module Gitlab module Ci class CronParser VALID_SYNTAX_SAMPLE_TIME_ZONE = 'UTC'.freeze VALID_SYNTAX_SAMPLE_CRON = '* * * * *'.freeze def initialize(cron, cron_timezone = 'UTC') @cron = cron @cron_timezone = timezone_name(cron_timezone) end def next_time_from(time) @cron_line ||= try_parse_cron(@cron, @cron_timezone) @cron_line.next_time(time).utc.in_time_zone(Time.zone) if @cron_line.present? end def cron_valid? try_parse_cron(@cron, VALID_SYNTAX_SAMPLE_TIME_ZONE).present? end def cron_timezone_valid? try_parse_cron(VALID_SYNTAX_SAMPLE_CRON, @cron_timezone).present? end private def timezone_name(timezone) ActiveSupport::TimeZone.find_tzinfo(timezone).name rescue TZInfo::InvalidTimezoneIdentifier timezone end # NOTE: # cron_timezone can only accept timezones listed in TZInfo::Timezone. # Aliases of Timezones from ActiveSupport::TimeZone are NOT accepted, # because Rufus::Scheduler only supports TZInfo::Timezone. # # For example, those codes have the same effect. # Time.zone = 'Pacific Time (US & Canada)' (ActiveSupport::TimeZone) # Time.zone = 'America/Los_Angeles' (TZInfo::Timezone) # # However, try_parse_cron only accepts the latter format. # try_parse_cron('* * * * *', 'Pacific Time (US & Canada)') -> Doesn't work # try_parse_cron('* * * * *', 'America/Los_Angeles') -> Works # If you want to know more, please take a look # https://github.com/rails/rails/blob/master/activesupport/lib/active_support/values/time_zone.rb def try_parse_cron(cron, cron_timezone) cron_line = Rufus::Scheduler.parse("#{cron} #{cron_timezone}") cron_line if cron_line.is_a?(Rufus::Scheduler::CronLine) rescue # noop end end end end