Files
warewulf/internal/app/wwctl/container/exec/child/main.go
Christian Goll 457c7c16b1 wwctl commands without NodeInfo
mostly remove Get and calls for the id

Signed-off-by: Christian Goll <cgoll@suse.com>
2024-10-17 13:35:42 -04:00

216 lines
7.4 KiB
Go

//go:build linux
// +build linux
package child
import (
"fmt"
"os"
"path"
"path/filepath"
"strings"
"syscall"
"github.com/pkg/errors"
"github.com/spf13/cobra"
warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
"github.com/warewulf/warewulf/internal/pkg/container"
"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)`
const msgStr = `Container image is rebuilt depending on the exit status of the last command.
Run "true" or "false" to enforce or abort image rebuild.`
func CobraRunE(cmd *cobra.Command, args []string) (err error) {
if os.Getpid() != 1 {
return fmt.Errorf("PID is not 1: %d", os.Getpid())
}
containerName := args[0]
if !container.ValidSource(containerName) {
return fmt.Errorf("unknown Warewulf container: %s", containerName)
}
conf := warewulfconf.Get()
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", 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()
}
}
containerPath := container.RootFsDir(containerName)
// 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 errors.Wrap(err, "failed to mount")
}
ps1Str := fmt.Sprintf("[%s|%s] Warewulf> ", containerName, exitEval)
wwlog.Info(msgStr)
if len(lowerObjects) != 0 && nodename == "" {
options := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s",
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 {
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)
}
nodes, err := nodeDB.FindAllNodes()
if err != nil {
return fmt.Errorf("could not get node list: %s", err)
}
nodes = node.FilterByName(nodes, []string{nodename})
if len(nodes) != 1 {
return fmt.Errorf("no single node idendified with %s", nodename)
}
overlays := nodes[0].SystemOverlay
overlays = append(overlays, nodes[0].RuntimeOverlay...)
err = overlay.BuildOverlayIndir(nodes[0], 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"), containerPath, path.Join(runDir, "nodeoverlay"))
wwlog.Debug("overlay options: %s", options)
err = syscall.Mount("overlay", containerPath, "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> ", containerName, nodename)
}
if !util.IsWriteAble(containerPath) && nodename == "" {
wwlog.Verbose("mounting %s ro", containerPath)
ps1Str = fmt.Sprintf("[%s|ro] Warewulf> ", containerName)
err = syscall.Mount(containerPath, containerPath, "", syscall.MS_BIND, "")
if err != nil {
return errors.Wrap(err, "failed to prepare bind mount")
}
err = syscall.Mount(containerPath, containerPath, "", syscall.MS_REMOUNT|syscall.MS_RDONLY|syscall.MS_BIND, "")
if err != nil {
return errors.Wrap(err, "failed to remount ro")
}
}
for _, mntPnt := range mountPts {
if mntPnt.Copy {
continue
}
wwlog.Debug("bind mounting: %s -> %s", mntPnt.Source, path.Join(containerPath, mntPnt.Dest))
err = syscall.Mount(mntPnt.Source, path.Join(containerPath, 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(containerPath, 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 container: %s:%s", mntPnt.Source, mntPnt.Dest)
}
} else {
wwlog.Verbose("mounted from host to container: %s:%s", mntPnt.Source, mntPnt.Dest)
}
}
err = syscall.Chroot(containerPath)
if err != nil {
return errors.Wrap(err, "failed to chroot")
}
err = os.Chdir("/")
if err != nil {
return errors.Wrap(err, "failed to chdir")
}
if err := syscall.Mount("devtmpfs", "/dev", "devtmpfs", 0, ""); err != nil {
return errors.Wrap(err, "failed to mount /dev")
}
if err := syscall.Mount("sysfs", "/sys", "sysfs", 0, ""); err != nil {
return errors.Wrap(err, "failed to mount /sys")
}
if err := syscall.Mount("proc", "/proc", "proc", 0, ""); err != nil {
return errors.Wrap(err, "failed to mount /proc")
}
if err := syscall.Mount("tmpfs", "/run", "tmpfs", 0, ""); err != nil {
return errors.Wrap(err, "failed to mount /run")
}
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 container. Returns
the invalid mount points. Directories always have '/' as suffix
*/
func checkMountPoints(containerName 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 container", b.Source)
continue
}
wwlog.Debug("Checking in container for %s", path.Join(container.RootFsDir(containerName), b.Dest))
if _, err = os.Stat(path.Join(container.RootFsDir(containerName), 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("Container %s, needs following path: %s", containerName, b.Dest)
}
}
}
return overlayObjects
}