opts: implement PlatformSlice option

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Author: thaJeztah

opts/platforms.go

@@ -0,0 +1,53 @@
+package opts
+
+import (
+	"strings"
+
+	"github.com/containerd/platforms"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+)
+
+func NewPlatformSlice(val *[]ocispec.Platform) *PlatformSlice {
+	return &PlatformSlice{values: val}
+}
+
+// PlatformSlice is a Value type for passing multiple platforms.
+type PlatformSlice struct {
+	values *[]ocispec.Platform
+}
+
+func (m *PlatformSlice) Set(value string) error {
+	vals := strings.Split(value, ",")
+	for _, val := range vals {
+		p, err := platforms.Parse(val)
+		if err != nil {
+			return err
+		}
+		*m.values = append(*m.values, p)
+	}
+	return nil
+}
+
+// Type returns the type of this option
+func (*PlatformSlice) Type() string {
+	return "platforms"
+}
+
+// String returns a string representation of this option.
+func (m *PlatformSlice) String() string {
+	return strings.Join(m.GetSlice(), ", ")
+}
+
+// GetSlice returns the platforms as a string-slice.
+func (m *PlatformSlice) GetSlice() []string {
+	values := make([]string, 0, len(*m.values))
+	for _, v := range *m.values {
+		values = append(values, platforms.FormatAll(v))
+	}
+	return values
+}
+
+// Value returns the platforms
+func (m *PlatformSlice) Value() []ocispec.Platform {
+	return *m.values
+}