Re-add list-buckets.rb (remove after docs update)

Author: remi Taylor

storage/list_buckets.rb

@@ -0,0 +1,58 @@
+#!/usr/bin/env ruby
+
+# Copyright 2015 Google, Inc.
+#
+# 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.
+
+module Samples
+  # Cloud Storage Samples module
+  module Storage
+    # A short sample demonstrating making an authenticated api request.
+    #
+    # Specifically, it creates a Service object to the Google Cloud Storage api,
+    # and uses Application Default Credentials to authenticate.
+    # [START all]
+    class ListBuckets
+      # [START list_buckets]
+      require "google/apis/storage_v1"
+
+      # Alias the Google Cloud Storage module
+      Storage = Google::Apis::StorageV1
+
+      def list_buckets project_id
+        # Create the storage service object, used to access the storage api.
+        storage = Storage::StorageService.new
+        # Have the service object use the application default credentials to
+        # auth, which infers credentials from the environment.
+        storage.authorization = Google::Auth.get_application_default(
+          # Set the credentials to have a readonly scope to the storage service.
+          Storage::AUTH_DEVSTORAGE_READ_ONLY
+        )
+
+        # Make the api call to list buckets owned by the default credentials.
+        storage.list_buckets(project_id).items.each do |bucket|
+          # Print out each bucket name.
+          puts bucket.name
+        end
+      end
+      # [END list_buckets]
+    end
+
+    if __FILE__ == $PROGRAM_NAME
+      project_id = ARGV.shift
+
+      ListBuckets.new.list_buckets project_id
+    end
+    # [END all]
+  end
+end