Fix lazy error handling of cron parser

1 files changed, 17 insertions, 2 deletions

diff --git a/lib/gitlab/ci/cron_parser.rb b/lib/gitlab/ci/cron_parser.rb
index a3cc350ef22..dad8c3cdf5b 100644
--- a/lib/gitlab/ci/cron_parser.rb
+++ b/lib/gitlab/ci/cron_parser.rb
@@ -6,7 +6,7 @@ module Gitlab
 
       def initialize(cron, cron_timezone = 'UTC')
         @cron = cron
-        @cron_timezone = cron_timezone
+        @cron_timezone = ActiveSupport::TimeZone.find_tzinfo(cron_timezone).name
       end
 
       def next_time_from(time)
@@ -24,8 +24,23 @@ module Gitlab
 
       private
 
+      # 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)
-        Rufus::Scheduler.parse("#{cron} #{cron_timezone}")
+        cron_line = Rufus::Scheduler.parse("#{cron} #{cron_timezone}")
+        cron_line if cron_line.is_a?(Rufus::Scheduler::CronLine)
       rescue
         # noop
       end