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package crutils
import (
"bytes"
"io"
"os"
"os/exec"
"path/filepath"
metadata "github.com/checkpoint-restore/checkpointctl/lib"
"github.com/containers/storage/pkg/archive"
"github.com/opencontainers/selinux/go-selinux/label"
"github.com/pkg/errors"
)
// This file mainly exist to make the checkpoint/restore functions
// available for other users. One possible candidate would be CRI-O.
// CRImportCheckpointWithoutConfig imports the checkpoint archive (input)
// into the directory destination without "config.dump" and "spec.dump"
func CRImportCheckpointWithoutConfig(destination, input string) error {
archiveFile, err := os.Open(input)
if err != nil {
return errors.Wrapf(err, "Failed to open checkpoint archive %s for import", input)
}
defer archiveFile.Close()
options := &archive.TarOptions{
ExcludePatterns: []string{
// Import everything else besides the container config
metadata.ConfigDumpFile,
metadata.SpecDumpFile,
},
}
if err = archive.Untar(archiveFile, destination, options); err != nil {
return errors.Wrapf(err, "Unpacking of checkpoint archive %s failed", input)
}
return nil
}
// CRRemoveDeletedFiles loads the list of deleted files and if
// it exists deletes all files listed.
func CRRemoveDeletedFiles(id, baseDirectory, containerRootDirectory string) error {
deletedFiles, _, err := metadata.ReadContainerCheckpointDeletedFiles(baseDirectory)
if os.IsNotExist(errors.Unwrap(errors.Unwrap(err))) {
// No files to delete. Just return
return nil
}
if err != nil {
return errors.Wrapf(err, "failed to read deleted files file")
}
for _, deleteFile := range deletedFiles {
// Using RemoveAll as deletedFiles, which is generated from 'podman diff'
// lists completely deleted directories as a single entry: 'D /root'.
if err := os.RemoveAll(filepath.Join(containerRootDirectory, deleteFile)); err != nil {
return errors.Wrapf(err, "failed to delete files from container %s during restore", id)
}
}
return nil
}
// CRApplyRootFsDiffTar applies the tar archive found in baseDirectory with the
// root file system changes on top of containerRootDirectory
func CRApplyRootFsDiffTar(baseDirectory, containerRootDirectory string) error {
rootfsDiffPath := filepath.Join(baseDirectory, metadata.RootFsDiffTar)
if _, err := os.Stat(rootfsDiffPath); err != nil {
// Only do this if a rootfs-diff.tar actually exists
return nil
}
rootfsDiffFile, err := os.Open(rootfsDiffPath)
if err != nil {
return errors.Wrap(err, "failed to open root file-system diff file")
}
defer rootfsDiffFile.Close()
if err := archive.Untar(rootfsDiffFile, containerRootDirectory, nil); err != nil {
return errors.Wrapf(err, "failed to apply root file-system diff file %s", rootfsDiffPath)
}
return nil
}
// CRCreateRootFsDiffTar goes through the 'changes' and can create two files:
// * metadata.RootFsDiffTar will contain all new and changed files
// * metadata.DeletedFilesFile will contain a list of deleted files
// With these two files it is possible to restore the container file system to the same
// state it was during checkpointing.
// Changes to directories (owner, mode) are not handled.
func CRCreateRootFsDiffTar(changes *[]archive.Change, mountPoint, destination string) (includeFiles []string, err error) {
if len(*changes) == 0 {
return includeFiles, nil
}
var rootfsIncludeFiles []string
var deletedFiles []string
rootfsDiffPath := filepath.Join(destination, metadata.RootFsDiffTar)
for _, file := range *changes {
if file.Kind == archive.ChangeAdd {
rootfsIncludeFiles = append(rootfsIncludeFiles, file.Path)
continue
}
if file.Kind == archive.ChangeDelete {
deletedFiles = append(deletedFiles, file.Path)
continue
}
fileName, err := os.Stat(file.Path)
if err != nil {
continue
}
if !fileName.IsDir() && file.Kind == archive.ChangeModify {
rootfsIncludeFiles = append(rootfsIncludeFiles, file.Path)
continue
}
}
if len(rootfsIncludeFiles) > 0 {
rootfsTar, err := archive.TarWithOptions(mountPoint, &archive.TarOptions{
Compression: archive.Uncompressed,
IncludeSourceDir: true,
IncludeFiles: rootfsIncludeFiles,
})
if err != nil {
return includeFiles, errors.Wrapf(err, "error exporting root file-system diff to %q", rootfsDiffPath)
}
rootfsDiffFile, err := os.Create(rootfsDiffPath)
if err != nil {
return includeFiles, errors.Wrapf(err, "error creating root file-system diff file %q", rootfsDiffPath)
}
defer rootfsDiffFile.Close()
if _, err = io.Copy(rootfsDiffFile, rootfsTar); err != nil {
return includeFiles, err
}
includeFiles = append(includeFiles, metadata.RootFsDiffTar)
}
if len(deletedFiles) == 0 {
return includeFiles, nil
}
if _, err := metadata.WriteJSONFile(deletedFiles, destination, metadata.DeletedFilesFile); err != nil {
return includeFiles, nil
}
includeFiles = append(includeFiles, metadata.DeletedFilesFile)
return includeFiles, nil
}
// CRCreateFileWithLabel creates an empty file and sets the corresponding ('fileLabel')
// SELinux label on the file.
// This is necessary for CRIU log files because CRIU infects the processes in
// the container with a 'parasite' and this will also try to write to the log files
// from the context of the container processes.
func CRCreateFileWithLabel(directory, fileName, fileLabel string) error {
logFileName := filepath.Join(directory, fileName)
logFile, err := os.OpenFile(logFileName, os.O_CREATE, 0o600)
if err != nil {
return errors.Wrapf(err, "failed to create file %q", logFileName)
}
defer logFile.Close()
if err = label.SetFileLabel(logFileName, fileLabel); err != nil {
return errors.Wrapf(err, "failed to label file %q", logFileName)
}
return nil
}
// CRRuntimeSupportsCheckpointRestore tests if the given runtime at 'runtimePath'
// supports checkpointing. The checkpoint restore interface has no definition
// but crun implements all commands just as runc does. Whathh runc does it the
// official definition of the checkpoint/restore interface.
func CRRuntimeSupportsCheckpointRestore(runtimePath string) bool {
// Check if the runtime implements checkpointing. Currently only
// runc's and crun's checkpoint/restore implementation is supported.
cmd := exec.Command(runtimePath, "checkpoint", "--help")
if err := cmd.Start(); err != nil {
return false
}
if err := cmd.Wait(); err == nil {
return true
}
return false
}
// CRRuntimeSupportsCheckpointRestore tests if the runtime at 'runtimePath'
// supports restoring into existing Pods. The runtime needs to support
// the CRIU option --lsm-mount-context and the existence of this is checked
// by this function. In addition it is necessary to at least have CRIU 3.16.
func CRRuntimeSupportsPodCheckpointRestore(runtimePath string) bool {
cmd := exec.Command(runtimePath, "restore", "--lsm-mount-context")
out, _ := cmd.CombinedOutput()
return bytes.Contains(out, []byte("flag needs an argument"))
}
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