Rename "container" to "image"

- Updated `wwctl upgrade` to handle updates
- Maintained `.Container` and `.ContainerName` in tstruct
- Added `ContainerName()` methods to node and profile objects
- Added `--container`, `-C` aliases to wwctl commands (`<node|profile> <add|set>`)
- Added `wwctl container` alias
- Added support for `container_exit.sh` if `image_exit.sh` is not found

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

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

@@ -0,0 +1,210 @@
+//go:build linux
+// +build linux
+
+package child
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/spf13/cobra"
+	warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
+	"github.com/warewulf/warewulf/internal/pkg/image"
+	"github.com/warewulf/warewulf/internal/pkg/node"
+	"github.com/warewulf/warewulf/internal/pkg/overlay"
+	"github.com/warewulf/warewulf/internal/pkg/util"
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+)
+
+const exitEval = `$(VALU="$?" ; if [ $VALU == 0 ]; then echo write; else echo discard; fi)`
+
+func CobraRunE(cmd *cobra.Command, args []string) (err error) {
+	if os.Getpid() != 1 {
+		return fmt.Errorf("PID is not 1: %d", os.Getpid())
+	}
+
+	imageName := args[0]
+
+	if !image.ValidSource(imageName) {
+		return fmt.Errorf("unknown Warewulf image: %s", imageName)
+	}
+	conf := warewulfconf.Get()
+	runDir := image.RunDir(imageName)
+	if _, err := os.Stat(runDir); os.IsNotExist(err) {
+		return fmt.Errorf("image run directory does not exist: %w", err)
+	}
+	mountPts := conf.MountsImage
+	mountPts = append(image.InitMountPnts(binds), mountPts...)
+	// check for valid mount points
+	lowerObjects := checkMountPoints(imageName, mountPts)
+	// need to create a overlay, where the lower layer contains
+	// the missing mount points
+	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.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(runDir, "lower", obj, newFile))
+			if err != nil {
+				wwlog.Warn("couldn't create directory for mounts: %s", err)
+			}
+			defer desc.Close()
+		}
+	}
+	imagePath := image.RootFsDir(imageName)
+	// running in a private PID space, so also make / private, so that nothing gets out from here
+	err = syscall.Mount("", "/", "", syscall.MS_PRIVATE|syscall.MS_REC, "")
+	if err != nil {
+		return fmt.Errorf("failed to mount: %w", err)
+	}
+	ps1Str := fmt.Sprintf("[%s|%s] Warewulf> ", imageName, exitEval)
+	if len(lowerObjects) != 0 && nodename == "" {
+		options := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s",
+			path.Join(runDir, "lower"), imagePath, path.Join(runDir, "work"))
+		wwlog.Debug("overlay options: %s", options)
+		err = syscall.Mount("overlay", imagePath, "overlay", 0, options)
+		if err != nil {
+			wwlog.Warn("Couldn't create overlay for ephermal mount points: %s", err)
+		}
+	} else if nodename != "" {
+		nodeDB, err := node.New()
+		if err != nil {
+			return fmt.Errorf("could not open node configuration: %s", err)
+		}
+
+		allNodes, err := nodeDB.FindAllNodes()
+		if err != nil {
+			return fmt.Errorf("could not get node list: %s", err)
+		}
+		filteredNodes := node.FilterNodeListByName(allNodes, []string{nodename})
+		if len(filteredNodes) != 1 {
+			return fmt.Errorf("no single node idendified with %s", nodename)
+		}
+		overlays := filteredNodes[0].SystemOverlay
+		overlays = append(overlays, filteredNodes[0].RuntimeOverlay...)
+		err = overlay.BuildOverlayIndir(filteredNodes[0], allNodes, overlays, path.Join(runDir, "nodeoverlay"))
+		if err != nil {
+			return fmt.Errorf("could not build overlay: %s", err)
+		}
+		options := fmt.Sprintf("lowerdir=%s:%s:%s",
+			path.Join(runDir, "lower"), imagePath, path.Join(runDir, "nodeoverlay"))
+		wwlog.Debug("overlay options: %s", options)
+		err = syscall.Mount("overlay", imagePath, "overlay", 0, options)
+		if err != nil {
+			return fmt.Errorf("Couldn't create overlay for node render overlay: %s", err)
+		}
+		ps1Str = fmt.Sprintf("[%s|ro|%s] Warewulf> ", imageName, nodename)
+	}
+	if !image.IsWriteAble(imageName) && nodename == "" {
+		wwlog.Verbose("mounting %s ro", imagePath)
+		ps1Str = fmt.Sprintf("[%s|ro] Warewulf> ", imageName)
+		err = syscall.Mount(imagePath, imagePath, "", syscall.MS_BIND, "")
+		if err != nil {
+			return fmt.Errorf("failed to prepare bind mount: %w", err)
+		}
+		err = syscall.Mount(imagePath, imagePath, "", syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_BIND, "")
+		if err != nil {
+			return fmt.Errorf("failed to remount ro: %w", err)
+		}
+	}
+
+	for _, mntPnt := range mountPts {
+		if mntPnt.Copy() {
+			continue
+		}
+		wwlog.Debug("bind mounting: %s -> %s", mntPnt.Source, path.Join(imagePath, mntPnt.Dest))
+		err = syscall.Mount(mntPnt.Source, path.Join(imagePath, mntPnt.Dest), "", syscall.MS_BIND, "")
+		if err != nil {
+			wwlog.Warn("Couldn't mount %s to %s: %s", mntPnt.Source, mntPnt.Dest, err)
+		} else if mntPnt.ReadOnly() {
+			err = syscall.Mount(mntPnt.Source, path.Join(imagePath, mntPnt.Dest), "", syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_BIND, "")
+			if err != nil {
+				wwlog.Warn("failed to following mount readonly: %s", mntPnt.Source)
+			} else {
+				wwlog.Verbose("mounted readonly from host to image: %s:%s", mntPnt.Source, mntPnt.Dest)
+			}
+		} else {
+			wwlog.Verbose("mounted from host to image: %s:%s", mntPnt.Source, mntPnt.Dest)
+		}
+	}
+
+	err = syscall.Chroot(imagePath)
+	if err != nil {
+		return fmt.Errorf("failed to chroot: %w", err)
+	}
+
+	err = os.Chdir("/")
+	if err != nil {
+		return fmt.Errorf("failed to chdir: %w", err)
+	}
+
+	if err := syscall.Mount("devtmpfs", "/dev", "devtmpfs", 0, ""); err != nil {
+		return fmt.Errorf("failed to mount /dev: %w", err)
+	}
+	if err := syscall.Mount("sysfs", "/sys", "sysfs", 0, ""); err != nil {
+		return fmt.Errorf("failed to mount /sys: %w", err)
+	}
+	if err := syscall.Mount("proc", "/proc", "proc", 0, ""); err != nil {
+		return fmt.Errorf("failed to mount /proc: %w", err)
+	}
+	if err := syscall.Mount("tmpfs", "/run", "tmpfs", 0, ""); err != nil {
+		return fmt.Errorf("failed to mount /run: %w", err)
+	}
+
+	os.Setenv("PS1", ps1Str)
+	os.Setenv("PATH", "/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin")
+	os.Setenv("HISTFILE", "/dev/null")
+
+	wwlog.Debug("Exec: %s %s", args[1], args[1:])
+	return syscall.Exec(args[1], args[1:], os.Environ())
+}
+
+/*
+Check if the bind mount points exists in the given image. Returns
+the invalid mount points. Directories always have '/' as suffix
+*/
+func checkMountPoints(imageName string, binds []*warewulfconf.MountEntry) (overlayObjects []string) {
+	overlayObjects = []string{}
+	for _, b := range binds {
+		if b.Copy() {
+			continue
+		}
+		_, err := os.Stat(b.Source)
+		if err != nil {
+			wwlog.Debug("Couldn't stat %s create no mount point in image", b.Source)
+			continue
+		}
+		wwlog.Debug("Checking in image for %s", path.Join(image.RootFsDir(imageName), b.Dest))
+		if _, err = os.Stat(path.Join(image.RootFsDir(imageName), b.Dest)); err != nil {
+			if os.IsNotExist(err) {
+				if util.IsDir(b.Dest) && !strings.HasSuffix(b.Dest, "/") {
+					b.Dest += "/"
+				}
+				overlayObjects = append(overlayObjects, b.Dest)
+				wwlog.Debug("Image %s, needs following path: %s", imageName, b.Dest)
+			}
+		}
+	}
+	return overlayObjects
+}

internal/app/wwctl/image/exec/child/non-Linux.go

@@ -0,0 +1,15 @@
+//go:build !linux
+// +build !linux
+
+package child
+
+import (
+	"github.com/spf13/cobra"
+	"github.com/warewulf/warewulf/internal/pkg/wwlog"
+)
+
+func CobraRunE(cmd *cobra.Command, args []string) error {
+	wwlog.Error("This command does not work on non-Linux hosts")
+
+	return nil
+}

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

@@ -0,0 +1,28 @@
+package child
+
+import (
+	"github.com/spf13/cobra"
+)
+
+var (
+	baseCmd = &cobra.Command{
+		DisableFlagsInUseLine: true,
+		Use:                   "__child",
+		Hidden:                true,
+		RunE:                  CobraRunE,
+		Args:                  cobra.MinimumNArgs(1),
+		FParseErrWhitelist:    cobra.FParseErrWhitelist{UnknownFlags: true},
+	}
+	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")
+}
+
+// GetRootCommand returns the root cobra.Command for the application.
+func GetCommand() *cobra.Command {
+	return baseCmd
+}