github.com/opcr-io/oras-go/v2@v2.0.0-20231122155130-eb4260d8a0ae/registry/remote/manifest.go (about)

     1  /*
     2  Copyright The ORAS Authors.
     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  
    16  package remote
    17  
    18  import (
    19  	"strings"
    20  
    21  	"github.com/opcr-io/oras-go/v2/internal/docker"
    22  	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
    23  )
    24  
    25  // defaultManifestMediaTypes contains the default set of manifests media types.
    26  var defaultManifestMediaTypes = []string{
    27  	docker.MediaTypeManifest,
    28  	docker.MediaTypeManifestList,
    29  	ocispec.MediaTypeImageManifest,
    30  	ocispec.MediaTypeImageIndex,
    31  	ocispec.MediaTypeArtifactManifest,
    32  }
    33  
    34  // defaultManifestAcceptHeader is the default set in the `Accept` header for
    35  // resolving manifests from tags.
    36  var defaultManifestAcceptHeader = strings.Join(defaultManifestMediaTypes, ", ")
    37  
    38  // isManifest determines if the given descriptor points to a manifest.
    39  func isManifest(manifestMediaTypes []string, desc ocispec.Descriptor) bool {
    40  	if len(manifestMediaTypes) == 0 {
    41  		manifestMediaTypes = defaultManifestMediaTypes
    42  	}
    43  	for _, mediaType := range manifestMediaTypes {
    44  		if desc.MediaType == mediaType {
    45  			return true
    46  		}
    47  	}
    48  	return false
    49  }
    50  
    51  // manifestAcceptHeader generates the set in the `Accept` header for resolving
    52  // manifests from tags.
    53  func manifestAcceptHeader(manifestMediaTypes []string) string {
    54  	if len(manifestMediaTypes) == 0 {
    55  		return defaultManifestAcceptHeader
    56  	}
    57  	return strings.Join(manifestMediaTypes, ", ")
    58  }