module Gitlab module Middleware class ReadOnly DISALLOWED_METHODS = %w(POST PATCH PUT DELETE).freeze APPLICATION_JSON = 'application/json'.freeze API_VERSIONS = (3..4) def initialize(app) @app = app @whitelisted = internal_routes end def call(env) @env = env @route_hash = nil if disallowed_request? && Gitlab::Database.read_only? Rails.logger.debug('GitLab ReadOnly: preventing possible non read-only operation') error_message = 'You cannot do writing operations on a read-only GitLab instance' if json_request? return [403, { 'Content-Type' => 'application/json' }, [{ 'message' => error_message }.to_json]] else rack_flash.alert = error_message rack_session['flash'] = rack_flash.to_session_value return [301, { 'Location' => last_visited_url }, []] end end @app.call(env) end private def internal_routes API_VERSIONS.flat_map { |version| "api/v#{version}/internal" } end def disallowed_request? DISALLOWED_METHODS.include?(@env['REQUEST_METHOD']) && !whitelisted_routes end def json_request? request.media_type == APPLICATION_JSON end def rack_flash @rack_flash ||= ActionDispatch::Flash::FlashHash.from_session_value(rack_session) end def rack_session @env['rack.session'] end def request @env['rack.request'] ||= Rack::Request.new(@env) end def last_visited_url @env['HTTP_REFERER'] || rack_session['user_return_to'] || Rails.application.routes.url_helpers.root_url end def route_hash @route_hash ||= Rails.application.routes.recognize_path(request.url, { method: request.request_method }) rescue {} end def whitelisted_routes grack_route || @whitelisted.any? { |path| request.path.include?(path) } || lfs_route || sidekiq_route end def sidekiq_route request.path.start_with?('/admin/sidekiq') end def grack_route route_hash[:controller] == 'projects/git_http' && route_hash[:action] == 'git_upload_pack' end def lfs_route route_hash[:controller] == 'projects/lfs_api' && route_hash[:action] == 'batch' end end end end