Refactor pkg packages

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

pkg/cri/opts/container.go

@@ -0,0 +1,118 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package opts
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/containers"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/mount"
+	"github.com/containerd/continuity/fs"
+	"github.com/pkg/errors"
+)
+
+// WithNewSnapshot wraps `containerd.WithNewSnapshot` so that if creating the
+// snapshot fails we make sure the image is actually unpacked and and retry.
+func WithNewSnapshot(id string, i containerd.Image) containerd.NewContainerOpts {
+	f := containerd.WithNewSnapshot(id, i)
+	return func(ctx context.Context, client *containerd.Client, c *containers.Container) error {
+		if err := f(ctx, client, c); err != nil {
+			if !errdefs.IsNotFound(err) {
+				return err
+			}
+
+			if err := i.Unpack(ctx, c.Snapshotter); err != nil {
+				return errors.Wrap(err, "error unpacking image")
+			}
+			return f(ctx, client, c)
+		}
+		return nil
+	}
+}
+
+// WithVolumes copies ownership of volume in rootfs to its corresponding host path.
+// It doesn't update runtime spec.
+// The passed in map is a host path to container path map for all volumes.
+func WithVolumes(volumeMounts map[string]string) containerd.NewContainerOpts {
+	return func(ctx context.Context, client *containerd.Client, c *containers.Container) (err error) {
+		if c.Snapshotter == "" {
+			return errors.New("no snapshotter set for container")
+		}
+		if c.SnapshotKey == "" {
+			return errors.New("rootfs not created for container")
+		}
+		snapshotter := client.SnapshotService(c.Snapshotter)
+		mounts, err := snapshotter.Mounts(ctx, c.SnapshotKey)
+		if err != nil {
+			return err
+		}
+		root, err := ioutil.TempDir("", "ctd-volume")
+		if err != nil {
+			return err
+		}
+		// We change RemoveAll to Remove so that we either leak a temp dir
+		// if it fails but not RM snapshot data.
+		// refer to https://github.com/containerd/containerd/pull/1868
+		// https://github.com/containerd/containerd/pull/1785
+		defer os.Remove(root) // nolint: errcheck
+		if err := mount.All(mounts, root); err != nil {
+			return errors.Wrap(err, "failed to mount")
+		}
+		defer func() {
+			if uerr := mount.Unmount(root, 0); uerr != nil {
+				log.G(ctx).WithError(uerr).Errorf("Failed to unmount snapshot %q", c.SnapshotKey)
+				if err == nil {
+					err = uerr
+				}
+			}
+		}()
+
+		for host, volume := range volumeMounts {
+			src := filepath.Join(root, volume)
+			if _, err := os.Stat(src); err != nil {
+				if os.IsNotExist(err) {
+					// Skip copying directory if it does not exist.
+					continue
+				}
+				return errors.Wrap(err, "stat volume in rootfs")
+			}
+			if err := copyExistingContents(src, host); err != nil {
+				return errors.Wrap(err, "taking runtime copy of volume")
+			}
+		}
+		return nil
+	}
+}
+
+// copyExistingContents copies from the source to the destination and
+// ensures the ownership is appropriately set.
+func copyExistingContents(source, destination string) error {
+	dstList, err := ioutil.ReadDir(destination)
+	if err != nil {
+		return err
+	}
+	if len(dstList) != 0 {
+		return errors.Errorf("volume at %q is not initially empty", destination)
+	}
+	return fs.CopyDir(destination, source)
+}