v1.11.3

Changes

• reminder_message now obeys annotate_messages
• reminder_message templates now have access to two variables:
  • on_secs (float) is number of seconds the alert has been on.
  • on_time_str is length of time alert has been on as a string.
    Default message for reminder_message is
    on for {{ on_time_str }}
• Add boolean attribute is_acked to alert entities to simplify determining if alert has been acked or not.