Merge pull request #3939 from zhsj/fix-arm

platforms: fill default arm variant when parse platform specifier

platforms/platforms.go

@@ -189,9 +189,8 @@ func Parse(specifier string) (specs.Platform, error) {
 		if isKnownOS(p.OS) {
 			// picks a default architecture
 			p.Architecture = runtime.GOARCH
-			if p.Architecture == "arm" {
-				// TODO(stevvooe): Resolve arm variant, if not v6 (default)
-				return specs.Platform{}, errors.Wrapf(errdefs.ErrNotImplemented, "arm support not fully implemented")
+			if p.Architecture == "arm" && cpuVariant != "v7" {
+				p.Variant = cpuVariant
 			}
 
 			return p, nil

platforms/platforms_test.go

@@ -28,8 +28,13 @@ func TestParseSelector(t *testing.T) {
 	var (
 		defaultOS      = runtime.GOOS
 		defaultArch    = runtime.GOARCH
+		defaultVariant = ""
 	)
 
+	if defaultArch == "arm" && cpuVariant != "v7" {
+		defaultVariant = cpuVariant
+	}
+
 	for _, testcase := range []struct {
 		skip      bool
 		input     string
@@ -255,8 +260,9 @@ func TestParseSelector(t *testing.T) {
 			expected: specs.Platform{
 				OS:           "linux",
 				Architecture: defaultArch,
+				Variant:      defaultVariant,
 			},
-			formatted: joinNotEmpty("linux", defaultArch),
+			formatted: joinNotEmpty("linux", defaultArch, defaultVariant),
 		},
 		{
 			input: "s390x",
@@ -279,8 +285,9 @@ func TestParseSelector(t *testing.T) {
 			expected: specs.Platform{
 				OS:           "darwin",
 				Architecture: defaultArch,
+				Variant:      defaultVariant,
 			},
-			formatted: joinNotEmpty("darwin", defaultArch),
+			formatted: joinNotEmpty("darwin", defaultArch, defaultVariant),
 		},
 	} {
 		t.Run(testcase.input, func(t *testing.T) {