github.com/opencontainers/umoci@v0.4.8-0.20240508124516-656e4836fb0d/new.go (about)

     1  /*
     2   * umoci: Umoci Modifies Open Containers' Images
     3   * Copyright (C) 2016-2020 SUSE LLC
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *    http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   */
    17  
    18  package umoci
    19  
    20  import (
    21  	"context"
    22  	"runtime"
    23  	"time"
    24  
    25  	"github.com/apex/log"
    26  	imeta "github.com/opencontainers/image-spec/specs-go"
    27  	ispec "github.com/opencontainers/image-spec/specs-go/v1"
    28  	"github.com/opencontainers/umoci/oci/casext"
    29  	igen "github.com/opencontainers/umoci/oci/config/generate"
    30  	"github.com/pkg/errors"
    31  )
    32  
    33  // NewImage creates a new empty image (tag) in the existing layout.
    34  func NewImage(engineExt casext.Engine, tagName string) error {
    35  	// Create a new manifest.
    36  	log.WithFields(log.Fields{
    37  		"tag": tagName,
    38  	}).Debugf("creating new manifest")
    39  
    40  	// Create a new image config.
    41  	g := igen.New()
    42  	createTime := time.Now()
    43  
    44  	// Set all of the defaults we need.
    45  	g.SetCreated(createTime)
    46  	g.SetOS(runtime.GOOS)
    47  	g.SetArchitecture(runtime.GOARCH)
    48  	g.ClearHistory()
    49  
    50  	// Make sure we have no diffids.
    51  	g.SetRootfsType("layers")
    52  	g.ClearRootfsDiffIDs()
    53  
    54  	// Update config and create a new blob for it.
    55  	config := g.Image()
    56  	configDigest, configSize, err := engineExt.PutBlobJSON(context.Background(), config)
    57  	if err != nil {
    58  		return errors.Wrap(err, "put config blob")
    59  	}
    60  
    61  	log.WithFields(log.Fields{
    62  		"digest": configDigest,
    63  		"size":   configSize,
    64  	}).Debugf("umoci: added new config")
    65  
    66  	// Create a new manifest that just points to the config and has an
    67  	// empty layer set. FIXME: Implement ManifestList support.
    68  	manifest := ispec.Manifest{
    69  		Versioned: imeta.Versioned{
    70  			SchemaVersion: 2, // FIXME: This is hardcoded at the moment.
    71  		},
    72  		MediaType: ispec.MediaTypeImageManifest,
    73  		Config: ispec.Descriptor{
    74  			MediaType: ispec.MediaTypeImageConfig,
    75  			Digest:    configDigest,
    76  			Size:      configSize,
    77  		},
    78  		Layers: []ispec.Descriptor{},
    79  	}
    80  
    81  	manifestDigest, manifestSize, err := engineExt.PutBlobJSON(context.Background(), manifest)
    82  	if err != nil {
    83  		return errors.Wrap(err, "put manifest blob")
    84  	}
    85  
    86  	log.WithFields(log.Fields{
    87  		"digest": manifestDigest,
    88  		"size":   manifestSize,
    89  	}).Debugf("umoci: added new manifest")
    90  
    91  	// Now create a new reference, and either add it to the engine or spew it
    92  	// to stdout.
    93  
    94  	descriptor := ispec.Descriptor{
    95  		// FIXME: Support manifest lists.
    96  		MediaType: ispec.MediaTypeImageManifest,
    97  		Digest:    manifestDigest,
    98  		Size:      manifestSize,
    99  	}
   100  
   101  	log.Infof("new image manifest created: %s", descriptor.Digest)
   102  
   103  	if err := engineExt.UpdateReference(context.Background(), tagName, descriptor); err != nil {
   104  		return errors.Wrap(err, "add new tag")
   105  	}
   106  
   107  	log.Infof("created new tag for image manifest: %s", tagName)
   108  	return nil
   109  }