github.com/alibaba/sealer@v0.8.6-0.20220430115802-37a2bdaa8173/pkg/image/store/distribution.go (about)

     1  // Copyright © 2021 Alibaba Group Holding Ltd.
     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 store
    16  
    17  import (
    18  	"encoding/json"
    19  	"os"
    20  	"path/filepath"
    21  
    22  	"github.com/alibaba/sealer/logger"
    23  
    24  	"github.com/opencontainers/go-digest"
    25  
    26  	"github.com/alibaba/sealer/utils"
    27  )
    28  
    29  type DistributionMetadataItem struct {
    30  	SourceRepository   string        `json:"source_repository"`
    31  	LayerContentDigest digest.Digest `json:"layer_content_digest"`
    32  }
    33  
    34  // DistributionMetadata is the data from {layerdb}/distribution_layer_digest
    35  // which indicate that digest of compressedlayerStream in specific registry and repository
    36  type DistributionMetadata []DistributionMetadataItem
    37  
    38  func (fs *filesystem) LoadDistributionMetadata(layerID LayerID) (map[string]digest.Digest, error) {
    39  	var (
    40  		layerDBPath = fs.LayerDBDir(layerID.ToDigest())
    41  		metadatas   = DistributionMetadata{}
    42  		res         = map[string]digest.Digest{}
    43  	)
    44  	distributionMetadataFile, err := os.Open(filepath.Clean(filepath.Join(layerDBPath, "distribution_layer_digest")))
    45  	if err != nil {
    46  		//lint:ignore nilerr https://github.com/alibaba/sealer/issues/610
    47  		return res, nil // ignore
    48  	}
    49  	defer func() {
    50  		if err := distributionMetadataFile.Close(); err != nil {
    51  			logger.Fatal("failed to close file")
    52  		}
    53  	}()
    54  	err = json.NewDecoder(distributionMetadataFile).Decode(&metadatas)
    55  	if err != nil {
    56  		return res, err
    57  	}
    58  
    59  	for _, item := range metadatas {
    60  		res[item.SourceRepository] = item.LayerContentDigest
    61  	}
    62  
    63  	return res, nil
    64  }
    65  
    66  func (fs *filesystem) addDistributionMetadata(layerID LayerID, newMetadatas map[string]digest.Digest) error {
    67  	// load from distribution_layer_digest
    68  	metadataMap, err := fs.LoadDistributionMetadata(layerID)
    69  	if err != nil {
    70  		return err
    71  	}
    72  	// override metadata items, and add new metadata
    73  	for key, value := range newMetadatas {
    74  		metadataMap[key] = value
    75  	}
    76  
    77  	distributionMetadatas := DistributionMetadata{}
    78  	for key, value := range metadataMap {
    79  		distributionMetadatas = append(distributionMetadatas, DistributionMetadataItem{
    80  			SourceRepository:   key,
    81  			LayerContentDigest: value,
    82  		})
    83  	}
    84  
    85  	distributionMetadatasJSON, err := json.Marshal(&distributionMetadatas)
    86  	if err != nil {
    87  		return err
    88  	}
    89  
    90  	return utils.WriteFile(filepath.Join(fs.LayerDBDir(layerID.ToDigest()), "distribution_layer_digest"), distributionMetadatasJSON)
    91  }