Add version subcommand

Makefile

@@ -14,11 +14,14 @@
 
 IMAGE=amazon/aws-ebs-csi-driver
 VERSION=0.1.0-alpha
+GIT_COMMIT?=$(shell git rev-parse HEAD)
+BUILD_DATE?=$(shell date -u +"%Y-%m-%dT%H:%M:%SZ")
+LDFLAGS?="-X github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver.driverVersion=${VERSION} -X github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver.gitCommit=${GIT_COMMIT} -X github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver.buildDate=${BUILD_DATE}"
 
 .PHONY: aws-ebs-csi-driver
 aws-ebs-csi-driver:
 	mkdir -p bin
-	CGO_ENABLED=0 GOOS=linux go build -ldflags "-X github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver.vendorVersion=${VERSION}" -o bin/aws-ebs-csi-driver ./cmd/
+	CGO_ENABLED=0 GOOS=linux go build -ldflags ${LDFLAGS} -o bin/aws-ebs-csi-driver ./cmd/
 
 .PHONY: test
 test:

cmd/main.go

@@ -18,16 +18,30 @@ package main
 
 import (
 	"flag"
+	"fmt"
+	"os"
 
 	"github.com/golang/glog"
 	"github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/cloud"
 	"github.com/kubernetes-sigs/aws-ebs-csi-driver/pkg/driver"
 )
 
 func main() {
-	var endpoint = flag.String("endpoint", "unix://tmp/csi.sock", "CSI Endpoint")
+	var (
+		endpoint = flag.String("endpoint", "unix://tmp/csi.sock", "CSI Endpoint")
+		version  = flag.Bool("version", false, "Print the version and exit.")
+	)
 	flag.Parse()
 
+	if *version {
+		info, err := driver.GetVersionJSON()
+		if err != nil {
+			glog.Fatalln(err)
+		}
+		fmt.Println(info)
+		os.Exit(0)
+	}
+
 	cloud, err := cloud.NewCloud()
 	if err != nil {
 		glog.Fatalln(err)

pkg/driver/driver.go

@@ -33,11 +33,6 @@ const (
 	topologyKey = "topology." + driverName + "/zone"
 )
 
-var (
-	// vendorVersion is the version driver and is set during build
-	vendorVersion string
-)
-
 type Driver struct {
 	endpoint string
 	nodeID   string

pkg/driver/identity.go

@@ -27,7 +27,7 @@ func (d *Driver) GetPluginInfo(ctx context.Context, req *csi.GetPluginInfoReques
 	glog.V(4).Infof("GetPluginInfo: called with args %+v", *req)
 	resp := &csi.GetPluginInfoResponse{
 		Name:          driverName,
-		VendorVersion: vendorVersion,
+		VendorVersion: driverVersion,
 	}
 
 	return resp, nil

pkg/driver/version.go

@@ -0,0 +1,43 @@
+package driver
+
+import (
+	"encoding/json"
+	"fmt"
+	"runtime"
+)
+
+// These are set during build time via -ldflags
+var (
+	driverVersion string
+	gitCommit     string
+	buildDate     string
+)
+
+type VersionInfo struct {
+	DriverVersion string `json:"driverVersion"`
+	GitCommit     string `json:"gitCommit"`
+	BuildDate     string `json:"buildDate"`
+	GoVersion     string `json:"goVersion"`
+	Compiler      string `json:"compiler"`
+	Platform      string `json:"platform"`
+}
+
+func GetVersion() VersionInfo {
+	return VersionInfo{
+		DriverVersion: driverVersion,
+		GitCommit:     gitCommit,
+		BuildDate:     buildDate,
+		GoVersion:     runtime.Version(),
+		Compiler:      runtime.Compiler,
+		Platform:      fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
+	}
+}
+
+func GetVersionJSON() (string, error) {
+	info := GetVersion()
+	marshalled, err := json.MarshalIndent(&info, "", "  ")
+	if err != nil {
+		return "", err
+	}
+	return string(marshalled), nil
+}