new(pkg): introduce a function to get all tags from a ref

Signed-off-by: Lorenzo Susini <[email protected]>

Author: loresuso

pkg/oci/tags.go

@@ -0,0 +1,43 @@
+// Copyright 2022 The Falco Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package oci
+
+import (
+	"context"
+
+	"oras.land/oras-go/v2/registry/remote"
+	"oras.land/oras-go/v2/registry/remote/auth"
+)
+
+func Tags(ctx context.Context, ref string, client *auth.Client) ([]string, error) {
+	repository, err := remote.NewRepository(ref)
+	if err != nil {
+		return nil, err
+	}
+	repository.Client = client
+
+	var result []string
+	var tagRetriever = func(tags []string) error {
+		result = tags
+		return nil
+	}
+
+	err = repository.Tags(ctx, "", tagRetriever)
+	if err != nil {
+		return nil, err
+	}
+
+	return result, nil
+}