github.com/containerd/nerdctl/v2@v2.0.0-beta.5.0.20240520001846-b5758f54fa28/pkg/cmd/image/load.go (about)

     1  /*
     2     Copyright The containerd Authors.
     3  
     4     Licensed under the Apache License, Version 2.0 (the "License");
     5     you may not use this file except in compliance with the License.
     6     You may obtain a copy of the License at
     7  
     8         http://www.apache.org/licenses/LICENSE-2.0
     9  
    10     Unless required by applicable law or agreed to in writing, software
    11     distributed under the License is distributed on an "AS IS" BASIS,
    12     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13     See the License for the specific language governing permissions and
    14     limitations under the License.
    15  */
    16  
    17  package image
    18  
    19  import (
    20  	"context"
    21  	"errors"
    22  	"fmt"
    23  	"io"
    24  	"os"
    25  
    26  	"github.com/containerd/containerd"
    27  	"github.com/containerd/containerd/archive/compression"
    28  	"github.com/containerd/containerd/images"
    29  	"github.com/containerd/containerd/images/archive"
    30  	"github.com/containerd/nerdctl/v2/pkg/api/types"
    31  	"github.com/containerd/nerdctl/v2/pkg/imgutil"
    32  	"github.com/containerd/nerdctl/v2/pkg/platformutil"
    33  	"github.com/containerd/platforms"
    34  )
    35  
    36  type readCounter struct {
    37  	io.Reader
    38  	N int
    39  }
    40  
    41  func (r *readCounter) Read(p []byte) (int, error) {
    42  	n, err := r.Reader.Read(p)
    43  	if n > 0 {
    44  		r.N += n
    45  	}
    46  	return n, err
    47  }
    48  
    49  func Load(ctx context.Context, client *containerd.Client, options types.ImageLoadOptions) error {
    50  	if options.Input != "" {
    51  		f, err := os.Open(options.Input)
    52  		if err != nil {
    53  			return err
    54  		}
    55  		defer f.Close()
    56  		options.Stdin = f
    57  	} else {
    58  		// check if stdin is empty.
    59  		stdinStat, err := os.Stdin.Stat()
    60  		if err != nil {
    61  			return err
    62  		}
    63  		if stdinStat.Size() == 0 && (stdinStat.Mode()&os.ModeNamedPipe) == 0 {
    64  			return errors.New("stdin is empty and input flag is not specified")
    65  		}
    66  	}
    67  	decompressor, err := compression.DecompressStream(options.Stdin)
    68  	if err != nil {
    69  		return err
    70  	}
    71  	platMC, err := platformutil.NewMatchComparer(options.AllPlatforms, options.Platform)
    72  	if err != nil {
    73  		return err
    74  	}
    75  	return loadImage(ctx, client, decompressor, platMC, false, options)
    76  }
    77  
    78  func loadImage(ctx context.Context, client *containerd.Client, in io.Reader, platMC platforms.MatchComparer, quiet bool, options types.ImageLoadOptions) error {
    79  	// In addition to passing WithImagePlatform() to client.Import(), we also need to pass WithDefaultPlatform() to NewClient().
    80  	// Otherwise unpacking may fail.
    81  	r := &readCounter{Reader: in}
    82  	imgs, err := client.Import(ctx, r, containerd.WithDigestRef(archive.DigestTranslator(options.GOptions.Snapshotter)), containerd.WithSkipDigestRef(func(name string) bool { return name != "" }), containerd.WithImportPlatform(platMC))
    83  	if err != nil {
    84  		if r.N == 0 {
    85  			// Avoid confusing "unrecognized image format"
    86  			return errors.New("no image was built")
    87  		}
    88  		if errors.Is(err, images.ErrEmptyWalk) {
    89  			err = fmt.Errorf("%w (Hint: set `--platform=PLATFORM` or `--all-platforms`)", err)
    90  		}
    91  		return err
    92  	}
    93  	for _, img := range imgs {
    94  		image := containerd.NewImageWithPlatform(client, img, platMC)
    95  
    96  		// TODO: Show unpack status
    97  		if !quiet {
    98  			fmt.Fprintf(options.Stdout, "unpacking %s (%s)...\n", img.Name, img.Target.Digest)
    99  		}
   100  		err = image.Unpack(ctx, options.GOptions.Snapshotter)
   101  		if err != nil {
   102  			return err
   103  		}
   104  		if quiet {
   105  			fmt.Fprintln(options.Stdout, img.Target.Digest)
   106  		} else {
   107  			repo, tag := imgutil.ParseRepoTag(img.Name)
   108  			fmt.Fprintf(options.Stdout, "Loaded image: %s:%s\n", repo, tag)
   109  		}
   110  	}
   111  
   112  	return nil
   113  }