refactor: centralise tag meta stripping

pkg/recipe/recipe.go

@@ -165,6 +165,9 @@ func (r Recipe) UpdateLabel(pattern, serviceName, label string) error {
 // UpdateTag updates a recipe tag
 func (r Recipe) UpdateTag(image, tag string) error {
 	pattern := fmt.Sprintf("%s/%s/compose**yml", config.RECIPES_DIR, r.Name)
+
+	image = StripTagMeta(image)
+
 	if err := compose.UpdateTag(pattern, image, tag, r.Name); err != nil {
 		return err
 	}
@@ -973,9 +976,8 @@ func GetRecipeVersions(recipeName, registryUsername, registryPassword string) (R
 			}
 
 			path := reference.Path(img)
-			if strings.Contains(path, "library") {
-				path = strings.Split(path, "/")[1]
-			}
+
+			path = StripTagMeta(path)
 
 			var tag string
 			switch img.(type) {
@@ -1041,3 +1043,22 @@ func GetRecipeCatalogueVersions(recipeName string, catl RecipeCatalogue) ([]stri
 
 	return versions, nil
 }
+
+// StripTagMeta strips front-matter image tag data that we don't need for parsing.
+func StripTagMeta(image string) string {
+	originalImage := image
+
+	if strings.Contains(image, "docker.io") {
+		image = strings.Split(image, "/")[1]
+	}
+
+	if strings.Contains(image, "library") {
+		image = strings.Split(image, "/")[1]
+	}
+
+	if originalImage != image {
+		logrus.Debugf("stripped %s to %s for parsing", originalImage, image)
+	}
+
+	return image
+}