fix: iterate over existing digests in index

Signed-off-by: Mauren Berti <[email protected]>

internal/provider/structure_test_data_source.go

@@ -150,17 +150,38 @@ func (d *StructureTestDataSource) Read(ctx context.Context, req datasource.ReadR
 		}
 	}
 
-	img, err := desc.Image()
-	if err != nil {
-		resp.Diagnostics.AddError("Unable to load image", fmt.Sprintf("Unable to load image for ref %s, got error: %s", data.Digest.ValueString(), err))
-		return
-	}
+	if desc.MediaType.IsIndex() {
+		index, err := desc.ImageIndex()
+		if err != nil {
+			resp.Diagnostics.AddError("Unable to read image index", fmt.Sprintf("Unable to read image index for ref %s, got error: %s", data.Digest.ValueString(), err))
+			return
+		}
 
-	if err := conds.Check(img); err != nil {
-		data.TestedRef = basetypes.NewStringValue("")
-		data.Id = basetypes.NewStringValue("")
-		resp.Diagnostics.AddError("Image does not match rules", fmt.Sprintf("Image does not match rules:\n%s", err))
-		return
+		indexManifest, err := index.IndexManifest()
+		if err != nil {
+			resp.Diagnostics.AddError("Unable to read image index manifest", fmt.Sprintf("Unable to read image index manifest for ref %s, got error: %s", data.Digest.ValueString(), err))
+			return
+		}
+
+		for _, mDesc := range indexManifest.Manifests {
+			if !mDesc.MediaType.IsImage() {
+				// ignore if not image
+				continue
+			}
+
+			img, err := index.Image(mDesc.Digest)
+			if err != nil {
+				resp.Diagnostics.AddError("Unable to load image", fmt.Sprintf("Unable to load image for ref %s, got error: %s", data.Digest.ValueString(), err))
+				return
+			}
+
+			if err := conds.Check(img); err != nil {
+				data.TestedRef = basetypes.NewStringValue("")
+				data.Id = basetypes.NewStringValue("")
+				resp.Diagnostics.AddError("Image does not match rules", fmt.Sprintf("Image does not match rules:\n%s", err))
+				return
+			}
+		}
 	}
 
 	data.TestedRef = data.Digest