revert: drop the squash-only image read and bump stereoscope

stereoscope is replacing `image.WithImageSquashOnly` with lazy layer squashes, where every layer keeps a usable squash. That removes the need for `GetSourceConfig.WithImageSquashOnly` and the scope guard in `FileResolver`, so both go.

- bumps stereoscope to `feat/lazy-layer-squashes` (anchore/stereoscope `43c8f7e`), pending that PR merging

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

syft/get_source_config.go

@@ -57,14 +57,6 @@ func (c *GetSourceConfig) WithBasePath(basePath string) *GetSourceConfig {
 	return c
 }
 
-// WithImageSquashOnly reads container images keeping only the image squash, which cuts memory sharply on
-// images with many layers. Only use it when the source will be resolved with source.SquashedScope:
-// any other scope returns an error from FileResolver.
-func (c *GetSourceConfig) WithImageSquashOnly(squashOnly bool) *GetSourceConfig {
-	c.SourceProviderConfig = c.SourceProviderConfig.WithImageSquashOnly(squashOnly)
-	return c
-}
-
 func (c *GetSourceConfig) WithSources(sources ...string) *GetSourceConfig {
 	c.Sources = sources
 	return c

syft/source/sourceproviders/source_provider_config.go

@@ -15,10 +15,6 @@ type Config struct {
 	Exclude          source.ExcludeConfig
 	DigestAlgorithms []crypto.Hash
 	BasePath         string
-	// ImageSquashOnly reads container images keeping only the image squash, dropping the squash every
-	// lower layer would otherwise hold. This cuts memory sharply on images with many layers, but the
-	// resulting source only supports the squashed scope.
-	ImageSquashOnly bool
 }
 
 func (c *Config) WithAlias(alias source.Alias) *Config {
@@ -51,11 +47,6 @@ func (c *Config) WithBasePath(basePath string) *Config {
 	return c
 }
 
-func (c *Config) WithImageSquashOnly(squashOnly bool) *Config {
-	c.ImageSquashOnly = squashOnly
-	return c
-}
-
 func DefaultConfig() *Config {
 	return &Config{
 		DigestAlgorithms: []crypto.Hash{

syft/source/sourceproviders/source_providers.go

@@ -67,9 +67,8 @@ func stereoscopeSourceProviders(userInput string, cfg *Config) collections.Tagge
 			Platform:  cfg.Platform,
 			Registry:  registry,
 		},
-		Alias:           cfg.Alias,
-		Exclude:         cfg.Exclude,
-		ImageSquashOnly: cfg.ImageSquashOnly,
+		Alias:   cfg.Alias,
+		Exclude: cfg.Exclude,
 	})
 	return stereoscopeProviders
 }

syft/source/stereoscopesource/image_source.go

@@ -99,10 +99,6 @@ func (s stereoscopeImageSource) FileResolver(scope source.Scope) (file.Resolver,
 	var res file.Resolver
 	var err error
 
-	if scope != source.SquashedScope && !hasLayerSquashes(s.image) {
-		return nil, fmt.Errorf("the %q scope needs every layer's squashed tree, but the image was read keeping only the image squash", scope)
-	}
-
 	switch scope {
 	case source.SquashedScope:
 		res, err = fileresolver.NewFromContainerImageSquash(s.image)
@@ -126,17 +122,6 @@ func (s stereoscopeImageSource) FileResolver(scope source.Scope) (file.Resolver,
 	return res, nil
 }
 
-// hasLayerSquashes reports whether every layer kept its squashed tree, which is not the case for an image
-// read with image.WithImageSquashOnly (only the top layer keeps one).
-func hasLayerSquashes(img *image.Image) bool {
-	for _, l := range img.Layers {
-		if l.SquashedTree == nil {
-			return false
-		}
-	}
-	return true
-}
-
 func (s stereoscopeImageSource) Close() error {
 	if s.image == nil {
 		return nil

syft/source/stereoscopesource/image_source_provider.go

@@ -15,8 +15,6 @@ type ProviderConfig struct {
 	StereoscopeImageProviderConfig stereoscope.ImageProviderConfig
 	Exclude                        source.ExcludeConfig
 	Alias                          source.Alias
-	// ImageSquashOnly reads the image keeping only the image squash, see image.WithImageSquashOnly
-	ImageSquashOnly bool
 }
 
 type stereoscopeImageSourceProvider struct {
@@ -31,10 +29,6 @@ func (l stereoscopeImageSourceProvider) Name() string {
 }
 
 func (l stereoscopeImageSourceProvider) Provide(ctx context.Context) (source.Source, error) {
-	if l.cfg.ImageSquashOnly {
-		// scoped to this read only, the caller's ctx may be shared with reads that need every layer squash
-		ctx = image.WithImageSquashOnly(ctx)
-	}
 	img, err := l.stereoscopeProvider.Provide(ctx)
 	if err != nil {
 		return nil, err

syft/source/stereoscopesource/image_source_provider_test.go

@@ -1,64 +0,0 @@
-package stereoscopesource
-
-import (
-	"context"
-	"path/filepath"
-	"testing"
-
-	"github.com/google/go-containerregistry/pkg/name"
-	"github.com/google/go-containerregistry/pkg/v1/random"
-	"github.com/google/go-containerregistry/pkg/v1/tarball"
-	"github.com/stretchr/testify/require"
-
-	"github.com/anchore/stereoscope"
-	"github.com/anchore/stereoscope/pkg/image"
-	"github.com/anchore/syft/syft/source"
-)
-
-func Test_stereoscopeImageSourceProvider_imageSquashOnly(t *testing.T) {
-	img, err := random.Image(1024, 3)
-	require.NoError(t, err)
-	tag, err := name.NewTag("localhost/squash-only:latest")
-	require.NoError(t, err)
-	archive := filepath.Join(t.TempDir(), "image.tar")
-	require.NoError(t, tarball.WriteToFile(archive, tag, img))
-
-	provide := func(t *testing.T, squashOnly bool) source.Source {
-		providers := Providers(ProviderConfig{
-			StereoscopeImageProviderConfig: stereoscope.ImageProviderConfig{UserInput: archive},
-			ImageSquashOnly:                squashOnly,
-		})
-		for _, p := range providers {
-			if p.Value.Name() != image.DockerTarballSource {
-				continue
-			}
-			src, err := p.Value.Provide(context.Background())
-			require.NoError(t, err)
-			t.Cleanup(func() { require.NoError(t, src.Close()) })
-			return src
-		}
-		t.Fatalf("no %s provider", image.DockerTarballSource)
-		return nil
-	}
-
-	tests := []struct {
-		name       string
-		squashOnly bool
-		scope      source.Scope
-		wantErr    require.ErrorAssertionFunc
-	}{
-		{name: "full read, squashed", scope: source.SquashedScope, wantErr: require.NoError},
-		{name: "full read, all layers", scope: source.AllLayersScope, wantErr: require.NoError},
-		{name: "full read, deep squashed", scope: source.DeepSquashedScope, wantErr: require.NoError},
-		{name: "squash only, squashed", squashOnly: true, scope: source.SquashedScope, wantErr: require.NoError},
-		// the per-layer resolvers would dereference the dropped layer squashes, so refuse up front
-		{name: "squash only, all layers", squashOnly: true, scope: source.AllLayersScope, wantErr: require.Error},
-		{name: "squash only, deep squashed", squashOnly: true, scope: source.DeepSquashedScope, wantErr: require.Error},
-	}
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			_, err := provide(t, tt.squashOnly).FileResolver(tt.scope)
-			tt.wantErr(t, err)
-		})
-	}
-}