// Copyright 2019 Google LLC All Rights Reserved. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package compare import ( "errors" "fmt" "reflect" "strings" v1 "github.com/google/go-containerregistry/pkg/v1" "github.com/google/go-containerregistry/pkg/v1/types" ) // Images compares the given images to each other and returns an error if they // differ. func Images(a, b v1.Image) error { digests := []v1.Hash{} manifests := []*v1.Manifest{} cns := []v1.Hash{} sizes := []int64{} mts := []types.MediaType{} layerss := [][]v1.Layer{} errs := []string{} for _, img := range []v1.Image{a, b} { layers, err := img.Layers() if err != nil { return err } layerss = append(layerss, layers) digest, err := img.Digest() if err != nil { return err } digests = append(digests, digest) manifest, err := img.Manifest() if err != nil { return err } manifests = append(manifests, manifest) cn, err := img.ConfigName() if err != nil { return err } cns = append(cns, cn) size, err := img.Size() if err != nil { return err } sizes = append(sizes, size) mt, err := img.MediaType() if err != nil { return err } mts = append(mts, mt) } if want, got := digests[0], digests[1]; want != got { errs = append(errs, fmt.Sprintf("a.Digest() != b.Digest(); %s != %s", want, got)) } if want, got := cns[0], cns[1]; want != got { errs = append(errs, fmt.Sprintf("a.ConfigName() != b.ConfigName(); %s != %s", want, got)) } if want, got := manifests[0], manifests[1]; !reflect.DeepEqual(want, got) { errs = append(errs, fmt.Sprintf("a.Manifest() != b.Manifest(); %v != %v", want, got)) } if want, got := sizes[0], sizes[1]; want != got { errs = append(errs, fmt.Sprintf("a.Size() != b.Size(); %d != %d", want, got)) } if want, got := mts[0], mts[1]; want != got { errs = append(errs, fmt.Sprintf("a.MediaType() != b.MediaType(); %s != %s", want, got)) } if len(layerss[0]) != len(layerss[1]) { // If we have fewer layers than the first image, abort with an error so we don't panic. return errors.New("len(a.Layers()) != len(b.Layers())") } // Compare each layer. for i := 0; i < len(layerss[0]); i++ { if err := Layers(layerss[0][i], layerss[1][i]); err != nil { // Wrap the error in newlines to delineate layer errors. errs = append(errs, fmt.Sprintf("Layers[%d]: %v\n", i, err)) } } if len(errs) != 0 { return errors.New("Images differ:\n" + strings.Join(errs, "\n")) } return nil }