mutate_test.go

// Copyright 2018 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 mutate_test

import (
	"archive/tar"
	"bytes"
	"errors"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	v1 "github.com/google/go-containerregistry/pkg/v1"
	"github.com/google/go-containerregistry/pkg/v1/empty"
	"github.com/google/go-containerregistry/pkg/v1/match"
	"github.com/google/go-containerregistry/pkg/v1/mutate"
	"github.com/google/go-containerregistry/pkg/v1/random"
	"github.com/google/go-containerregistry/pkg/v1/stream"
	"github.com/google/go-containerregistry/pkg/v1/tarball"
	"github.com/google/go-containerregistry/pkg/v1/types"
	"github.com/google/go-containerregistry/pkg/v1/validate"
)

func TestExtractWhiteout(t *testing.T) {
	img, err := tarball.ImageFromPath("testdata/whiteout_image.tar", nil)
	if err != nil {
		t.Errorf("Error loading image: %v", err)
	}
	tarPath, _ := filepath.Abs("img.tar")
	defer os.Remove(tarPath)
	tr := tar.NewReader(mutate.Extract(img))
	for {
		header, err := tr.Next()
		if errors.Is(err, io.EOF) {
			break
		}
		name := header.Name
		for _, part := range filepath.SplitList(name) {
			if part == "foo" {
				t.Errorf("whiteout file found in tar: %v", name)
			}
		}
	}
}

func TestExtractOverwrittenFile(t *testing.T) {
	img, err := tarball.ImageFromPath("testdata/overwritten_file.tar", nil)
	if err != nil {
		t.Fatalf("Error loading image: %v", err)
	}
	tr := tar.NewReader(mutate.Extract(img))
	for {
		header, err := tr.Next()
		if errors.Is(err, io.EOF) {
			break
		}
		name := header.Name
		if strings.Contains(name, "foo.txt") {
			var buf bytes.Buffer
			buf.ReadFrom(tr)
			if strings.Contains(buf.String(), "foo") {
				t.Errorf("Contents of file were not correctly overwritten")
			}
		}
	}
}

// TestExtractError tests that if there are any errors encountered
func TestExtractError(t *testing.T) {
	rc := mutate.Extract(invalidImage{})
	if _, err := io.Copy(ioutil.Discard, rc); err == nil {
		t.Errorf("rc.Read; got nil error")
	} else if !strings.Contains(err.Error(), errInvalidImage.Error()) {
		t.Errorf("rc.Read; got %v, want %v", err, errInvalidImage)
	}
}

// TestExtractPartialRead tests that the reader can be partially read (e.g.,
// tar headers) and closed without error.
func TestExtractPartialRead(t *testing.T) {
	rc := mutate.Extract(invalidImage{})
	if _, err := io.Copy(ioutil.Discard, io.LimitReader(rc, 1)); err != nil {
		t.Errorf("Could not read one byte from reader")
	}
	if err := rc.Close(); err != nil {
		t.Errorf("rc.Close: %v", err)
	}
}

// invalidImage is an image which returns an error when Layers() is called.
type invalidImage struct {
	v1.Image
}

var errInvalidImage = errors.New("invalid image")

func (invalidImage) Layers() ([]v1.Layer, error) {
	return nil, errInvalidImage
}

func TestNoopCondition(t *testing.T) {
	source := sourceImage(t)

	result, err := mutate.AppendLayers(source, []v1.Layer{}...)
	if err != nil {
		t.Fatalf("Unexpected error creating a writable image: %v", err)
	}

	if !manifestsAreEqual(t, source, result) {
		t.Error("manifests are not the same")
	}

	if !configFilesAreEqual(t, source, result) {
		t.Fatal("config files are not the same")
	}
}

func TestAppendWithAddendum(t *testing.T) {
	source := sourceImage(t)

	addendum := mutate.Addendum{
		Layer: mockLayer{},
		History: v1.History{
			Author: "dave",
		},
		URLs: []string{
			"example.com",
		},
		Annotations: map[string]string{
			"foo": "bar",
		},
		MediaType: types.MediaType("foo"),
	}

	result, err := mutate.Append(source, addendum)
	if err != nil {
		t.Fatalf("failed to append: %v", err)
	}

	layers := getLayers(t, result)

	if diff := cmp.Diff(layers[1], mockLayer{}); diff != "" {
		t.Fatalf("correct layer was not appended (-got, +want) %v", diff)
	}

	if configSizesAreEqual(t, source, result) {
		t.Fatal("adding a layer MUST change the config file size")
	}

	cf := getConfigFile(t, result)

	if diff := cmp.Diff(cf.History[1], addendum.History); diff != "" {
		t.Fatalf("the appended history is not the same (-got, +want) %s", diff)
	}

	m, err := result.Manifest()
	if err != nil {
		t.Fatalf("failed to get manifest: %v", err)
	}

	if diff := cmp.Diff(m.Layers[1].URLs, addendum.URLs); diff != "" {
		t.Fatalf("the appended URLs is not the same (-got, +want) %s", diff)
	}

	if diff := cmp.Diff(m.Layers[1].Annotations, addendum.Annotations); diff != "" {
		t.Fatalf("the appended Annotations is not the same (-got, +want) %s", diff)
	}
	if diff := cmp.Diff(m.Layers[1].MediaType, addendum.MediaType); diff != "" {
		t.Fatalf("the appended MediaType is not the same (-got, +want) %s", diff)
	}
}

func TestAppendLayers(t *testing.T) {
	source := sourceImage(t)
	layer, err := random.Layer(100, types.DockerLayer)
	if err != nil {
		t.Fatal(err)
	}
	result, err := mutate.AppendLayers(source, layer)
	if err != nil {
		t.Fatalf("failed to append a layer: %v", err)
	}

	if manifestsAreEqual(t, source, result) {
		t.Fatal("appending a layer did not mutate the manifest")
	}

	if configFilesAreEqual(t, source, result) {
		t.Fatal("appending a layer did not mutate the config file")
	}

	if configSizesAreEqual(t, source, result) {
		t.Fatal("adding a layer MUST change the config file size")
	}

	layers := getLayers(t, result)

	if got, want := len(layers), 2; got != want {
		t.Fatalf("Layers did not return the appended layer "+
			"- got size %d; expected 2", len(layers))
	}

	if layers[1] != layer {
		t.Errorf("correct layer was not appended: got %v; want %v", layers[1], layer)
	}

	if err := validate.Image(result); err != nil {
		t.Errorf("validate.Image() = %v", err)
	}
}

func TestMutateConfig(t *testing.T) {
	source := sourceImage(t)
	cfg, err := source.ConfigFile()
	if err != nil {
		t.Fatalf("error getting source config file")
	}

	newEnv := []string{"foo=bar"}
	cfg.Config.Env = newEnv
	result, err := mutate.Config(source, cfg.Config)
	if err != nil {
		t.Fatalf("failed to mutate a config: %v", err)
	}

	if manifestsAreEqual(t, source, result) {
		t.Error("mutating the config MUST mutate the manifest")
	}

	if configFilesAreEqual(t, source, result) {
		t.Error("mutating the config did not mutate the config file")
	}

	if configSizesAreEqual(t, source, result) {
		t.Error("adding an environment variable MUST change the config file size")
	}

	if configDigestsAreEqual(t, source, result) {
		t.Errorf("mutating the config MUST mutate the config digest")
	}

	if !reflect.DeepEqual(cfg.Config.Env, newEnv) {
		t.Errorf("incorrect environment set %v!=%v", cfg.Config.Env, newEnv)
	}

	if err := validate.Image(result); err != nil {
		t.Errorf("validate.Image() = %v", err)
	}
}

type arbitrary struct {
}

func (arbitrary) RawManifest() ([]byte, error) {
	return []byte(`{"hello":"world"}`), nil
}
func TestAnnotations(t *testing.T) {
	anns := map[string]string{
		"foo": "bar",
	}

	for _, c := range []struct {
		desc string
		in   mutate.Annotatable
		want string
	}{{
		desc: "image",
		in:   empty.Image,
		want: `{"schemaVersion":2,"mediaType":"application/vnd.docker.distribution.manifest.v2+json","config":{"mediaType":"application/vnd.docker.container.image.v1+json","size":115,"digest":"sha256:5b943e2b943f6c81dbbd4e2eca5121f4fcc39139e3d1219d6d89bd925b77d9fe"},"layers":[],"annotations":{"foo":"bar"}}`,
	}, {
		desc: "index",
		in:   empty.Index,
		want: `{"schemaVersion":2,"manifests":null,"annotations":{"foo":"bar"}}`,
	}, {
		desc: "arbitrary",
		in:   arbitrary{},
		want: `{"annotations":{"foo":"bar"},"hello":"world"}`,
	}} {
		t.Run(c.desc, func(t *testing.T) {
			got, err := mutate.Annotations(c.in, anns).RawManifest()
			if err != nil {
				t.Fatalf("Annotations: %v", err)
			}
			if d := cmp.Diff(c.want, string(got)); d != "" {
				t.Errorf("Diff(-want,+got): %s", d)
			}
		})
	}
}

func TestMutateCreatedAt(t *testing.T) {
	source := sourceImage(t)
	want := time.Now().Add(-2 * time.Minute)
	result, err := mutate.CreatedAt(source, v1.Time{Time: want})
	if err != nil {
		t.Fatalf("CreatedAt: %v", err)
	}

	if configDigestsAreEqual(t, source, result) {
		t.Errorf("mutating the created time MUST mutate the config digest")
	}

	got := getConfigFile(t, result).Created.Time
	if got != want {
		t.Errorf("mutating the created time MUST mutate the time from %v to %v", got, want)
	}
}

func TestMutateTime(t *testing.T) {
	source := sourceImage(t)
	want := time.Time{}
	result, err := mutate.Time(source, want)
	if err != nil {
		t.Fatalf("failed to mutate a config: %v", err)
	}

	if configDigestsAreEqual(t, source, result) {
		t.Fatal("mutating the created time MUST mutate the config digest")
	}

	got := getConfigFile(t, result).Created.Time
	if got != want {
		t.Fatalf("mutating the created time MUST mutate the time from %v to %v", got, want)
	}
}

func TestMutateMediaType(t *testing.T) {
	want := types.OCIManifestSchema1
	wantCfg := types.OCIConfigJSON
	img := mutate.MediaType(empty.Image, want)
	img = mutate.ConfigMediaType(img, wantCfg)
	got, err := img.MediaType()
	if err != nil {
		t.Fatal(err)
	}
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	manifest, err := img.Manifest()
	if err != nil {
		t.Fatal(err)
	}
	if manifest.MediaType == "" {
		t.Error("MediaType should be set for OCI media types")
	}
	if gotCfg := manifest.Config.MediaType; gotCfg != wantCfg {
		t.Errorf("manifest.Config.MediaType = %v, wanted %v", gotCfg, wantCfg)
	}

	want = types.DockerManifestSchema2
	wantCfg = types.DockerConfigJSON
	img = mutate.MediaType(img, want)
	img = mutate.ConfigMediaType(img, wantCfg)
	got, err = img.MediaType()
	if err != nil {
		t.Fatal(err)
	}
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	manifest, err = img.Manifest()
	if err != nil {
		t.Fatal(err)
	}
	if manifest.MediaType != want {
		t.Errorf("MediaType should be set for Docker media types: %v", manifest.MediaType)
	}
	if gotCfg := manifest.Config.MediaType; gotCfg != wantCfg {
		t.Errorf("manifest.Config.MediaType = %v, wanted %v", gotCfg, wantCfg)
	}

	want = types.OCIImageIndex
	idx := mutate.IndexMediaType(empty.Index, want)
	got, err = idx.MediaType()
	if err != nil {
		t.Fatal(err)
	}
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	im, err := idx.IndexManifest()
	if err != nil {
		t.Fatal(err)
	}
	if im.MediaType == "" {
		t.Error("MediaType should be set for OCI media types")
	}

	want = types.DockerManifestList
	idx = mutate.IndexMediaType(idx, want)
	got, err = idx.MediaType()
	if err != nil {
		t.Fatal(err)
	}
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	im, err = idx.IndexManifest()
	if err != nil {
		t.Fatal(err)
	}
	if im.MediaType != want {
		t.Errorf("MediaType should be set for Docker media types: %v", im.MediaType)
	}
}

func TestAppendStreamableLayer(t *testing.T) {
	img, err := mutate.AppendLayers(
		sourceImage(t),
		stream.NewLayer(ioutil.NopCloser(strings.NewReader(strings.Repeat("a", 100)))),
		stream.NewLayer(ioutil.NopCloser(strings.NewReader(strings.Repeat("b", 100)))),
		stream.NewLayer(ioutil.NopCloser(strings.NewReader(strings.Repeat("c", 100)))),
	)
	if err != nil {
		t.Fatalf("AppendLayers: %v", err)
	}

	// Until the streams are consumed, the image manifest is not yet computed.
	if _, err := img.Manifest(); !errors.Is(err, stream.ErrNotComputed) {
		t.Errorf("Manifest: got %v, want %v", err, stream.ErrNotComputed)
	}

	// We can still get Layers while some are not yet computed.
	ls, err := img.Layers()
	if err != nil {
		t.Errorf("Layers: %v", err)
	}
	wantDigests := []string{
		"sha256:bfa1c600931132f55789459e2f5a5eb85659ac91bc5a54ce09e3ed14809f8a7f",
		"sha256:77a52b9a141dcc4d3d277d053193765dca725626f50eaf56b903ac2439cf7fd1",
		"sha256:b78472d63f6e3d31059819173b56fcb0d9479a2b13c097d4addd84889f6aff06",
	}
	for i, l := range ls[1:] {
		rc, err := l.Compressed()
		if err != nil {
			t.Errorf("Layer %d Compressed: %v", i, err)
		}

		// Consume the layer's stream and close it to compute the
		// layer's metadata.
		if _, err := io.Copy(ioutil.Discard, rc); err != nil {
			t.Errorf("Reading layer %d: %v", i, err)
		}
		if err := rc.Close(); err != nil {
			t.Errorf("Closing layer %d: %v", i, err)
		}

		// The layer's metadata is now available.
		h, err := l.Digest()
		if err != nil {
			t.Errorf("Digest after consuming layer %d: %v", i, err)
		}
		if h.String() != wantDigests[i] {
			t.Errorf("Layer %d digest got %q, want %q", i, h, wantDigests[i])
		}
	}

	// Now that the streamable layers have been consumed, the image's
	// manifest can be computed.
	if _, err := img.Manifest(); err != nil {
		t.Errorf("Manifest: %v", err)
	}

	h, err := img.Digest()
	if err != nil {
		t.Errorf("Digest: %v", err)
	}
	wantDigest := "sha256:14d140947afedc6901b490265a08bc8ebe7f9d9faed6fdf19a451f054a7dd746"
	if h.String() != wantDigest {
		t.Errorf("Image digest got %q, want %q", h, wantDigest)
	}
}

func TestCanonical(t *testing.T) {
	source := sourceImage(t)
	img, err := mutate.Canonical(source)
	if err != nil {
		t.Fatal(err)
	}
	sourceCf, err := source.ConfigFile()
	if err != nil {
		t.Fatal(err)
	}
	cf, err := img.ConfigFile()
	if err != nil {
		t.Fatal(err)
	}
	for _, h := range cf.History {
		want := "bazel build ..."
		got := h.CreatedBy
		if want != got {
			t.Errorf("%q != %q", want, got)
		}
	}
	var want, got string
	want = cf.Architecture
	got = sourceCf.Architecture
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	want = cf.OS
	got = sourceCf.OS
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	want = cf.OSVersion
	got = sourceCf.OSVersion
	if want != got {
		t.Errorf("%q != %q", want, got)
	}
	for _, s := range []string{
		cf.Container,
		cf.Config.Hostname,
		cf.DockerVersion,
	} {
		if s != "" {
			t.Errorf("non-zeroed string: %v", s)
		}
	}

	expectedLayerTime := time.Unix(0, 0)
	layers := getLayers(t, img)
	for _, layer := range layers {
		assertMTime(t, layer, expectedLayerTime)
	}
}

func TestRemoveManifests(t *testing.T) {
	// Load up the registry.
	count := 3
	for i := 0; i < count; i++ {
		ii, err := random.Index(1024, int64(count), int64(count))
		if err != nil {
			t.Fatal(err)
		}
		// test removing the first layer, second layer or the third layer
		manifest, err := ii.IndexManifest()
		if err != nil {
			t.Fatal(err)
		}
		if len(manifest.Manifests) != count {
			t.Fatalf("mismatched manifests on setup, had %d, expected %d", len(manifest.Manifests), count)
		}
		digest := manifest.Manifests[i].Digest
		ii = mutate.RemoveManifests(ii, match.Digests(digest))
		manifest, err = ii.IndexManifest()
		if err != nil {
			t.Fatal(err)
		}
		if len(manifest.Manifests) != (count - 1) {
			t.Fatalf("mismatched manifests after removal, had %d, expected %d", len(manifest.Manifests), count-1)
		}
		for j, m := range manifest.Manifests {
			if m.Digest == digest {
				t.Fatalf("unexpectedly found removed hash %v at position %d", digest, j)
			}
		}
	}
}

func TestImageImmutability(t *testing.T) {
	img := mutate.MediaType(empty.Image, types.OCIManifestSchema1)

	t.Run("manifest", func(t *testing.T) {
		// Check that Manifest is immutable.
		changed, err := img.Manifest()
		if err != nil {
			t.Errorf("Manifest() = %v", err)
		}
		want := changed.DeepCopy() // Create a copy of original before mutating it.
		changed.MediaType = types.DockerManifestList

		if got, err := img.Manifest(); err != nil {
			t.Errorf("Manifest() = %v", err)
		} else if !cmp.Equal(got, want) {
			t.Errorf("manifest changed! %s", cmp.Diff(got, want))
		}
	})

	t.Run("config file", func(t *testing.T) {
		// Check that ConfigFile is immutable.
		changed, err := img.ConfigFile()
		if err != nil {
			t.Errorf("ConfigFile() = %v", err)
		}
		want := changed.DeepCopy() // Create a copy of original before mutating it.
		changed.Author = "Jay Pegg"

		if got, err := img.ConfigFile(); err != nil {
			t.Errorf("ConfigFile() = %v", err)
		} else if !cmp.Equal(got, want) {
			t.Errorf("ConfigFile changed! %s", cmp.Diff(got, want))
		}
	})
}

func assertMTime(t *testing.T, layer v1.Layer, expectedTime time.Time) {
	l, err := layer.Uncompressed()

	if err != nil {
		t.Fatalf("reading layer failed: %v", err)
	}

	tr := tar.NewReader(l)
	for {
		header, err := tr.Next()
		if errors.Is(err, io.EOF) {
			break
		}
		if err != nil {
			t.Fatalf("Error reading layer: %v", err)
		}

		mtime := header.ModTime
		if mtime.Equal(expectedTime) == false {
			t.Errorf("unexpected mod time for layer. expected %v, got %v.", expectedTime, mtime)
		}
	}
}

func sourceImage(t *testing.T) v1.Image {
	t.Helper()

	image, err := tarball.ImageFromPath("testdata/source_image.tar", nil)
	if err != nil {
		t.Fatalf("Error loading image: %v", err)
	}
	return image
}

func getManifest(t *testing.T, i v1.Image) *v1.Manifest {
	t.Helper()

	m, err := i.Manifest()
	if err != nil {
		t.Fatalf("Error fetching image manifest: %v", err)
	}

	return m
}

func getLayers(t *testing.T, i v1.Image) []v1.Layer {
	t.Helper()

	l, err := i.Layers()
	if err != nil {
		t.Fatalf("Error fetching image layers: %v", err)
	}

	return l
}

func getConfigFile(t *testing.T, i v1.Image) *v1.ConfigFile {
	t.Helper()

	c, err := i.ConfigFile()
	if err != nil {
		t.Fatalf("Error fetching image config file: %v", err)
	}

	return c
}

func configFilesAreEqual(t *testing.T, first, second v1.Image) bool {
	t.Helper()

	fc := getConfigFile(t, first)
	sc := getConfigFile(t, second)

	return cmp.Equal(fc, sc)
}

func configDigestsAreEqual(t *testing.T, first, second v1.Image) bool {
	t.Helper()

	fm := getManifest(t, first)
	sm := getManifest(t, second)

	return fm.Config.Digest == sm.Config.Digest
}

func configSizesAreEqual(t *testing.T, first, second v1.Image) bool {
	t.Helper()

	fm := getManifest(t, first)
	sm := getManifest(t, second)

	return fm.Config.Size == sm.Config.Size
}

func manifestsAreEqual(t *testing.T, first, second v1.Image) bool {
	t.Helper()

	fm := getManifest(t, first)
	sm := getManifest(t, second)

	return cmp.Equal(fm, sm)
}

type mockLayer struct{}

func (m mockLayer) Digest() (v1.Hash, error) {
	return v1.Hash{Algorithm: "fake", Hex: "digest"}, nil
}

func (m mockLayer) DiffID() (v1.Hash, error) {
	return v1.Hash{Algorithm: "fake", Hex: "diff id"}, nil
}

func (m mockLayer) MediaType() (types.MediaType, error) {
	return "some-media-type", nil
}

func (m mockLayer) Size() (int64, error) { return 137438691328, nil }
func (m mockLayer) Compressed() (io.ReadCloser, error) {
	return ioutil.NopCloser(strings.NewReader("compressed times")), nil
}
func (m mockLayer) Uncompressed() (io.ReadCloser, error) {
	return ioutil.NopCloser(strings.NewReader("uncompressed")), nil
}