Change platform selection logic

client.go

@@ -102,13 +102,13 @@ func GetImageFromSource(ctx context.Context, imgStr string, source image.Source,
 func selectImageProvider(imgStr string, source image.Source, cfg config) (image.Provider, error) {
 	var provider image.Provider
 	tempDirGenerator := rootTempDirGenerator.NewGenerator()
-
-	if err := setPlatform(source, &cfg, runtime.GOARCH); err != nil {
-		return nil, err
-	}
+	platformSelectionUnsupported := fmt.Errorf("specified platform=%q however image source=%q does not support selecting platform", cfg.Platform.String(), source.String())
 
 	switch source {
 	case image.DockerTarballSource:
+		if cfg.Platform != nil {
+			return nil, platformSelectionUnsupported
+		}
 		// note: the imgStr is the path on disk to the tar file
 		provider = docker.NewProviderFromTarball(imgStr, tempDirGenerator)
 	case image.DockerDaemonSource:
@@ -130,43 +130,36 @@ func selectImageProvider(imgStr string, source image.Source, cfg config) (image.
 			return nil, err
 		}
 	case image.OciDirectorySource:
+		if cfg.Platform != nil {
+			return nil, platformSelectionUnsupported
+		}
 		provider = oci.NewProviderFromPath(imgStr, tempDirGenerator)
 	case image.OciTarballSource:
+		if cfg.Platform != nil {
+			return nil, platformSelectionUnsupported
+		}
 		provider = oci.NewProviderFromTarball(imgStr, tempDirGenerator)
 	case image.OciRegistrySource:
+		defaultPlatformIfNil(&cfg)
 		provider = oci.NewProviderFromRegistry(imgStr, tempDirGenerator, cfg.Registry, cfg.Platform)
 	case image.SingularitySource:
+		if cfg.Platform != nil {
+			return nil, platformSelectionUnsupported
+		}
 		provider = sif.NewProviderFromPath(imgStr, tempDirGenerator)
 	default:
 		return nil, fmt.Errorf("unable to determine image source")
 	}
 	return provider, nil
 }
 
-func setPlatform(source image.Source, cfg *config, defaultArch string) error {
-	// we should override the platform based on the host architecture if the user did not specify a platform
-	// see https://github.com/anchore/stereoscope/issues/149 for more details
-	defaultPlatform, err := image.NewPlatform(defaultArch)
-	if err != nil {
-		log.WithFields("error", err).Warnf("unable to set default platform to %q", runtime.GOARCH)
-		defaultPlatform = nil
-	}
-
-	switch source {
-	case image.DockerTarballSource, image.OciDirectorySource, image.OciTarballSource, image.SingularitySource:
-		if cfg.Platform != nil {
-			return fmt.Errorf("specified platform=%q however image source=%q does not support selecting platform", cfg.Platform.String(), source.String())
-		}
-
-	case image.DockerDaemonSource, image.PodmanDaemonSource, image.OciRegistrySource:
-		if cfg.Platform == nil {
-			cfg.Platform = defaultPlatform
+func defaultPlatformIfNil(cfg *config) {
+	if cfg.Platform == nil {
+		p, err := image.NewPlatform(fmt.Sprintf("linux/%s", runtime.GOARCH))
+		if err == nil {
+			cfg.Platform = p
 		}
-
-	default:
-		return fmt.Errorf("unable to determine image source to select platform")
 	}
-	return nil
 }
 
 // GetImage parses the user provided image string and provides an image object;

test/integration/platform_test.go

@@ -2,7 +2,9 @@ package integration
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
+	"runtime"
 	"strings"
 	"testing"
 
@@ -28,6 +30,12 @@ func TestPlatformSelection(t *testing.T) {
 			os:             "linux",
 			expectedDigest: "sha256:1ee006886991ad4689838d3a288e0dd3fd29b70e276622f16b67a8922831a853", // direct from repo manifest
 		},
+		{
+			source:         image.OciRegistrySource,
+			architecture:   "s390x",
+			os:             "linux",
+			expectedDigest: "sha256:91c15b1ba6f408a648be60f8c047ef79058f26fa640025f374281f31c8704387", // from generated manifest
+		},
 		{
 			source:         image.OciRegistrySource,
 			architecture:   "amd64",
@@ -46,6 +54,12 @@ func TestPlatformSelection(t *testing.T) {
 			os:             "linux",
 			expectedDigest: "sha256:79d3cb76a5a8ba402af164ace87bd0f3e0759979f94caf7247745126359711da", // from generated manifest
 		},
+		{
+			source:         image.DockerDaemonSource,
+			architecture:   "s390x",
+			os:             "linux",
+			expectedDigest: "sha256:91c15b1ba6f408a648be60f8c047ef79058f26fa640025f374281f31c8704387", // from generated manifest
+		},
 		{
 			source:         image.PodmanDaemonSource,
 			architecture:   "arm64",
@@ -71,8 +85,7 @@ func TestPlatformSelection(t *testing.T) {
 			tt.expectedErr(t, err)
 			require.NotNil(t, img)
 
-			assert.Equal(t, tt.os, img.Metadata.OS)
-			assert.Equal(t, tt.architecture, img.Metadata.Architecture)
+			assertArchAndOs(t, img, tt.os, tt.architecture)
 			found := false
 			if img.Metadata.ManifestDigest == tt.expectedDigest {
 				found = true
@@ -89,3 +102,48 @@ func TestPlatformSelection(t *testing.T) {
 		})
 	}
 }
+
+func TestDigestThatNarrowsToOnePlatform(t *testing.T) {
+	// This digest is busybox:1.31 on linux/s390x
+	// Test assumes that the host running these tests _isn't_ linux/s390x, but the behavior
+	// should be the same regardless.
+	imageStrWithDigest := "busybox:1.31@sha256:91c15b1ba6f408a648be60f8c047ef79058f26fa640025f374281f31c8704387"
+	tests := []struct {
+		name   string
+		source image.Source
+	}{
+		{
+			name:   "docker",
+			source: image.DockerDaemonSource,
+		},
+		{
+			name:   "registry",
+			source: image.OciRegistrySource,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			img, err := stereoscope.GetImageFromSource(context.TODO(), imageStrWithDigest, tt.source)
+			assert.NoError(t, err)
+			assertArchAndOs(t, img, "linux", "s390x")
+		})
+	}
+}
+
+func TestDefaultPlatformWithOciRegistry(t *testing.T) {
+	img, err := stereoscope.GetImageFromSource(context.TODO(), "busybox:1.31", image.OciRegistrySource)
+	require.NoError(t, err)
+	assertArchAndOs(t, img, "linux", runtime.GOARCH)
+}
+
+func assertArchAndOs(t *testing.T, img *image.Image, os string, architecture string) {
+	type platform struct {
+		Architecture string `json:"architecture"`
+		Os           string `json:"os"`
+	}
+	var got platform
+	err := json.Unmarshal(img.Metadata.RawConfig, &got)
+	require.NoError(t, err)
+	assert.Equal(t, os, got.Os)
+	assert.Equal(t, architecture, got.Architecture)
+}