module Gitlab module Middleware class ReadonlyGeo DISALLOWED_METHODS = %w(POST PATCH PUT DELETE) APPLICATION_JSON = 'application/json' API_VERSIONS = (3..4) def initialize(app) @app = app @whitelisted = internal_routes + geo_routes end def call(env) @env = env if disallowed_request? && Gitlab::Geo.secondary? Rails.logger.debug('GitLab Geo: preventing possible non readonly operation') error_message = 'You cannot do writing operations on a secondary GitLab Geo 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 geo_routes geo_routes = ['refresh_wikis', 'receive_events'] API_VERSIONS.flat_map { |version| geo_routes.map { |route| "api/v#{version}/geo/#{route}" } } 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 @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 logout_route || grack_route || @whitelisted.any? { |path| request.path.include?(path) } || sidekiq_route end def logout_route route_hash[:controller] == 'sessions' && route_hash[:action] == 'destroy' end def sidekiq_route @request.path.start_with?('/admin/sidekiq') end def grack_route @request.path.end_with?('.git/git-upload-pack') end end end end