Scheduling a Build

Vela supports the ability to periodically trigger builds for a repo known as a “schedule”.

Outside of the Vela ecosystem, this is more commonly known as a cron expression.

Users will be able to manage schedules for a repo via the UI, API and CLI.

Only users with admin access to a repo will be able to manage schedules for that repo.

Entry

Users will be able to customize the cadence or frequency for how often the schedule should trigger a build via the entry field.

By default, Vela sets a frequency limit of 1h which controls the smallest amount of time a schedule can wait before running.

i.e. A schedule can’t trigger a build more often than every hour but this may be different for the Vela installation you use.

Here’s a small list of examples to demonstrate valid values for this field:

• 0 * * * * - setup a schedule to run every hour
• 0 0 * * * - setup a schedule to run every day at midnight
• 0 0 * * 0 - setup a schedule to run every week on Sunday at midnight

Vela currently uses github.com/adhocore/gronx to parse and validate this field.

This library also supports a number of “common cron expressions” (a.k.a. “tags”) i.e. @hourly, @daily, @weekly etc.

For more information, please see that library’s official docs for these tags.

Pipeline

Uses will be able to customize what stages or steps will run in a build for a schedule using a ruleset:

version: "1"

steps:
  - name: unit-test
    ruleset:
      event: [ deployment, schedule ]
      target: [ unit_test, integration_test, nightly ]
    commands:
      - echo "I run when a schedule with the name 'unit_test', 'integration_test' or 'nightly' is executed"

  - name: integration-test
    ruleset:
      event: [ deployment, schedule ]
      target: [ integration_test, nightly ]
    commands:
      - echo "I run when a schedule with the name 'integration_test' or 'nightly' is executed"
      
  - name: publish
    ruleset:
      event: [ deployment, schedule ]
      target: [ nightly ]
    commands:
      - echo "I run when a schedule with the name 'nightly' is executed"
      
  - name: notification
    ruleset:
      event: [ deployment, schedule ]
    commands:
      - echo "I run when any schedule is executed"