index.go

Documentation: github.com/google/go-containerregistry/pkg/v1/mutate

     1  // Copyright 2019 Google LLC All Rights Reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //    http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package mutate
    16  
    17  import (
    18  	"encoding/json"
    19  	"errors"
    20  	"fmt"
    21  	"sync"
    22  
    23  	"github.com/google/go-containerregistry/pkg/logs"
    24  	v1 "github.com/google/go-containerregistry/pkg/v1"
    25  	"github.com/google/go-containerregistry/pkg/v1/match"
    26  	"github.com/google/go-containerregistry/pkg/v1/partial"
    27  	"github.com/google/go-containerregistry/pkg/v1/stream"
    28  	"github.com/google/go-containerregistry/pkg/v1/types"
    29  )
    30  
    31  func computeDescriptor(ia IndexAddendum) (*v1.Descriptor, error) {
    32  	desc, err := partial.Descriptor(ia.Add)
    33  	if err != nil {
    34  		return nil, err
    35  	}
    36  
    37  	// The IndexAddendum allows overriding Descriptor values.
    38  	if ia.Descriptor.Size != 0 {
    39  		desc.Size = ia.Descriptor.Size
    40  	}
    41  	if string(ia.Descriptor.MediaType) != "" {
    42  		desc.MediaType = ia.Descriptor.MediaType
    43  	}
    44  	if ia.Descriptor.Digest != (v1.Hash{}) {
    45  		desc.Digest = ia.Descriptor.Digest
    46  	}
    47  	if ia.Descriptor.Platform != nil {
    48  		desc.Platform = ia.Descriptor.Platform
    49  	}
    50  	if len(ia.Descriptor.URLs) != 0 {
    51  		desc.URLs = ia.Descriptor.URLs
    52  	}
    53  	if len(ia.Descriptor.Annotations) != 0 {
    54  		desc.Annotations = ia.Descriptor.Annotations
    55  	}
    56  	if ia.Descriptor.Data != nil {
    57  		desc.Data = ia.Descriptor.Data
    58  	}
    59  
    60  	return desc, nil
    61  }
    62  
    63  type index struct {
    64  	base v1.ImageIndex
    65  	adds []IndexAddendum
    66  	// remove is removed before adds
    67  	remove match.Matcher
    68  
    69  	computed    bool
    70  	manifest    *v1.IndexManifest
    71  	annotations map[string]string
    72  	mediaType   *types.MediaType
    73  	imageMap    map[v1.Hash]v1.Image
    74  	indexMap    map[v1.Hash]v1.ImageIndex
    75  	layerMap    map[v1.Hash]v1.Layer
    76  	subject     *v1.Descriptor
    77  
    78  	sync.Mutex
    79  }
    80  
    81  var _ v1.ImageIndex = (*index)(nil)
    82  
    83  func (i *index) MediaType() (types.MediaType, error) {
    84  	if i.mediaType != nil {
    85  		return *i.mediaType, nil
    86  	}
    87  	return i.base.MediaType()
    88  }
    89  
    90  func (i *index) Size() (int64, error) { return partial.Size(i) }
    91  
    92  func (i *index) compute() error {
    93  	i.Lock()
    94  	defer i.Unlock()
    95  
    96  	// Don't re-compute if already computed.
    97  	if i.computed {
    98  		return nil
    99  	}
   100  
   101  	i.imageMap = make(map[v1.Hash]v1.Image)
   102  	i.indexMap = make(map[v1.Hash]v1.ImageIndex)
   103  	i.layerMap = make(map[v1.Hash]v1.Layer)
   104  
   105  	m, err := i.base.IndexManifest()
   106  	if err != nil {
   107  		return err
   108  	}
   109  	manifest := m.DeepCopy()
   110  	manifests := manifest.Manifests
   111  
   112  	if i.remove != nil {
   113  		var cleanedManifests []v1.Descriptor
   114  		for _, m := range manifests {
   115  			if !i.remove(m) {
   116  				cleanedManifests = append(cleanedManifests, m)
   117  			}
   118  		}
   119  		manifests = cleanedManifests
   120  	}
   121  
   122  	for _, add := range i.adds {
   123  		desc, err := computeDescriptor(add)
   124  		if err != nil {
   125  			return err
   126  		}
   127  
   128  		manifests = append(manifests, *desc)
   129  		if idx, ok := add.Add.(v1.ImageIndex); ok {
   130  			i.indexMap[desc.Digest] = idx
   131  		} else if img, ok := add.Add.(v1.Image); ok {
   132  			i.imageMap[desc.Digest] = img
   133  		} else if l, ok := add.Add.(v1.Layer); ok {
   134  			i.layerMap[desc.Digest] = l
   135  		} else {
   136  			logs.Warn.Printf("Unexpected index addendum: %T", add.Add)
   137  		}
   138  	}
   139  
   140  	manifest.Manifests = manifests
   141  
   142  	if i.mediaType != nil {
   143  		manifest.MediaType = *i.mediaType
   144  	}
   145  
   146  	if i.annotations != nil {
   147  		if manifest.Annotations == nil {
   148  			manifest.Annotations = map[string]string{}
   149  		}
   150  		for k, v := range i.annotations {
   151  			manifest.Annotations[k] = v
   152  		}
   153  	}
   154  	manifest.Subject = i.subject
   155  
   156  	i.manifest = manifest
   157  	i.computed = true
   158  	return nil
   159  }
   160  
   161  func (i *index) Image(h v1.Hash) (v1.Image, error) {
   162  	if img, ok := i.imageMap[h]; ok {
   163  		return img, nil
   164  	}
   165  	return i.base.Image(h)
   166  }
   167  
   168  func (i *index) ImageIndex(h v1.Hash) (v1.ImageIndex, error) {
   169  	if idx, ok := i.indexMap[h]; ok {
   170  		return idx, nil
   171  	}
   172  	return i.base.ImageIndex(h)
   173  }
   174  
   175  type withLayer interface {
   176  	Layer(v1.Hash) (v1.Layer, error)
   177  }
   178  
   179  // Workaround for #819.
   180  func (i *index) Layer(h v1.Hash) (v1.Layer, error) {
   181  	if layer, ok := i.layerMap[h]; ok {
   182  		return layer, nil
   183  	}
   184  	if wl, ok := i.base.(withLayer); ok {
   185  		return wl.Layer(h)
   186  	}
   187  	return nil, fmt.Errorf("layer not found: %s", h)
   188  }
   189  
   190  // Digest returns the sha256 of this image's manifest.
   191  func (i *index) Digest() (v1.Hash, error) {
   192  	if err := i.compute(); err != nil {
   193  		return v1.Hash{}, err
   194  	}
   195  	return partial.Digest(i)
   196  }
   197  
   198  // Manifest returns this image's Manifest object.
   199  func (i *index) IndexManifest() (*v1.IndexManifest, error) {
   200  	if err := i.compute(); err != nil {
   201  		return nil, err
   202  	}
   203  	return i.manifest.DeepCopy(), nil
   204  }
   205  
   206  // RawManifest returns the serialized bytes of Manifest()
   207  func (i *index) RawManifest() ([]byte, error) {
   208  	if err := i.compute(); err != nil {
   209  		return nil, err
   210  	}
   211  	return json.Marshal(i.manifest)
   212  }
   213  
   214  func (i *index) Manifests() ([]partial.Describable, error) {
   215  	if err := i.compute(); errors.Is(err, stream.ErrNotComputed) {
   216  		// Index contains a streamable layer which has not yet been
   217  		// consumed. Just return the manifests we have in case the caller
   218  		// is going to consume the streamable layers.
   219  		manifests, err := partial.Manifests(i.base)
   220  		if err != nil {
   221  			return nil, err
   222  		}
   223  		for _, add := range i.adds {
   224  			manifests = append(manifests, add.Add)
   225  		}
   226  		return manifests, nil
   227  	} else if err != nil {
   228  		return nil, err
   229  	}
   230  
   231  	return partial.ComputeManifests(i)
   232  }
   233
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