[no-relnote] Add app struct for nvidia-toolkit

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

tools/container/nvidia-toolkit/run.go

@@ -8,10 +8,10 @@ import (
 	"strings"
 	"syscall"
 
-	log "github.com/sirupsen/logrus"
 	"github.com/urfave/cli/v2"
 	"golang.org/x/sys/unix"
 
+	"github.com/NVIDIA/nvidia-container-toolkit/internal/logger"
 	"github.com/NVIDIA/nvidia-container-toolkit/tools/container/runtime"
 	"github.com/NVIDIA/nvidia-container-toolkit/tools/container/toolkit"
 )
@@ -51,12 +51,44 @@ func (o options) toolkitRoot() string {
 var Version = "development"
 
 func main() {
-	remainingArgs, root, err := ParseArgs(os.Args)
+	logger := logger.New()
+
+	remainingArgs, root, err := ParseArgs(logger, os.Args)
 	if err != nil {
-		log.Errorf("Error: unable to parse arguments: %v", err)
+		logger.Errorf("Error: unable to parse arguments: %v", err)
 		os.Exit(1)
 	}
 
+	c := NewApp(logger, root)
+
+	// Run the CLI
+	logger.Infof("Starting %v", c.Name)
+	if err := c.Run(remainingArgs); err != nil {
+		logger.Errorf("error running nvidia-toolkit: %v", err)
+		os.Exit(1)
+	}
+
+	logger.Infof("Completed %v", c.Name)
+}
+
+// An app represents the nvidia-ctk-installer.
+type app struct {
+	logger logger.Interface
+	// defaultRoot stores the root to use if the --root flag is not specified.
+	defaultRoot string
+}
+
+// NewApp creates the CLI app fro the specified options.
+// defaultRoot is used as the root if not specified via the --root flag.
+func NewApp(logger logger.Interface, defaultRoot string) *cli.App {
+	a := app{
+		logger:      logger,
+		defaultRoot: defaultRoot,
+	}
+	return a.build()
+}
+
+func (a app) build() *cli.App {
 	options := options{
 		toolkitOptions: toolkit.Options{},
 	}
@@ -68,10 +100,10 @@ func main() {
 	c.Description = "DESTINATION points to the host path underneath which the nvidia-container-toolkit should be installed.\nIt will be installed at ${DESTINATION}/toolkit"
 	c.Version = Version
 	c.Before = func(ctx *cli.Context) error {
-		return validateFlags(ctx, &options)
+		return a.Before(ctx, &options)
 	}
 	c.Action = func(ctx *cli.Context) error {
-		return Run(ctx, &options)
+		return a.Run(ctx, &options)
 	}
 
 	// Setup flags for the CLI
@@ -102,7 +134,7 @@ func main() {
 		},
 		&cli.StringFlag{
 			Name:        "root",
-			Value:       root,
+			Value:       a.defaultRoot,
 			Usage:       "the folder where the NVIDIA Container Toolkit is to be installed. It will be installed to `ROOT`/toolkit",
 			Destination: &options.root,
 			EnvVars:     []string{"ROOT"},
@@ -119,17 +151,14 @@ func main() {
 	c.Flags = append(c.Flags, toolkit.Flags(&options.toolkitOptions)...)
 	c.Flags = append(c.Flags, runtime.Flags(&options.runtimeOptions)...)
 
-	// Run the CLI
+	return c
-	log.Infof("Starting %v", c.Name)
-	if err := c.Run(remainingArgs); err != nil {
-		log.Errorf("error running nvidia-toolkit: %v", err)
-		os.Exit(1)
-	}
-
-	log.Infof("Completed %v", c.Name)
 }
 
-func validateFlags(_ *cli.Context, o *options) error {
+func (a *app) Before(c *cli.Context, o *options) error {
+	return a.validateFlags(c, o)
+}
+
+func (a *app) validateFlags(_ *cli.Context, o *options) error {
 	if o.root == "" {
 		return fmt.Errorf("the install root must be specified")
 	}
@@ -139,6 +168,7 @@ func validateFlags(_ *cli.Context, o *options) error {
 	if filepath.Base(o.pidFile) != toolkitPidFilename {
 		return fmt.Errorf("invalid toolkit.pid path %v", o.pidFile)
 	}
+
 	if err := toolkit.ValidateOptions(&o.toolkitOptions, o.toolkitRoot()); err != nil {
 		return err
 	}
@@ -149,12 +179,12 @@ func validateFlags(_ *cli.Context, o *options) error {
 }
 
 // Run runs the core logic of the CLI
-func Run(c *cli.Context, o *options) error {
+func (a *app) Run(c *cli.Context, o *options) error {
-	err := initialize(o.pidFile)
+	err := a.initialize(o.pidFile)
 	if err != nil {
 		return fmt.Errorf("unable to initialize: %v", err)
 	}
-	defer shutdown(o.pidFile)
+	defer a.shutdown(o.pidFile)
 
 	if len(o.toolkitOptions.ContainerRuntimeRuntimes.Value()) == 0 {
 		lowlevelRuntimePaths, err := runtime.GetLowlevelRuntimePaths(&o.runtimeOptions, o.runtime)
@@ -176,7 +206,7 @@ func Run(c *cli.Context, o *options) error {
 	}
 
 	if !o.noDaemon {
-		err = waitForSignal()
+		err = a.waitForSignal()
 		if err != nil {
 			return fmt.Errorf("unable to wait for signal: %v", err)
 		}
@@ -192,8 +222,8 @@ func Run(c *cli.Context, o *options) error {
 
 // ParseArgs checks if a single positional argument was defined and extracts this the root.
 // If no positional arguments are defined, it is assumed that the root is specified as a flag.
-func ParseArgs(args []string) ([]string, string, error) {
+func ParseArgs(logger logger.Interface, args []string) ([]string, string, error) {
-	log.Infof("Parsing arguments")
+	logger.Infof("Parsing arguments")
 
 	if len(args) < 2 {
 		return args, "", nil
@@ -218,8 +248,8 @@ func ParseArgs(args []string) ([]string, string, error) {
 	return nil, "", fmt.Errorf("unexpected positional argument(s) %v", args[2:lastPositionalArg+1])
 }
 
-func initialize(pidFile string) error {
+func (a *app) initialize(pidFile string) error {
-	log.Infof("Initializing")
+	a.logger.Infof("Initializing")
 
 	if dir := filepath.Dir(pidFile); dir != "" {
 		err := os.MkdirAll(dir, 0755)
@@ -235,8 +265,8 @@ func initialize(pidFile string) error {
 
 	err = unix.Flock(int(f.Fd()), unix.LOCK_EX|unix.LOCK_NB)
 	if err != nil {
-		log.Warningf("Unable to get exclusive lock on '%v'", pidFile)
+		a.logger.Warningf("Unable to get exclusive lock on '%v'", pidFile)
-		log.Warningf("This normally means an instance of the NVIDIA toolkit Container is already running, aborting")
+		a.logger.Warningf("This normally means an instance of the NVIDIA toolkit Container is already running, aborting")
 		return fmt.Errorf("unable to get flock on pidfile: %v", err)
 	}
 
@@ -253,8 +283,8 @@ func initialize(pidFile string) error {
 		case <-waitingForSignal:
 			signalReceived <- true
 		default:
-			log.Infof("Signal received, exiting early")
+			a.logger.Infof("Signal received, exiting early")
-			shutdown(pidFile)
+			a.shutdown(pidFile)
 			os.Exit(0)
 		}
 	}()
@@ -262,18 +292,18 @@ func initialize(pidFile string) error {
 	return nil
 }
 
-func waitForSignal() error {
+func (a *app) waitForSignal() error {
-	log.Infof("Waiting for signal")
+	a.logger.Infof("Waiting for signal")
 	waitingForSignal <- true
 	<-signalReceived
 	return nil
 }
 
-func shutdown(pidFile string) {
+func (a *app) shutdown(pidFile string) {
-	log.Infof("Shutting Down")
+	a.logger.Infof("Shutting Down")
 
 	err := os.Remove(pidFile)
 	if err != nil {
-		log.Warningf("Unable to remove pidfile: %v", err)
+		a.logger.Warningf("Unable to remove pidfile: %v", err)
 	}
 }