Move client to subpackage

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

client/install.go

@@ -0,0 +1,128 @@
+/*
+   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 client
+
+import (
+	"archive/tar"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+
+	"github.com/containerd/containerd/v2/archive"
+	"github.com/containerd/containerd/v2/archive/compression"
+	"github.com/containerd/containerd/v2/content"
+	"github.com/containerd/containerd/v2/images"
+)
+
+// Install a binary image into the opt service.
+// More info: https://github.com/containerd/containerd/blob/main/docs/managed-opt.md.
+func (c *Client) Install(ctx context.Context, image Image, opts ...InstallOpts) error {
+	var config InstallConfig
+	for _, o := range opts {
+		o(&config)
+	}
+	path, err := c.getInstallPath(ctx, config)
+	if err != nil {
+		return err
+	}
+	var (
+		cs       = image.ContentStore()
+		platform = c.platform
+	)
+	manifest, err := images.Manifest(ctx, cs, image.Target(), platform)
+	if err != nil {
+		return err
+	}
+
+	var binDir, libDir string
+	if runtime.GOOS == "windows" {
+		binDir = "Files\\bin"
+		libDir = "Files\\lib"
+	} else {
+		binDir = "bin"
+		libDir = "lib"
+	}
+	for _, layer := range manifest.Layers {
+		ra, err := cs.ReaderAt(ctx, layer)
+		if err != nil {
+			return err
+		}
+		cr := content.NewReader(ra)
+		r, err := compression.DecompressStream(cr)
+		if err != nil {
+			ra.Close()
+			return err
+		}
+
+		filter := archive.WithFilter(func(hdr *tar.Header) (bool, error) {
+			d := filepath.Dir(hdr.Name)
+			result := d == binDir
+
+			if config.Libs {
+				result = result || d == libDir
+			}
+
+			if runtime.GOOS == "windows" {
+				hdr.Name = strings.Replace(hdr.Name, "Files", "", 1)
+			}
+			if result && !config.Replace {
+				if _, err := os.Lstat(filepath.Join(path, hdr.Name)); err == nil {
+					return false, fmt.Errorf("cannot replace %s in %s", hdr.Name, path)
+				}
+			}
+			return result, nil
+		})
+
+		opts := []archive.ApplyOpt{filter}
+
+		if runtime.GOOS == "windows" {
+			opts = append(opts, archive.WithNoSameOwner())
+		}
+
+		if _, err := archive.Apply(ctx, path, r, opts...); err != nil {
+			r.Close()
+			ra.Close()
+			return err
+		}
+		r.Close()
+		ra.Close()
+	}
+	return nil
+}
+
+func (c *Client) getInstallPath(ctx context.Context, config InstallConfig) (string, error) {
+	if config.Path != "" {
+		return config.Path, nil
+	}
+	filters := []string{"id==opt"}
+	resp, err := c.IntrospectionService().Plugins(ctx, filters)
+	if err != nil {
+		return "", err
+	}
+	if len(resp.Plugins) != 1 {
+		return "", errors.New("opt service not enabled")
+	}
+	path := resp.Plugins[0].Exports["path"]
+	if path == "" {
+		return "", errors.New("opt path not exported")
+	}
+	return path, nil
+}