From 05549e8b2904427a1fb6d0b36889ac43360db073 Mon Sep 17 00:00:00 2001 From: Adrian Reber Date: Thu, 27 Jun 2019 07:56:39 +0000 Subject: Add --ignore-rootfs option for checkpoint/restore The newly added functionality to include the container's root file-system changes into the checkpoint archive can now be explicitly disabled. Either during checkpoint or during restore. If a container changes a lot of files during its runtime it might be more effective to migrated the root file-system changes in some other way and to not needlessly increase the size of the checkpoint archive. If a checkpoint archive does not contain the root file-system changes information it will automatically be skipped. If the root file-system changes are part of the checkpoint archive it is also possible to tell Podman to ignore these changes. Signed-off-by: Adrian Reber --- cmd/podman/checkpoint.go | 1 + cmd/podman/cliconfig/config.go | 2 + cmd/podman/restore.go | 5 +++ completions/bash/podman | 2 + docs/podman-container-checkpoint.1.md | 10 ++++- docs/podman-container-restore.1.md | 7 ++++ libpod/container_api.go | 3 ++ libpod/container_internal_linux.go | 73 +++++++++++++++++++---------------- pkg/adapter/containers.go | 5 +++ pkg/adapter/containers_remote.go | 6 +++ 10 files changed, 79 insertions(+), 35 deletions(-) diff --git a/cmd/podman/checkpoint.go b/cmd/podman/checkpoint.go index 6755bb073..22cdb1f39 100644 --- a/cmd/podman/checkpoint.go +++ b/cmd/podman/checkpoint.go @@ -46,6 +46,7 @@ func init() { flags.BoolVarP(&checkpointCommand.All, "all", "a", false, "Checkpoint all running containers") flags.BoolVarP(&checkpointCommand.Latest, "latest", "l", false, "Act on the latest container podman is aware of") flags.StringVarP(&checkpointCommand.Export, "export", "e", "", "Export the checkpoint image to a tar.gz") + flags.BoolVar(&checkpointCommand.IgnoreRootfs, "ignore-rootfs", false, "Do not include root file-system changes when exporting") markFlagHiddenForRemoteClient("latest", flags) } diff --git a/cmd/podman/cliconfig/config.go b/cmd/podman/cliconfig/config.go index e3e2edb95..be380cda0 100644 --- a/cmd/podman/cliconfig/config.go +++ b/cmd/podman/cliconfig/config.go @@ -92,6 +92,7 @@ type CheckpointValues struct { All bool Latest bool Export string + IgnoreRootfs bool } type CommitValues struct { @@ -433,6 +434,7 @@ type RestoreValues struct { TcpEstablished bool Import string Name string + IgnoreRootfs bool } type RmValues struct { diff --git a/cmd/podman/restore.go b/cmd/podman/restore.go index 7ecec24ee..3ae141d41 100644 --- a/cmd/podman/restore.go +++ b/cmd/podman/restore.go @@ -45,6 +45,7 @@ func init() { flags.BoolVar(&restoreCommand.TcpEstablished, "tcp-established", false, "Restore a container with established TCP connections") flags.StringVarP(&restoreCommand.Import, "import", "i", "", "Restore from exported checkpoint archive (tar.gz)") flags.StringVarP(&restoreCommand.Name, "name", "n", "", "Specify new name for container restored from exported checkpoint (only works with --import)") + flags.BoolVar(&restoreCommand.IgnoreRootfs, "ignore-rootfs", false, "Do not apply root file-system changes when importing from exported checkpoint") markFlagHiddenForRemoteClient("latest", flags) } @@ -60,6 +61,10 @@ func restoreCmd(c *cliconfig.RestoreValues, cmd *cobra.Command) error { } defer runtime.DeferredShutdown(false) + if c.Import == "" && c.IgnoreRootfs { + return errors.Errorf("--ignore-rootfs can only be used with --import") + } + if c.Import == "" && c.Name != "" { return errors.Errorf("--name can only be used with --import") } diff --git a/completions/bash/podman b/completions/bash/podman index 65c6308cc..619c9e1e6 100644 --- a/completions/bash/podman +++ b/completions/bash/podman @@ -758,6 +758,7 @@ _podman_container_checkpoint() { -R --leave-running --tcp-established + --ignore-rootfs " case "$prev" in -e|--export) @@ -870,6 +871,7 @@ _podman_container_restore() { -l --latest --tcp-established + --ignore-rootfs " case "$prev" in -i|--import) diff --git a/docs/podman-container-checkpoint.1.md b/docs/podman-container-checkpoint.1.md index 90c3919a9..034d338bb 100644 --- a/docs/podman-container-checkpoint.1.md +++ b/docs/podman-container-checkpoint.1.md @@ -42,7 +42,15 @@ connections. Export the checkpoint to a tar.gz file. The exported checkpoint can be used to import the container on another system and thus enabling container live -migration. +migration. This checkpoint archive also includes all changes to the container's +root file-system, if not explicitly disabled using **--ignore-rootfs** + +**--ignore-rootfs** + +This only works in combination with **--export, -e**. If a checkpoint is +exported to a tar.gz file it is possible with the help of **--ignore-rootfs** +to explicitly disable including changes to the root file-system into +the checkpoint archive file. ## EXAMPLE diff --git a/docs/podman-container-restore.1.md b/docs/podman-container-restore.1.md index c96a37f80..544a096d8 100644 --- a/docs/podman-container-restore.1.md +++ b/docs/podman-container-restore.1.md @@ -60,6 +60,13 @@ address to the container it was using before checkpointing as each IP address ca be used once and the restored container will have another IP address. This also means that **--name, -n** cannot be used in combination with **--tcp-established**. +**--ignore-rootfs** + +This is only available in combination with **--import, -i**. If a container is restored +from a checkpoint tar.gz file it is possible that it also contains all root file-system +changes. With **--ignore-rootfs** it is possible to explicitly disable applying these +root file-system changes to the restored container. + ## EXAMPLE podman container restore mywebserver diff --git a/libpod/container_api.go b/libpod/container_api.go index 00467d2bf..c6e478846 100644 --- a/libpod/container_api.go +++ b/libpod/container_api.go @@ -799,6 +799,9 @@ type ContainerCheckpointOptions struct { // checkpoint archive a new name should be used for the // restored container Name string + // IgnoreRootfs tells the API to not export changes to + // the container's root file-system (or to not import) + IgnoreRootfs bool } // Checkpoint checkpoints a container diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 77f607f0b..399220b9a 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -510,41 +510,44 @@ func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr return nil } -func (c *Container) exportCheckpoint(dest string) (err error) { +func (c *Container) exportCheckpoint(dest string, ignoreRootfs bool) (err error) { if (len(c.config.NamedVolumes) > 0) || (len(c.Dependencies()) > 0) { return errors.Errorf("Cannot export checkpoints of containers with named volumes or dependencies") } logrus.Debugf("Exporting checkpoint image of container %q to %q", c.ID(), dest) + includeFiles := []string{ + "checkpoint", + "artifacts", + "ctr.log", + "config.dump", + "spec.dump", + "network.status"} + // Get root file-system changes included in the checkpoint archive rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar") - 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()) - 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) + 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()) + 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) + } + tarStream.Close() + rootfsDiffFile.Close() + includeFiles = append(includeFiles, "rootfs-diff.tar") } - tarStream.Close() - rootfsDiffFile.Close() - input, err := archive.TarWithOptions(c.bundlePath(), &archive.TarOptions{ Compression: archive.Gzip, IncludeSourceDir: true, - IncludeFiles: []string{ - "checkpoint", - "artifacts", - "ctr.log", - "config.dump", - "spec.dump", - "rootfs-diff.tar", - "network.status"}, + IncludeFiles: includeFiles, }) if err != nil { @@ -627,7 +630,7 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO } if options.TargetFile != "" { - if err = c.exportCheckpoint(options.TargetFile); err != nil { + if err = c.exportCheckpoint(options.TargetFile, options.IgnoreRootfs); err != nil { return err } } @@ -816,17 +819,19 @@ func (c *Container) restore(ctx context.Context, options ContainerCheckpointOpti } // Before actually restarting the container, apply the root file-system changes - rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar") - if _, err := os.Stat(rootfsDiffPath); err == nil { - // Only do this if a rootfs-diff.tar actually exists - rootfsDiffFile, err := os.Open(rootfsDiffPath) - if err != nil { - return errors.Wrapf(err, "Failed to open root file-system diff file %s", rootfsDiffPath) - } - if err := c.runtime.ApplyDiffTarStream(c.ID(), rootfsDiffFile); err != nil { - return errors.Wrapf(err, "Failed to apply root file-system diff file %s", rootfsDiffPath) + if !options.IgnoreRootfs { + rootfsDiffPath := filepath.Join(c.bundlePath(), "rootfs-diff.tar") + if _, err := os.Stat(rootfsDiffPath); err == nil { + // Only do this if a rootfs-diff.tar actually exists + rootfsDiffFile, err := os.Open(rootfsDiffPath) + if err != nil { + return errors.Wrapf(err, "Failed to open root file-system diff file %s", rootfsDiffPath) + } + 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() } - rootfsDiffFile.Close() } if err := c.ociRuntime.createContainer(c, c.config.CgroupParent, &options); err != nil { diff --git a/pkg/adapter/containers.go b/pkg/adapter/containers.go index 1cf9d686a..e0245d2ac 100644 --- a/pkg/adapter/containers.go +++ b/pkg/adapter/containers.go @@ -524,6 +524,10 @@ func (r *LocalRuntime) Checkpoint(c *cliconfig.CheckpointValues) error { KeepRunning: c.LeaveRunning, TCPEstablished: c.TcpEstablished, TargetFile: c.Export, + IgnoreRootfs: c.IgnoreRootfs, + } + if c.Export == "" && c.IgnoreRootfs { + return errors.Errorf("--ignore-rootfs can only be used with --export") } if c.All { containers, err = r.Runtime.GetRunningContainers() @@ -560,6 +564,7 @@ func (r *LocalRuntime) Restore(ctx context.Context, c *cliconfig.RestoreValues) TCPEstablished: c.TcpEstablished, TargetFile: c.Import, Name: c.Name, + IgnoreRootfs: c.IgnoreRootfs, } filterFuncs = append(filterFuncs, func(c *libpod.Container) bool { diff --git a/pkg/adapter/containers_remote.go b/pkg/adapter/containers_remote.go index 5836d0788..5e8df1b62 100644 --- a/pkg/adapter/containers_remote.go +++ b/pkg/adapter/containers_remote.go @@ -668,6 +668,9 @@ func (r *LocalRuntime) Checkpoint(c *cliconfig.CheckpointValues) error { if c.Export != "" { return errors.New("the remote client does not support exporting checkpoints") } + if c.IgnoreRootfs { + return errors.New("the remote client does not support --ignore-rootfs") + } var lastError error ids, err := iopodman.GetContainersByContext().Call(r.Conn, c.All, c.Latest, c.InputArgs) @@ -708,6 +711,9 @@ func (r *LocalRuntime) Restore(ctx context.Context, c *cliconfig.RestoreValues) if c.Import != "" { return errors.New("the remote client does not support importing checkpoints") } + if c.IgnoreRootfs { + return errors.New("the remote client does not support --ignore-rootfs") + } var lastError error ids, err := iopodman.GetContainersByContext().Call(r.Conn, c.All, c.Latest, c.InputArgs) -- cgit v1.2.3-54-g00ecf