Add --version argument to commands

.gitattributes

@@ -0,0 +1 @@
+/pkg/types/version.go export-subst

Makefile

@@ -1,4 +1,5 @@
 TAG ?= $(shell git describe --match=NeVeRmAtCh --always --abbrev=40 --dirty)
+GIT_VERSION ?= $(shell git describe --always --dirty)
 CONTAINER_RUNTIME ?= podman
 
 .PHONY: build
@@ -7,7 +8,8 @@ build: gvproxy qemu-wrapper vm
 TOOLS_DIR := tools
 include tools/tools.mk
 
-LDFLAGS = -s -w
+VERSION_LDFLAGS=-X github.com/containers/gvisor-tap-vsock/pkg/types.gitVersion=$(GIT_VERSION)
+LDFLAGS = -s -w $(VERSION_LDFLAGS)
 
 .PHONY: gvproxy
 gvproxy:

cmd/gvproxy/main.go

@@ -56,6 +56,8 @@ const (
 )
 
 func main() {
+	version := types.NewVersion("gvproxy")
+	version.AddFlag()
 	flag.Var(&endpoints, "listen", "control endpoint")
 	flag.BoolVar(&debug, "debug", false, "Print debug info")
 	flag.IntVar(&mtu, "mtu", 1500, "Set the MTU")
@@ -72,6 +74,12 @@ func main() {
 	flag.StringVar(&pidFile, "pid-file", "", "Generate a file with the PID in it")
 	flag.Parse()
 
+	if version.ShowVersion() {
+		fmt.Println(version.String())
+		os.Exit(0)
+	}
+
+	log.Infof(version.String())
 	ctx, cancel := context.WithCancel(context.Background())
 	// Make this the last defer statement in the stack
 	defer os.Exit(exitCode)

cmd/ssh-over-vsock/main.go

@@ -4,8 +4,10 @@ import (
 	"flag"
 	"fmt"
 	"net"
+	"os"
 
 	"github.com/containers/gvisor-tap-vsock/pkg/transport"
+	"github.com/containers/gvisor-tap-vsock/pkg/types"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 )
@@ -19,13 +21,20 @@ var (
 )
 
 func main() {
+	version := types.NewVersion("ssh-over-vsock")
+	version.AddFlag()
 	flag.StringVar(&ip, "ip", "192.168.127.2", "ip of the host")
 	flag.IntVar(&port, "port", 22, "port of the host")
 	flag.StringVar(&user, "user", "", "ssh user")
 	flag.StringVar(&key, "key", "", "ssh key")
 	flag.StringVar(&endpoint, "url", "/tmp/network.sock", "url of the daemon")
 	flag.Parse()
 
+	if version.ShowVersion() {
+		fmt.Println(version.String())
+		os.Exit(0)
+	}
+
 	if err := run(); err != nil {
 		logrus.Fatal(err)
 	}

cmd/vm/main_linux.go

@@ -35,6 +35,8 @@ var (
 )
 
 func main() {
+	version := types.NewVersion("gvforwarder")
+	version.AddFlag()
 	flag.StringVar(&endpoint, "url", fmt.Sprintf("vsock://2:1024%s", types.ConnectPath), "url where the tap send packets")
 	flag.StringVar(&iface, "iface", "tap0", "tap interface name")
 	flag.StringVar(&stopIfIfaceExist, "stop-if-exist", "eth0,ens3,enp0s1", "stop if one of these interfaces exists at startup")
@@ -44,6 +46,11 @@ func main() {
 	flag.BoolVar(&tapPreexists, "preexisting", false, "use preexisting/preconfigured TAP interface")
 	flag.Parse()
 
+	if version.ShowVersion() {
+		fmt.Println(version.String())
+		os.Exit(0)
+	}
+
 	expected := strings.Split(stopIfIfaceExist, ",")
 	links, err := netlink.LinkList()
 	if err != nil {

cmd/win-sshproxy/main.go

@@ -14,6 +14,7 @@ import (
 	"unsafe"
 
 	"github.com/containers/gvisor-tap-vsock/pkg/sshclient"
+	"github.com/containers/gvisor-tap-vsock/pkg/types"
 	"github.com/containers/winquit/pkg/winquit"
 	"github.com/sirupsen/logrus"
 	"golang.org/x/sync/errgroup"
@@ -33,10 +34,15 @@ var (
 func main() {
 	args := os.Args
 	if len(args) > 1 {
-		if args[1] == "-debug" {
+		switch args[1] {
+		case "-version":
+			version := types.NewVersion("win-sshproxy")
+			fmt.Println(version.String())
+			os.Exit(0)
+		case "-debug":
 			debug = true
 			args = args[2:]
-		} else {
+		default:
 			args = args[1:]
 		}
 	}

pkg/types/version.go

@@ -0,0 +1,64 @@
+package types
+
+import (
+	"flag"
+	"fmt"
+	"runtime/debug"
+	"strings"
+)
+
+var (
+	// set using the '-X github.com/containers/gvisor-tap-vsock/pkg/types.gitVersion' linker flag
+	gitVersion = ""
+	// set through .gitattributes when `git archive` is used
+	// see https://icinga.com/blog/2022/05/25/embedding-git-commit-information-in-go-binaries/
+	gitArchiveVersion = "$Format:%(describe)$"
+)
+
+type version struct {
+	binaryName  string
+	showVersion bool
+}
+
+func NewVersion(binaryName string) *version { //nolint:revive
+	return &version{
+		binaryName: binaryName,
+	}
+}
+
+func (ver *version) String() string {
+	return fmt.Sprintf("%s version %s", ver.binaryName, moduleVersion())
+}
+
+func (ver *version) AddFlag() {
+	flag.BoolVar(&ver.showVersion, "version", false, "Print version information")
+}
+
+func (ver *version) ShowVersion() bool {
+	return ver.showVersion
+}
+
+func moduleVersion() string {
+	switch {
+	// This will be substituted when building from a GitHub tarball
+	case !strings.HasPrefix(gitArchiveVersion, "$Format:"):
+		return gitArchiveVersion
+	// This will be set when building from git using make
+	case gitVersion != "":
+		return gitVersion
+	// moduleVersionFromBuildInfo() will be set when using `go install`
+	default:
+		return moduleVersionFromBuildInfo()
+	}
+}
+
+func moduleVersionFromBuildInfo() string {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		return ""
+	}
+	if info.Main.Version == "(devel)" {
+		return ""
+	}
+	return info.Main.Version
+}