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authorAdrian Reber <areber@redhat.com>2019-02-06 19:17:25 +0000
committerAdrian Reber <areber@redhat.com>2019-06-03 22:05:12 +0200
commita05cfd24bb6929ca4431f9169b9b215b0d43d91e (patch)
treef24a4482f609119b98770896f365d630c4af5c2d /libpod
parente0c8c14f5be5a2da38683f35e55d19ffc36659ba (diff)
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Added helper functions for container migration
This adds a couple of function in structure members needed in the next commit to make container migration actually work. This just splits of the function which are not modifying existing code. Signed-off-by: Adrian Reber <areber@redhat.com>
Diffstat (limited to 'libpod')
-rw-r--r--libpod/container_api.go5
-rw-r--r--libpod/container_internal.go38
-rw-r--r--libpod/container_internal_linux.go81
3 files changed, 120 insertions, 4 deletions
diff --git a/libpod/container_api.go b/libpod/container_api.go
index eff5bfe5f..b8b60a6e2 100644
--- a/libpod/container_api.go
+++ b/libpod/container_api.go
@@ -815,6 +815,11 @@ type ContainerCheckpointOptions struct {
// TCPEstablished tells the API to checkpoint a container
// even if it contains established TCP connections
TCPEstablished bool
+ // Export tells the API to write the checkpoint image to
+ // the filename set in TargetFile
+ // Import tells the API to read the checkpoint image from
+ // the filename set in TargetFile
+ TargetFile string
}
// Checkpoint checkpoints a container
diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index 5f8dd1c72..42f56e82f 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -21,6 +21,7 @@ import (
"github.com/containers/storage/pkg/archive"
"github.com/containers/storage/pkg/mount"
spec "github.com/opencontainers/runtime-spec/specs-go"
+ "github.com/opencontainers/runtime-tools/generate"
"github.com/opencontainers/selinux/go-selinux/label"
opentracing "github.com/opentracing/opentracing-go"
"github.com/pkg/errors"
@@ -1501,3 +1502,40 @@ func (c *Container) checkReadyForRemoval() error {
return nil
}
+
+// writeJSONFile marshalls and writes the given data to a JSON file
+// in the bundle path
+func (c *Container) writeJSONFile(v interface{}, file string) (err error) {
+ fileJSON, err := json.MarshalIndent(v, "", " ")
+ if err != nil {
+ return errors.Wrapf(err, "error writing JSON to %s for container %s", file, c.ID())
+ }
+ file = filepath.Join(c.bundlePath(), file)
+ if err := ioutil.WriteFile(file, fileJSON, 0644); err != nil {
+ return err
+ }
+
+ return nil
+}
+
+// prepareCheckpointExport writes the config and spec to
+// JSON files for later export
+func (c *Container) prepareCheckpointExport() (err error) {
+ // save live config
+ if err := c.writeJSONFile(c.Config(), "config.dump"); err != nil {
+ return err
+ }
+
+ // save spec
+ jsonPath := filepath.Join(c.bundlePath(), "config.json")
+ g, err := generate.NewFromFile(jsonPath)
+ if err != nil {
+ logrus.Debugf("generating spec for container %q failed with %v", c.ID(), err)
+ return err
+ }
+ if err := c.writeJSONFile(g.Spec(), "spec.dump"); err != nil {
+ return err
+ }
+
+ return nil
+}
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index f25f76092..3c02e3ae0 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -5,6 +5,7 @@ package libpod
import (
"context"
"fmt"
+ "io"
"io/ioutil"
"net"
"os"
@@ -25,6 +26,7 @@ import (
"github.com/containers/libpod/pkg/lookup"
"github.com/containers/libpod/pkg/resolvconf"
"github.com/containers/libpod/pkg/rootless"
+ "github.com/containers/storage/pkg/archive"
securejoin "github.com/cyphar/filepath-securejoin"
"github.com/opencontainers/runc/libcontainer/user"
spec "github.com/opencontainers/runtime-spec/specs-go"
@@ -496,6 +498,42 @@ func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr
return nil
}
+func (c *Container) exportCheckpoint(dest string) (err error) {
+ logrus.Debugf("Exporting checkpoint image of container %q to %q", c.ID(), dest)
+ input, err := archive.TarWithOptions(c.bundlePath(), &archive.TarOptions{
+ Compression: archive.Gzip,
+ IncludeSourceDir: true,
+ IncludeFiles: []string{
+ "checkpoint",
+ "artifacts",
+ "ctr.log",
+ "config.dump",
+ "spec.dump",
+ "network.status"},
+ })
+
+ if err != nil {
+ return errors.Wrapf(err, "error reading checkpoint directory %q", c.ID())
+ }
+
+ outFile, err := os.Create(dest)
+ if err != nil {
+ return errors.Wrapf(err, "error creating checkpoint export file %q", dest)
+ }
+ defer outFile.Close()
+
+ if err := os.Chmod(dest, 0600); err != nil {
+ return errors.Wrapf(err, "cannot chmod %q", dest)
+ }
+
+ _, err = io.Copy(outFile, input)
+ if err != nil {
+ return err
+ }
+
+ return nil
+}
+
func (c *Container) checkpointRestoreSupported() (err error) {
if !criu.CheckForCriu() {
return errors.Errorf("Checkpoint/Restore requires at least CRIU %d", criu.MinCriuVersion)
@@ -561,15 +599,50 @@ func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointO
}
if !options.Keep {
- // Remove log file
- os.Remove(filepath.Join(c.bundlePath(), "dump.log"))
- // Remove statistic file
- os.Remove(filepath.Join(c.bundlePath(), "stats-dump"))
+ cleanup := []string{
+ "dump.log",
+ "stats-dump",
+ "config.dump",
+ "spec.dump",
+ }
+ for _, delete := range cleanup {
+ file := filepath.Join(c.bundlePath(), delete)
+ os.Remove(file)
+ }
}
return c.save()
}
+func (c *Container) importCheckpoint(input string) (err 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{
+ // config.dump and spec.dump are only required
+ // container creation
+ "config.dump",
+ "spec.dump",
+ },
+ }
+ err = archive.Untar(archiveFile, c.bundlePath(), options)
+ if err != nil {
+ return errors.Wrapf(err, "Unpacking of checkpoint archive %s failed", input)
+ }
+
+ // Make sure the newly created config.json exists on disk
+ g := generate.NewFromSpec(c.config.Spec)
+ if err = c.saveSpec(g.Spec()); err != nil {
+ return errors.Wrap(err, "Saving imported container specification for restore failed")
+ }
+
+ return nil
+}
+
func (c *Container) restore(ctx context.Context, options ContainerCheckpointOptions) (err error) {
if err := c.checkpointRestoreSupported(); err != nil {