github.com/alibaba/sealer@v0.8.6-0.20220430115802-37a2bdaa8173/pkg/image/distributionutil/imagemanifest.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 distributionutil
    16  
    17  import (
    18  	"encoding/json"
    19  	"fmt"
    20  
    21  	"github.com/alibaba/sealer/logger"
    22  	v1 "github.com/alibaba/sealer/types/api/v1"
    23  	platUtil "github.com/alibaba/sealer/utils/platform"
    24  	"github.com/opencontainers/go-digest"
    25  )
    26  
    27  // ManifestList this package unmarshal manifests from json into a ManifestList struct
    28  //then choose corresponding manifest by platform
    29  type ManifestList struct {
    30  	List      []ImageManifest `json:"manifests"`
    31  	MediaType string          `json:"mediaType"`
    32  	Schema    int             `json:"schemaVersion"`
    33  }
    34  
    35  type ImageManifest struct {
    36  	Digest    string `json:"digest"`
    37  	MediaType string `json:"mediaType"`
    38  	Platform  v1.Platform
    39  	Size      int
    40  }
    41  
    42  func GetImageManifestDigest(payload []byte, plat v1.Platform) (digest.Digest, error) {
    43  	var (
    44  		manifestList ManifestList
    45  	)
    46  
    47  	err := json.Unmarshal(payload, &manifestList)
    48  	if err != nil {
    49  		return "", fmt.Errorf("json unmarshal error: %v", err)
    50  	}
    51  
    52  	var resDigest []digest.Digest
    53  	for _, item := range manifestList.List {
    54  		if platUtil.Matched(item.Platform, plat) {
    55  			resDigest = append(resDigest, digest.Digest(item.Digest))
    56  		}
    57  	}
    58  
    59  	if len(resDigest) == 0 {
    60  		return "", fmt.Errorf("no manifest of the corresponding platform")
    61  	}
    62  
    63  	if len(resDigest) > 1 {
    64  		logger.Warn("multiple matches in manifest list")
    65  	}
    66  	return resDigest[0], nil
    67  }