1 files changed, 53 insertions, 0 deletions
diff --git a/app/services/packages/helm/extract_file_metadata_service.rb b/app/services/packages/helm/extract_file_metadata_service.rb
new file mode 100644
index 00000000000..e7373d8ea8f
--- /dev/null
+++ b/app/services/packages/helm/extract_file_metadata_service.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require 'rubygems/package'
+
+module Packages
+  module Helm
+    class ExtractFileMetadataService
+      ExtractionError = Class.new(StandardError)
+
+      def initialize(package_file)
+        @package_file = package_file
+      end
+
+      def execute
+        raise ExtractionError, 'invalid package file' unless valid_package_file?
+
+        metadata
+      end
+
+      private
+
+      def valid_package_file?
+        @package_file &&
+          @package_file.package&.helm? &&
+          @package_file.file.size > 0 # rubocop:disable Style/ZeroLengthPredicate
+      end
+
+      def metadata
+        YAML.safe_load(chart_yaml_content)
+      rescue Psych::Exception => e
+        raise ExtractionError, "Error while parsing Chart.yaml: #{e.message}"
+      end
+
+      def chart_yaml_content
+        @package_file.file.use_open_file do |file|
+          tar_reader = Gem::Package::TarReader.new(Zlib::GzipReader.new(file))
+
+          chart_yaml = tar_reader.find do |entry|
+            next unless entry.file?
+
+            entry.full_name.end_with?('/Chart.yaml')
+          end
+
+          raise ExtractionError, 'Chart.yaml not found within a directory' unless chart_yaml
+
+          chart_yaml.read
+        ensure
+          tar_reader.close
+        end
+      end
+    end
+  end
+end