1 files changed, 127 insertions, 0 deletions
diff --git a/app/services/security/ci_configuration/sast_parser_service.rb b/app/services/security/ci_configuration/sast_parser_service.rb
new file mode 100644
index 00000000000..a8fe5764d19
--- /dev/null
+++ b/app/services/security/ci_configuration/sast_parser_service.rb
@@ -0,0 +1,127 @@
+# frozen_string_literal: true
+
+module Security
+  module CiConfiguration
+    # This class parses SAST template file and .gitlab-ci.yml to populate default and current values into the JSON
+    # read from app/validators/json_schemas/security_ci_configuration_schemas/sast_ui_schema.json
+    class SastParserService < ::BaseService
+      include Gitlab::Utils::StrongMemoize
+
+      SAST_UI_SCHEMA_PATH = 'app/validators/json_schemas/security_ci_configuration_schemas/sast_ui_schema.json'
+
+      def initialize(project)
+        @project = project
+      end
+
+      def configuration
+        result = Gitlab::Json.parse(File.read(Rails.root.join(SAST_UI_SCHEMA_PATH))).with_indifferent_access
+        populate_default_value_for(result, :global)
+        populate_default_value_for(result, :pipeline)
+        fill_current_value_with_default_for(result, :global)
+        fill_current_value_with_default_for(result, :pipeline)
+        populate_current_value_for(result, :global)
+        populate_current_value_for(result, :pipeline)
+
+        fill_current_value_with_default_for_analyzers(result)
+        populate_current_value_for_analyzers(result)
+
+        result
+      end
+
+      private
+
+      def sast_template_content
+        Gitlab::Template::GitlabCiYmlTemplate.find('SAST').content
+      end
+
+      def populate_default_value_for(config, level)
+        set_each(config[level], key: :default_value, with: sast_template_attributes)
+      end
+
+      def populate_current_value_for(config, level)
+        set_each(config[level], key: :value, with: gitlab_ci_yml_attributes)
+      end
+
+      def fill_current_value_with_default_for(config, level)
+        set_each(config[level], key: :value, with: sast_template_attributes)
+      end
+
+      def set_each(config_attributes, key:, with:)
+        config_attributes.each do |entity|
+          entity[key] = with[entity[:field]] if with[entity[:field]]
+        end
+      end
+
+      def fill_current_value_with_default_for_analyzers(result)
+        result[:analyzers].each do |analyzer|
+          analyzer[:variables].each do |entity|
+            entity[:value] = entity[:default_value] if entity[:default_value]
+          end
+        end
+      end
+
+      def populate_current_value_for_analyzers(result)
+        result[:analyzers].each do |analyzer|
+          analyzer[:enabled] = analyzer_enabled?(analyzer[:name])
+          populate_current_value_for(analyzer, :variables)
+        end
+      end
+
+      def analyzer_enabled?(analyzer_name)
+        # Unless explicitly listed in the excluded analyzers, consider it enabled
+        sast_excluded_analyzers.exclude?(analyzer_name)
+      end
+
+      def sast_excluded_analyzers
+        strong_memoize(:sast_excluded_analyzers) do
+          all_analyzers = Security::CiConfiguration::SastBuildActions::SAST_DEFAULT_ANALYZERS.split(', ') rescue []
+          enabled_analyzers = sast_default_analyzers.split(',').map(&:strip) rescue []
+
+          excluded_analyzers = gitlab_ci_yml_attributes["SAST_EXCLUDED_ANALYZERS"] || sast_template_attributes["SAST_EXCLUDED_ANALYZERS"]
+          excluded_analyzers = excluded_analyzers.split(',').map(&:strip) rescue []
+          ((all_analyzers - enabled_analyzers) + excluded_analyzers).uniq
+        end
+      end
+
+      def sast_default_analyzers
+        @sast_default_analyzers ||= gitlab_ci_yml_attributes["SAST_DEFAULT_ANALYZERS"] || sast_template_attributes["SAST_DEFAULT_ANALYZERS"]
+      end
+
+      def sast_template_attributes
+        @sast_template_attributes ||= build_sast_attributes(sast_template_content)
+      end
+
+      def gitlab_ci_yml_attributes
+        @gitlab_ci_yml_attributes ||= begin
+          config_content = @project.repository.blob_data_at(@project.repository.root_ref_sha, ci_config_file)
+          return {} unless config_content
+
+          build_sast_attributes(config_content)
+        end
+      end
+
+      def ci_config_file
+        '.gitlab-ci.yml'
+      end
+
+      def build_sast_attributes(content)
+        options = { project: @project, user: current_user, sha: @project.repository.commit.sha }
+        yaml_result = Gitlab::Ci::YamlProcessor.new(content, options).execute
+        return {} unless yaml_result.valid?
+
+        sast_attributes = yaml_result.build_attributes(:sast)
+        extract_required_attributes(sast_attributes)
+      end
+
+      def extract_required_attributes(attributes)
+        result = {}
+        attributes[:yaml_variables].each do |variable|
+          result[variable[:key]] = variable[:value]
+        end
+
+        result[:stage] = attributes[:stage]
+        result.with_indifferent_access
+      end
+    end
+  end
+end