1 // Copyright 2023 CUE Labs AG 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 ocifilter 16 17 import "cuelabs.dev/go/oci/ociregistry" 18 19 // ReadOnly returns a registry implementation that returns 20 // an "operation unsupported" error from all entry points that 21 // mutate the registry. 22 func ReadOnly(r ociregistry.Interface) ociregistry.Interface { 23 // One level deeper so the Reader and Lister values take precedence, 24 // following Go's shallower-method-wins rules. 25 type deeper struct { 26 *ociregistry.Funcs 27 } 28 return struct { 29 ociregistry.Reader 30 ociregistry.Lister 31 deeper 32 }{ 33 Reader: r, 34 Lister: r, 35 } 36 } 37