Move runtime to core/runtime

Signed-off-by: Derek McGowan <derek@mcg.dev>

core/runtime/v2/bundle.go

@@ -0,0 +1,169 @@
+/*
+   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 v2
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+
+	"github.com/containerd/containerd/v2/core/mount"
+	"github.com/containerd/containerd/v2/pkg/identifiers"
+	"github.com/containerd/containerd/v2/pkg/namespaces"
+	"github.com/containerd/containerd/v2/pkg/oci"
+	"github.com/containerd/typeurl/v2"
+	"github.com/opencontainers/runtime-spec/specs-go"
+)
+
+// LoadBundle loads an existing bundle from disk
+func LoadBundle(ctx context.Context, root, id string) (*Bundle, error) {
+	ns, err := namespaces.NamespaceRequired(ctx)
+	if err != nil {
+		return nil, err
+	}
+	return &Bundle{
+		ID:        id,
+		Path:      filepath.Join(root, ns, id),
+		Namespace: ns,
+	}, nil
+}
+
+// NewBundle returns a new bundle on disk
+func NewBundle(ctx context.Context, root, state, id string, spec typeurl.Any) (b *Bundle, err error) {
+	if err := identifiers.Validate(id); err != nil {
+		return nil, fmt.Errorf("invalid task id %s: %w", id, err)
+	}
+
+	ns, err := namespaces.NamespaceRequired(ctx)
+	if err != nil {
+		return nil, err
+	}
+	work := filepath.Join(root, ns, id)
+	b = &Bundle{
+		ID:        id,
+		Path:      filepath.Join(state, ns, id),
+		Namespace: ns,
+	}
+	var paths []string
+	defer func() {
+		if err != nil {
+			for _, d := range paths {
+				os.RemoveAll(d)
+			}
+		}
+	}()
+	// create state directory for the bundle
+	if err := os.MkdirAll(filepath.Dir(b.Path), 0711); err != nil {
+		return nil, err
+	}
+	if err := os.Mkdir(b.Path, 0700); err != nil {
+		return nil, err
+	}
+	if typeurl.Is(spec, &specs.Spec{}) {
+		if err := prepareBundleDirectoryPermissions(b.Path, spec.GetValue()); err != nil {
+			return nil, err
+		}
+	}
+	paths = append(paths, b.Path)
+	// create working directory for the bundle
+	if err := os.MkdirAll(filepath.Dir(work), 0711); err != nil {
+		return nil, err
+	}
+	rootfs := filepath.Join(b.Path, "rootfs")
+	if err := os.MkdirAll(rootfs, 0711); err != nil {
+		return nil, err
+	}
+	paths = append(paths, rootfs)
+	if err := os.Mkdir(work, 0711); err != nil {
+		if !os.IsExist(err) {
+			return nil, err
+		}
+		os.RemoveAll(work)
+		if err := os.Mkdir(work, 0711); err != nil {
+			return nil, err
+		}
+	}
+	paths = append(paths, work)
+	// symlink workdir
+	if err := os.Symlink(work, filepath.Join(b.Path, "work")); err != nil {
+		return nil, err
+	}
+	if spec := spec.GetValue(); spec != nil {
+		// write the spec to the bundle
+		specPath := filepath.Join(b.Path, oci.ConfigFilename)
+		err = os.WriteFile(specPath, spec, 0666)
+		if err != nil {
+			return nil, fmt.Errorf("failed to write bundle spec: %w", err)
+		}
+	}
+	return b, nil
+}
+
+// Bundle represents an OCI bundle
+type Bundle struct {
+	// ID of the bundle
+	ID string
+	// Path to the bundle
+	Path string
+	// Namespace of the bundle
+	Namespace string
+}
+
+// Delete a bundle atomically
+func (b *Bundle) Delete() error {
+	work, werr := os.Readlink(filepath.Join(b.Path, "work"))
+	rootfs := filepath.Join(b.Path, "rootfs")
+	if runtime.GOOS != "darwin" {
+		if err := mount.UnmountRecursive(rootfs, 0); err != nil {
+			return fmt.Errorf("unmount rootfs %s: %w", rootfs, err)
+		}
+	}
+	if err := os.Remove(rootfs); err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("failed to remove bundle rootfs: %w", err)
+	}
+	err := atomicDelete(b.Path)
+	if err == nil {
+		if werr == nil {
+			return atomicDelete(work)
+		}
+		return nil
+	}
+	// error removing the bundle path; still attempt removing work dir
+	var err2 error
+	if werr == nil {
+		err2 = atomicDelete(work)
+		if err2 == nil {
+			return err
+		}
+	}
+	return fmt.Errorf("failed to remove both bundle and workdir locations: %v: %w", err2, err)
+}
+
+// atomicDelete renames the path to a hidden file before removal
+func atomicDelete(path string) error {
+	// create a hidden dir for an atomic removal
+	atomicPath := filepath.Join(filepath.Dir(path), fmt.Sprintf(".%s", filepath.Base(path)))
+	if err := os.Rename(path, atomicPath); err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		}
+		return err
+	}
+	return os.RemoveAll(atomicPath)
+}