Add version output to CLIs

This change adds version output to the nvidia-continer-runtime,
nvidia-container-toolkit, and nvidia-ctk CLIs. The same version
is used in all cases and includes a version string and a git
revision if set.

The construction of the version string mirrors what is done in runc.

Signed-off-by: Evan Lezar <elezar@nvidia.com>

cmd/nvidia-container-runtime/main.go

@@ -3,11 +3,19 @@ package main
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/NVIDIA/nvidia-container-toolkit/internal/config"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/info"
+	"github.com/opencontainers/runtime-spec/specs-go"
 )
 
-var Version string
+// version must be set by go build's -X main.version= option in the Makefile.
+var version = "unknown"
+
+// gitCommit will be the hash that the binary was built from
+// and will be populated by the Makefile
+var gitCommit = ""
 
 var logger = NewLogger()
 
@@ -22,6 +30,11 @@ func main() {
 // run is an entry point that allows for idiomatic handling of errors
 // when calling from the main function.
 func run(argv []string) (rerr error) {
+	printVersion := hasVersionFlag(argv)
+	if printVersion {
+		fmt.Printf("%v version %v\n", "NVIDIA Container Runtime", info.GetVersionString(fmt.Sprintf("spec: %v", specs.Version)))
+	}
+
 	cfg, err := config.GetConfig()
 	if err != nil {
 		return fmt.Errorf("error loading config: %v", err)
@@ -43,5 +56,29 @@ func run(argv []string) (rerr error) {
 		return fmt.Errorf("failed to create NVIDIA Container Runtime: %v", err)
 	}
 
+	if printVersion {
+		fmt.Print("\n")
+	}
 	return runtime.Exec(argv)
 }
+
+// TODO: This should be refactored / combined with parseArgs in logger.
+func hasVersionFlag(args []string) bool {
+	for i := 0; i < len(args); i++ {
+		param := args[i]
+
+		parts := strings.SplitN(param, "=", 2)
+		trimmed := strings.TrimLeft(parts[0], "-")
+		// If this is not a flag we continue
+		if parts[0] == trimmed {
+			continue
+		}
+
+		// Check the version flag
+		if trimmed == "version" {
+			return true
+		}
+	}
+
+	return false
+}

cmd/nvidia-container-toolkit/main.go

@@ -18,8 +18,9 @@ import (
 )
 
 var (
-	debugflag  = flag.Bool("debug", false, "enable debug output")
-	configflag = flag.String("config", "", "configuration file")
+	debugflag   = flag.Bool("debug", false, "enable debug output")
+	versionflag = flag.Bool("version", false, "enable version output")
+	configflag  = flag.String("config", "", "configuration file")
 )
 
 func exit() {
@@ -159,6 +160,11 @@ func main() {
 	flag.Usage = usage
 	flag.Parse()
 
+	if *versionflag {
+		fmt.Printf("%v version %v\n", "NVIDIA Container Runtime Hook", info.GetVersionString())
+		return
+	}
+
 	args := flag.Args()
 	if len(args) == 0 {
 		flag.Usage()

cmd/nvidia-ctk/main.go

@@ -20,12 +20,11 @@ import (
 	"os"
 
 	"github.com/NVIDIA/nvidia-container-toolkit/cmd/nvidia-ctk/hook"
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/info"
 	log "github.com/sirupsen/logrus"
 	cli "github.com/urfave/cli/v2"
 )
 
-var version string
-
 var logger = log.New()
 
 // config defines the options that can be set for the CLI through config files,
@@ -41,10 +40,11 @@ func main() {
 
 	// Create the top-level CLI
 	c := cli.NewApp()
+	c.Name = "NVIDIA Container Toolkit CLI"
 	c.UseShortOptionHandling = true
 	c.EnableBashCompletion = true
 	c.Usage = "Tools to configure the NVIDIA Container Toolkit"
-	c.Version = version
+	c.Version = info.GetVersionString()
 
 	// Setup the flags for this command
 	c.Flags = []cli.Flag{

internal/info/version.go

@@ -0,0 +1,43 @@
+/**
+# Copyright (c) 2022, NVIDIA CORPORATION.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+**/
+
+package info
+
+import "strings"
+
+// version must be set by go build's -X main.version= option in the Makefile.
+var version = "unknown"
+
+// gitCommit will be the hash that the binary was built from
+// and will be populated by the Makefile
+var gitCommit = ""
+
+// GetVersionParts returns the different version components
+func GetVersionParts() []string {
+	v := []string{version}
+
+	if gitCommit != "" {
+		v = append(v, "commit: "+gitCommit)
+	}
+
+	return v
+}
+
+// GetVersionString returns the string representation of the version
+func GetVersionString(more ...string) string {
+	v := append(GetVersionParts(), more...)
+	return strings.Join(v, "\n")
+}