Linux runners - RunsOn

RunsOn supports both native x64 and arm64 Linux runners.

Flex

Pick a predefined runner from the runs-on label — 2cpu-linux-x64 for x64, 2cpu-linux-arm64 for arm64:

jobs:
  build:
    runs-on: runs-on=${{ github.run_id }}/runner=2cpu-linux-x64
    steps:
      - uses: runs-on/action@v2
      - run: echo "Hello from x64!"

jobs:
  build:
    runs-on: runs-on=${{ github.run_id }}/runner=2cpu-linux-arm64
    steps:
      - uses: runs-on/action@v2
      - run: echo "Hello from arm64!"

Most users go beyond the predefined names and tailor CPU, memory, family, and volume with job labels or custom runners.

Fleet

Define the runner shape in Terraform, publish it as a fleet, then target the fleet from workflow YAML:

runners = {
  linux-small = {
    family = ["c8i.large"]
    image  = "ubuntu24-full-x64"
  }
}

fleets = {
  linux-small = {
    runner = "linux-small"
  }
}

jobs:
  build:
    runs-on: runs-on/fleet=linux-small/env=production

Default images#

Opt into a specific image with the image label. When you set image, make sure your family uses instance types matching the image architecture (e.g. family=c8g+m8g for arm64).

Image	Architecture	Description
`ubuntu22-full-x64`	x64	Compatible with the official Ubuntu 22.04 GitHub runner image.
`ubuntu24-full-x64`	x64	Compatible with the official Ubuntu 24.04 GitHub runner image.
`ubuntu26-full-x64`	x64	Compatible with the official Ubuntu 26.04 GitHub runner image.
`ubuntu22-full-arm64`	arm64	Compatible with the official Ubuntu 22.04 GitHub runner image.
`ubuntu24-full-arm64`	arm64	Compatible with the official Ubuntu 24.04 GitHub runner image.
`ubuntu26-full-arm64`	arm64	Compatible with the official Ubuntu 26.04 GitHub runner image.

Examples#

Disable spot pricing for critical jobs:

jobs:
  build:
    runs-on: runs-on=${{ github.run_id }}/runner=2cpu-linux-x64/spot=false

Only allow 4-CPU instances from compute-optimized families:

jobs:
  build:
    runs-on: runs-on=${{ github.run_id }}/runner=4cpu-linux-x64/family=c8

Fully custom definition — launched in a private subnet with a static egress IP:

jobs:
  build:
    runs-on: runs-on=${{ github.run_id }}/ram=8/family=m8+c8+r8/image=ubuntu24-full-x64/spot=false/ssh=false/private=true

Need help choosing? Use the instance finder ↗ to match AWS instances to your CPU, RAM, and architecture requirements.

Quotas#

New AWS accounts have low default quotas for standard instances, so you may need an increase to launch many jobs.

How to request an increase

Search for “Quotas” in the AWS console.
Click “Request quota increase”.
Select “EC2” as the service.
Select the standard instance type.
Fill in the form and submit (you request vCPUs, not instance count).
Repeat for both spot and on-demand quotas.