Refactor overlayDir to container.RunDir()

Signed-off-by: Jonathon Anderson <[email protected]>

internal/app/wwctl/container/exec/child/main.go

@@ -21,8 +21,6 @@ import (
 	"github.com/warewulf/warewulf/internal/pkg/wwlog"
 )
 
-const exitEval = `$(VALU="$?" ; if [ $VALU == 0 ]; then echo create new image; else echo no new image; fi)`
-
 func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	if os.Getpid() != 1 {
 		wwlog.Error("PID is not 1: %d", os.Getpid())
@@ -36,33 +34,39 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 		os.Exit(1)
 	}
 	conf := warewulfconf.Get()
-	if overlayDir == "" {
-		overlayDir = path.Join(conf.Paths.WWChrootdir, "overlays")
+	runDir := container.RunDir(containerName)
+	if _, err := os.Stat(runDir); os.IsNotExist(err) {
+		return errors.Wrap(err, "container run directory does not exist")
 	}
 	mountPts := conf.MountsContainer
 	mountPts = append(container.InitMountPnts(binds), mountPts...)
 	// check for valid mount points
 	lowerObjects := checkMountPoints(containerName, mountPts)
 	// need to create a overlay, where the lower layer contains
 	// the missing mount points
-	wwlog.Verbose("for ephermal mount use tempdir %s", overlayDir)
-	// ignore errors as we are doomed if a tmp dir couldn't be written
-	_ = os.MkdirAll(path.Join(overlayDir, "work"), os.ModePerm)
-	_ = os.MkdirAll(path.Join(overlayDir, "lower"), os.ModePerm)
-	_ = os.MkdirAll(path.Join(overlayDir, "nodeoverlay"), os.ModePerm)
+	wwlog.Verbose("for ephermal mount use tempdir %s", runDir)
+	if err = os.Mkdir(path.Join(runDir, "work"), os.ModePerm); err != nil {
+		return err
+	}
+	if err = os.Mkdir(path.Join(runDir, "lower"), os.ModePerm); err != nil {
+		return err
+	}
+	if err = os.Mkdir(path.Join(runDir, "nodeoverlay"), os.ModePerm); err != nil {
+		return err
+	}
 	// handle all lower object, have some extra logic if the object is a file
 	for _, obj := range lowerObjects {
 		newFile := ""
 		if !strings.HasSuffix(obj, "/") {
 			newFile = filepath.Base(obj)
 			obj = filepath.Dir(obj)
 		}
-		err = os.MkdirAll(filepath.Join(overlayDir, "lower", obj), os.ModePerm)
+		err = os.Mkdir(filepath.Join(runDir, "lower", obj), os.ModePerm)
 		if err != nil {
 			wwlog.Warn("couldn't create directory for mounts: %s", err)
 		}
 		if newFile != "" {
-			desc, err := os.Create(filepath.Join(overlayDir, "lower", obj, newFile))
+			desc, err := os.Create(filepath.Join(runDir, "lower", obj, newFile))
 			if err != nil {
 				wwlog.Warn("couldn't create directory for mounts: %s", err)
 			}
@@ -75,10 +79,10 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	if err != nil {
 		return errors.Wrap(err, "failed to mount")
 	}
-	ps1Str := fmt.Sprintf("[%s|%s] Warewulf> ", exitEval, containerName)
+	ps1Str := fmt.Sprintf("[%s] Warewulf> ", containerName)
 	if len(lowerObjects) != 0 && nodename == "" {
 		options := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s",
-			path.Join(overlayDir, "lower"), containerPath, path.Join(overlayDir, "work"))
+			path.Join(runDir, "lower"), containerPath, path.Join(runDir, "work"))
 		wwlog.Debug("overlay options: %s", options)
 		err = syscall.Mount("overlay", containerPath, "overlay", 0, options)
 		if err != nil {
@@ -103,13 +107,13 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 		}
 		overlays := nodes[0].SystemOverlay.GetSlice()
 		overlays = append(overlays, nodes[0].RuntimeOverlay.GetSlice()...)
-		err = overlay.BuildOverlayIndir(nodes[0], overlays, path.Join(overlayDir, "nodeoverlay"))
+		err = overlay.BuildOverlayIndir(nodes[0], overlays, path.Join(runDir, "nodeoverlay"))
 		if err != nil {
 			wwlog.Error("Could not build overlay: %s", err)
 			os.Exit(1)
 		}
 		options := fmt.Sprintf("lowerdir=%s:%s:%s",
-			path.Join(overlayDir, "lower"), containerPath, path.Join(overlayDir, "nodeoverlay"))
+			path.Join(runDir, "lower"), containerPath, path.Join(runDir, "nodeoverlay"))
 		wwlog.Debug("overlay options: %s", options)
 		err = syscall.Mount("overlay", containerPath, "overlay", 0, options)
 		if err != nil {
@@ -171,11 +175,8 @@ func CobraRunE(cmd *cobra.Command, args []string) (err error) {
 	os.Setenv("PATH", "/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin")
 	os.Setenv("HISTFILE", "/dev/null")
 
-	_ = syscall.Exec(args[1], args[1:], os.Environ())
-	/*
-		Exec replaces the actual program, so nothing to do here afterwards
-	*/
-	return nil
+	wwlog.Debug("Exec: %s %s", args[1], args[1:])
+	return syscall.Exec(args[1], args[1:], os.Environ())
 }
 
 /*

internal/app/wwctl/container/exec/child/root.go

@@ -13,16 +13,13 @@ var (
 		Args:                  cobra.MinimumNArgs(1),
 		FParseErrWhitelist:    cobra.FParseErrWhitelist{UnknownFlags: true},
 	}
-	binds      []string
-	nodename   string
-	overlayDir string
+	binds    []string
+	nodename string
 )
 
 func init() {
 	baseCmd.Flags().StringVarP(&nodename, "node", "n", "", "create ro overlay for given node")
 	baseCmd.Flags().StringArrayVarP(&binds, "bind", "b", []string{}, "bind points")
-	baseCmd.Flags().StringVar(&overlayDir, "overlaydir", "", "overlayDir")
-
 }
 
 // GetRootCommand returns the root cobra.Command for the application.

internal/app/wwctl/container/exec/main.go

@@ -9,7 +9,6 @@ import (
 	"os"
 	"os/exec"
 	"path"
-	"path/filepath"
 	"syscall"
 	"time"
 
@@ -26,20 +25,23 @@ fork off a process with a new PID space
 */
 func runContainedCmd(args []string) (err error) {
 	conf := warewulfconf.Get()
-	if matches, _ := filepath.Glob(path.Join(conf.Paths.WWChrootdir, args[0], args[0]) + "-run-*"); len(matches) > 0 {
-		return fmt.Errorf("found lock directories for container: %v", matches)
-	}
-	overlayDir, err = os.MkdirTemp(path.Join(conf.Paths.WWChrootdir, args[0]), args[0]+"-run-")
-	if err != nil {
-		wwlog.Warn("couldn't create temp dir for overlay", err)
+	containerName := args[0]
+	runDir := container.RunDir(containerName)
+	if err := os.Mkdir(runDir, 0750); err != nil {
+		if _, existerr := os.Stat(runDir); !os.IsNotExist(existerr) {
+			return errors.New("run directory already exists: another container command may already be running")
+		} else {
+			return fmt.Errorf("unable to create run directory: %w", err)
+		}
 	}
 	defer func() {
-		err = errors.Join(os.RemoveAll(overlayDir), err)
+		if err := errors.Join(os.RemoveAll(runDir), err); err != nil {
+			wwlog.Error("error removing run directory: %w", err)
+		}
 	}()
-
 	logStr := fmt.Sprint(wwlog.GetLogLevel())
 	wwlog.Verbose("Running contained command: %s", args[1:])
-	c := exec.Command("/proc/self/exe", append([]string{"--warewulfconf", conf.GetWarewulfConf(), "--loglevel", logStr, "--overlaydir", overlayDir, "container", "exec", "__child"}, args...)...)
+	c := exec.Command("/proc/self/exe", append([]string{"--warewulfconf", conf.GetWarewulfConf(), "--loglevel", logStr, "container", "exec", "__child"}, args...)...)
 
 	c.SysProcAttr = &syscall.SysProcAttr{
 		Cloneflags: syscall.CLONE_NEWUTS | syscall.CLONE_NEWPID | syscall.CLONE_NEWNS,

internal/app/wwctl/container/exec/root.go

@@ -25,17 +25,15 @@ var (
 		},
 		FParseErrWhitelist: cobra.FParseErrWhitelist{UnknownFlags: true},
 	}
-	SyncUser   bool
-	binds      []string
-	overlayDir string
-	nodeName   string
+	SyncUser bool
+	binds    []string
+	nodeName string
 )
 
 func init() {
 	baseCmd.AddCommand(child.GetCommand())
 	baseCmd.PersistentFlags().StringArrayVarP(&binds, "bind", "b", []string{}, "Bind a local path into the container (must exist)")
 	baseCmd.PersistentFlags().BoolVar(&SyncUser, "syncuser", false, "Synchronize UIDs/GIDs from host to container")
-	baseCmd.PersistentFlags().StringVar(&overlayDir, "overlaydir", "", "Use tempdir for constructing the overlay fs (only used if mount points don't exist in container)")
 	baseCmd.PersistentFlags().StringVarP(&nodeName, "node", "n", "", "Create a read only view of the container for the given node")
 }
 

internal/pkg/container/config.go

@@ -33,6 +33,10 @@ func RootFsDir(name string) string {
 	return path.Join(SourceDir(name), "rootfs")
 }
 
+func RunDir(name string) string {
+	return path.Join(SourceDir(name), "run")
+}
+
 func ImageParentDir() string {
 	conf := warewulfconf.Get()
 	return path.Join(conf.Paths.WWProvisiondir, "container/")