lex-scheduler

Cron and interval task scheduling for LegionIO. Reads schedule definitions from the database, determines which tasks are due, and publishes them to the message bus. Uses a distributed lock via legion-cache to ensure only one node runs the scheduler at a time.

This is a core LEX required for scheduled task execution.

Installation

gem install lex-scheduler

Usage

Schedules are stored in the database with either a cron expression or an interval:

• Interval: Run every N seconds since the last completion (integer)
• Cron: Run at specific times using standard cron syntax (*/5 * * * *) or human-readable expressions (every day at noon) parsed by fugit

Schedules can also carry a transformation ERB template. If present, the scheduled task is routed through lex-transformer before execution.

Adding Schedules

Insert records into the schedules table via legion-data:

Legion::Extensions::Scheduler::Data::Models::Schedule.insert(
  function_id: 42,
  interval:    300,          # run every 5 minutes
  active:      1,
  last_run:    Time.now,
  payload:     '{}'
)

Standalone Client

Legion::Extensions::Scheduler::Client provides access to the Schedule runner:

require 'legion/extensions/scheduler/client'
client = Legion::Extensions::Scheduler::Client.new

Accepts optional data_model: and fugit: kwargs for injection (useful in tests).

Requirements

• Ruby >= 3.4
• LegionIO framework
• legion-data (schedule persistence)
• legion-cache (distributed scheduler lock)
• fugit >= 1.9 (cron expression parsing)

License

MIT