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Idle Runners

Cirun creates runners on-demand on various cloud providers, which takes sometimes a couple of minutes or more. This might not be suitable for use cases where you need to run CI jobs almost instantly like GitHub hosted runners. This is why we introduced the ability to keep "x" number of runners always (or at some specified times) running. This will help you run workflows almost instantly.

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  • Idle runners does not mean that the same machine will be re-used for jobs. Runners are destroyed after the job completes. Idle runner configuration makes sure that given number of runners are always available, as in a runner is created if one of the runners picks up a job.

Specifying idle runners in the .cirun.yml, does not prevent spinning up of on-demand runners, but cirun will try to re-use existing runners where possible.

Examples​

Here are some example of specifying configuration for idle runners in .cirun.yml

Make 4 runners always available from 9 AM - 5 PM on Monday to Friday and 1 on the weekend:​

runners:
  - name: aws-cpu-runner
    cloud: aws
    instance_type: t2.medium
    machine_image: ami-06fd8a495a537da8b
    preemptible: true
    labels:
      - cirun-runner
    idle:
      schedule:
        - day: mon-fri
          time: 9-17
          timezone: UTC
          replicas: 4
        - day: sat-sun
          time: 9-17
          timezone: UTC
          replicas: 1

Make 4 runners always available from 9 AM - 5 PM on Monday to Friday and 0 on weekend:​

runners:
  - name: aws-cpu-runner
    cloud: aws
    instance_type: t2.medium
    machine_image: ami-06fd8a495a537da8b
    preemptible: true
    labels:
      - cirun-runner
    idle:
      schedule:
        - day: mon-fri
          time: 9-17
          timezone: UTC
          replicas: 4

Make variable number of runners available on different days of week:​

runners:
  - name: aws-cpu-runner
    cloud: aws
    instance_type: t2.medium
    machine_image: ami-06fd8a495a537da8b
    preemptible: true
    labels:
      - cirun-runner
    idle:
      schedule:
        - day: mon
          time: 9-17
          timezone: UTC
          replicas: 2
        - day: wed
          time: 9-17
          timezone: UTC
          replicas: 3
        - day: fri
          time: 9-17
          timezone: UTC
          replicas: 4

Schedule Reference​

The schedule key expects a list of objects, below is the reference for the same:

day​

Day(s) of the week, e.g.

  • mon
  • tue
  • wed
  • thu
  • fri
  • sat
  • sun

It could be a single day or a range of days, e.g.

  • mon-wed
  • mon-fri
  • thu-fri
  • sat-sun

time​

Time range of the day in 24-hour format, e.g.

  • 8-17 (8 AM - 5 PM)
  • 0-8 (12 AM - 8 AM)
  • 20-23 (8 PM - 11 PM)

timezone​

Timezone of the schedule. This the TZ identifier from the TZ Database, e.g.

  • UTC
  • Asia/Calcutta
  • US/Eastern
  • US/Central

replicas​

Number of runners to keep idle, expects an integer.