From 225c7ae6c98300fc8d9536fa31c0ae9f8231c5c0 Mon Sep 17 00:00:00 2001 From: Adrian Reber Date: Wed, 4 Dec 2019 15:06:51 +0000 Subject: Correctly export the root file-system changes When doing a checkpoint with --export the root file-system diff was not working as expected. Instead of getting the changes from the running container to the highest storage layer it got the changes from the highest layer to that parent's layer. For a one layer container this could mean that the complete root file-system is part of the checkpoint. With this commit this changes to use the same functionality as 'podman diff'. This actually enables to correctly diff the root file-system including tracking deleted files. This also removes the non-working helper functions from libpod/diff.go. Signed-off-by: Adrian Reber --- libpod/container_internal_linux.go | 98 +++++++++++++++++++++++++++++++++----- 1 file changed, 85 insertions(+), 13 deletions(-) (limited to 'libpod/container_internal_linux.go') diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 1b0570998..6ec06943f 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -593,22 +593,68 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) (err error) // Get root file-system changes included in the checkpoint archive rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar") + deleteFilesList := filepath.Join(c.bundlePath(), "deleted.files") if !ignoreRootfs { - rootfsDiffFile, err := os.Create(rootfsDiffPath) - if err != nil { - return errors.Wrapf(err, "error creating root file-system diff file %q", rootfsDiffPath) - } - tarStream, err := c.runtime.GetDiffTarStream("", c.ID()) + // To correctly track deleted files, let's go through the output of 'podman diff' + tarFiles, err := c.runtime.GetDiff("", c.ID()) if err != nil { return errors.Wrapf(err, "error exporting root file-system diff to %q", rootfsDiffPath) } - _, err = io.Copy(rootfsDiffFile, tarStream) - if err != nil { - return errors.Wrapf(err, "error exporting root file-system diff to %q", rootfsDiffPath) + var rootfsIncludeFiles []string + var deletedFiles []string + + for _, file := range tarFiles { + 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(c.state.Mountpoint, &archive.TarOptions{ + Compression: archive.Uncompressed, + IncludeSourceDir: true, + IncludeFiles: rootfsIncludeFiles, + }) + if err != nil { + return errors.Wrapf(err, "error exporting root file-system diff to %q", rootfsDiffPath) + } + rootfsDiffFile, err := os.Create(rootfsDiffPath) + if err != nil { + return errors.Wrapf(err, "error creating root file-system diff file %q", rootfsDiffPath) + } + defer rootfsDiffFile.Close() + _, err = io.Copy(rootfsDiffFile, rootfsTar) + if err != nil { + return err + } + + includeFiles = append(includeFiles, "rootfs-diff.tar") + } + + if len(deletedFiles) > 0 { + formatJSON, err := json.MarshalIndent(deletedFiles, "", " ") + if err != nil { + return errors.Wrapf(err, "error creating delete files list file %q", deleteFilesList) + } + if err := ioutil.WriteFile(deleteFilesList, formatJSON, 0600); err != nil { + return errors.Wrapf(err, "error creating delete files list file %q", deleteFilesList) + } + + includeFiles = append(includeFiles, "deleted.files") } - tarStream.Close() - rootfsDiffFile.Close() - includeFiles = append(includeFiles, "rootfs-diff.tar") } input, err := archive.TarWithOptions(c.bundlePath(), &archive.TarOptions{ @@ -637,6 +683,7 @@ func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) (err error) } os.Remove(rootfsDiffPath) + os.Remove(deleteFilesList) return nil } @@ -941,10 +988,35 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti if err != nil { return errors.Wrapf(err, "Failed to open root file-system diff file %s", rootfsDiffPath) } + defer rootfsDiffFile.Close() if err := c.runtime.ApplyDiffTarStream(c.ID(), rootfsDiffFile); err != nil { return errors.Wrapf(err, "Failed to apply root file-system diff file %s", rootfsDiffPath) } - rootfsDiffFile.Close() + } + deletedFilesPath := filepath.Join(c.bundlePath(), "deleted.files") + if _, err := os.Stat(deletedFilesPath); err == nil { + deletedFilesFile, err := os.Open(deletedFilesPath) + if err != nil { + return errors.Wrapf(err, "Failed to open deleted files file %s", deletedFilesPath) + } + defer deletedFilesFile.Close() + + var deletedFiles []string + deletedFilesJSON, err := ioutil.ReadAll(deletedFilesFile) + if err != nil { + return errors.Wrapf(err, "Failed to read deleted files file %s", deletedFilesPath) + } + if err := json.Unmarshal(deletedFilesJSON, &deletedFiles); err != nil { + return errors.Wrapf(err, "Failed to read deleted files file %s", deletedFilesPath) + } + for _, deleteFile := range deletedFiles { + // Using RemoveAll as deletedFiles, which is generated from 'podman diff' + // lists completely deleted directories as a single entry: 'D /root'. + err = os.RemoveAll(filepath.Join(c.state.Mountpoint, deleteFile)) + if err != nil { + return errors.Wrapf(err, "Failed to delete file %s from container %s during restore", deletedFilesPath, c.ID()) + } + } } } @@ -965,7 +1037,7 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti if err != nil { logrus.Debugf("Non-fatal: removal of checkpoint directory (%s) failed: %v", c.CheckpointPath(), err) } - cleanup := [...]string{"restore.log", "dump.log", "stats-dump", "stats-restore", "network.status", "rootfs-diff.tar"} + cleanup := [...]string{"restore.log", "dump.log", "stats-dump", "stats-restore", "network.status", "rootfs-diff.tar", "deleted.files"} for _, del := range cleanup { file := filepath.Join(c.bundlePath(), del) err = os.Remove(file) -- cgit v1.2.3-54-g00ecf