_DATE?=$(shell date --iso-8601)
 LOCAL_PACKAGES?=app app/controllers app/options app/watchers utils
 IMG_NAMESPACE?=cloudnativelabs
 GIT_COMMIT=$(shell git describe --tags --dirty)
@@ -18,7 +19,7 @@ all: test kube-router container ## Default target. Runs tests, builds binaries a
 
 kube-router:
 	@echo Starting kube-router binary build.
-	CGO_ENABLED=0 go build -o kube-router kube-router.go
+	CGO_ENABLED=0 go build -ldflags '-X github.com/cloudnativelabs/kube-router/app.version=$(GIT_COMMIT) -X github.com/cloudnativelabs/kube-router/app.buildDate=$(BUILD_DATE)' -o kube-router kube-router.go
 	@echo Finished kube-router binary build.
 
 test: gofmt ## Runs code quality pipelines (gofmt, tests, coverage, lint, etc)

app/options/options.go

@@ -8,40 +8,41 @@ import (
 )
 
 type KubeRouterConfig struct {
-	HelpRequested       bool
-	Kubeconfig          string
-	Master              string
-	ConfigSyncPeriod    time.Duration
-	CleanupConfig       bool
-	IPTablesSyncPeriod  time.Duration
-	IpvsSyncPeriod      time.Duration
-	RoutesSyncPeriod    time.Duration
-	RunServiceProxy     bool
-	RunFirewall         bool
-	RunRouter           bool
-	MasqueradeAll       bool
-	ClusterCIDR         string
-	EnablePodEgress     bool
-	HostnameOverride    string
 	AdvertiseClusterIp  bool
 	AdvertiseExternalIp bool
-	PeerRouters         []net.IP
-	PeerASNs            []uint
-	PeerMultihopTtl     uint8
-	ClusterAsn          uint
-	FullMeshMode        bool
 	BGPGracefulRestart  bool
+	CleanupConfig       bool
+	ClusterAsn          uint
+	ClusterCIDR         string
+	ConfigSyncPeriod    time.Duration
 	EnableiBGP          bool
-	GlobalHairpinMode   bool
-	NodePortBindOnAllIp bool
 	EnableOverlay       bool
-	PeerPasswords       []string
+	EnablePodEgress     bool
 	EnablePprof         bool
+	FullMeshMode        bool
+	GlobalHairpinMode   bool
+	HealthPort          uint16
+	HelpRequested       bool
+	HostnameOverride    string
+	IPTablesSyncPeriod  time.Duration
+	IpvsSyncPeriod      time.Duration
+	Kubeconfig          string
+	MasqueradeAll       bool
+	Master              string
 	MetricsEnabled      bool
-	MetricsPort         uint16
 	MetricsPath         string
+	MetricsPort         uint16
+	NodePortBindOnAllIp bool
+	PeerASNs            []uint
+	PeerMultihopTtl     uint8
+	PeerPasswords       []string
+	PeerRouters         []net.IP
+	RoutesSyncPeriod    time.Duration
+	RunFirewall         bool
+	RunRouter           bool
+	RunServiceProxy     bool
+	Version             bool
 	VLevel              string
-	HealthPort          uint16
 	// FullMeshPassword    string
 }
 
@@ -57,6 +58,8 @@ func NewKubeRouterConfig() *KubeRouterConfig {
 func (s *KubeRouterConfig) AddFlags(fs *pflag.FlagSet) {
 	fs.BoolVarP(&s.HelpRequested, "help", "h", false,
 		"Print usage information.")
+	fs.BoolVarP(&s.Version, "version", "V", false,
+		"Print version information.")
 	fs.BoolVar(&s.RunServiceProxy, "run-service-proxy", true,
 		"Enables Service Proxy -- sets up IPVS for Kubernetes Services.")
 	fs.BoolVar(&s.RunFirewall, "run-firewall", true,
@@ -120,5 +123,4 @@ func (s *KubeRouterConfig) AddFlags(fs *pflag.FlagSet) {
 	// 	"Password that cluster-node BGP servers will use to authenticate one another when \"--nodes-full-mesh\" is set.")
 	fs.StringVarP(&s.VLevel, "v", "v", "0", "log level for V logs")
 	fs.Uint16Var(&s.HealthPort, "health-port", 20244, "Health check port, 0 = Disabled")
-
 }

app/server.go

@@ -2,8 +2,10 @@ package app
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"os/signal"
+	"runtime"
 	"sync"
 	"syscall"
 
@@ -16,6 +18,10 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 )
 
+// These get set at build time via -ldflags magic
+var version string
+var buildDate string
+
 // KubeRouter holds the information needed to run server
 type KubeRouter struct {
 	Client *kubernetes.Clientset
@@ -27,6 +33,7 @@ func NewKubeRouterDefault(config *options.KubeRouterConfig) (*KubeRouter, error)
 
 	var clientconfig *rest.Config
 	var err error
+	PrintVersion(true)
 	// Use out of cluster config if the URL or kubeconfig have been specified. Otherwise use incluster config.
 	if len(config.Master) != 0 || len(config.Kubeconfig) != 0 {
 		clientconfig, err = clientcmd.BuildConfigFromFlags(config.Master, config.Kubeconfig)
@@ -193,3 +200,13 @@ func (kr *KubeRouter) Run() error {
 	wg.Wait()
 	return nil
 }
+
+func PrintVersion(logOutput bool) {
+	output := fmt.Sprintf("Running %v version %s, built on %s, %s\n", os.Args[0], version, buildDate, runtime.Version())
+
+	if !logOutput {
+		fmt.Fprintf(os.Stderr, output)
+	} else {
+		glog.Info(output)
+	}
+}

kube-router.go

@@ -31,6 +31,11 @@ func main() {
 		os.Exit(0)
 	}
 
+	if config.Version {
+		app.PrintVersion(false)
+		os.Exit(0)
+	}
+
 	if os.Geteuid() != 0 {
 		fmt.Fprintf(os.Stderr, "kube-router needs to be run with privileges to execute iptables, ipset and configure ipvs\n")
 		os.Exit(1)