About GitHub-hosted runners
A GitHub-hosted runner is a virtual machine hosted by GitHub with the GitHub Actions runner application installed. GitHub offers runners with Linux, Windows, and macOS operating systems.
When you use a GitHub-hosted runner, machine maintenance and upgrades are taken care of for you. You can run workflows directly on the virtual machine or in a Docker container.
You can specify the runner type for each job in a workflow. Each job in a workflow executes in a fresh instance of the virtual machine. All steps in the job execute in the same instance of the virtual machine, allowing the actions in that job to share information using the filesystem.
The GitHub Actions runner application is open source. You can contribute and file issues in the runner repository.
Cloud hosts for GitHub-hosted runners
GitHub hosts Linux and Windows runners on Standard_DS2_v2 virtual machines in Microsoft Azure with the GitHub Actions runner application installed. The GitHub-hosted runner application is a fork of the Azure Pipelines Agent. Inbound ICMP packets are blocked for all Azure virtual machines, so ping or traceroute commands might not work. For more information about the Standard_DS2_v2 machine resources, see "Dv2 and DSv2-series" in the Microsoft Azure documentation.
GitHub hosts macOS runners in GitHub's own macOS Cloud.
Workflow continuity for GitHub-hosted runners
If GitHub Actions services are temporarily unavailable, then a workflow run is discarded if it has not been queued within 30 minutes of being triggered. For example, if a workflow is triggered and the GitHub Actions services are unavailable for 31 minutes or longer, then the workflow run will not be processed.
In addition, if the workflow run has been successfully queued, but has not been processed by a GitHub-hosted runner within 45 minutes, then the queued workflow run is discarded.
Administrative privileges of GitHub-hosted runners
The Linux and macOS virtual machines both run using passwordless sudo. When you need to execute commands or install tools that require more privileges than the current user, you can use sudo without needing to provide a password. For more information, see the "Sudo Manual."
Windows virtual machines are configured to run as administrators with User Account Control (UAC) disabled. For more information, see "How User Account Control works" in the Windows documentation.
Supported runners and hardware resources
Hardware specification for Windows and Linux virtual machines:
- 2-core CPU
- 7 GB of RAM memory
- 14 GB of SSD disk space
Hardware specification for macOS virtual machines:
- 3-core CPU
- 14 GB of RAM memory
- 14 GB of SSD disk space
| Virtual environment | YAML workflow label | Notes |
|---|---|---|
| Windows Server 2022 | windows-latest or windows-2022 |
The windows-latest label currently uses the Windows Server 2022 runner image.
|
| Windows Server 2019 | windows-2019 |
|
| Ubuntu 20.04 | ubuntu-latest or ubuntu-20.04 |
|
| Ubuntu 18.04 | ubuntu-18.04 |
|
| macOS Big Sur 11 | macos-latest or macos-11 |
The macos-latest label currently uses the macOS 11 runner image.
|
| macOS Catalina 10.15 | macos-10.15 |
Note: The -latest virtual environments are the latest stable images that GitHub provides, and might not be the most recent version of the operating system available from the operating system vendor.
Note: Beta and Deprecated Images are provided "as-is", "with all faults" and "as available" and are excluded from the service level agreement and warranty. Beta Images may not be covered by customer support.
Workflow logs list the runner used to run a job. For more information, see "Viewing workflow run history."
Supported software
The software tools included in GitHub-hosted runners are updated weekly. The update process takes several days, and the list of preinstalled software on the main branch is updated after the whole deployment ends.
Preinstalled software
Workflow logs include a link to the preinstalled tools on the exact runner. To find this information in the workflow log, expand the Set up job section. Under that section, expand the Virtual Environment section. The link following Included Software will describe the preinstalled tools on the runner that ran the workflow.
For more information, see "Viewing workflow run history."
For the overall list of included tools for each runner operating system, see the links below:
GitHub-hosted runners include the operating system's default built-in tools, in addition to the packages listed in the above references. For example, Ubuntu and macOS runners include grep, find, and which, among other default tools.
Using preinstalled software
We recommend using actions to interact with the software installed on runners. This approach has several benefits:
- Usually, actions provide more flexible functionality like versions selection, ability to pass arguments, and parameters
- It ensures the tool versions used in your workflow will remain the same regardless of software updates
If there is a tool that you'd like to request, please open an issue at actions/virtual-environments. This repository also contains announcements about all major software updates on runners.
Installing additional software
You can install additional software on GitHub-hosted runners. For more information, see "Customizing GitHub-hosted runners".
IP addresses
Note: If you use an IP address allow list for your GitHub organization or enterprise account, you cannot use GitHub-hosted runners and must instead use self-hosted runners. For more information, see "About self-hosted runners."
To get a list of IP address ranges that GitHub Actions uses for GitHub-hosted runners, you can use the GitHub REST API. For more information, see the actions key in the response of the "Get GitHub meta information" endpoint.
Windows and Ubuntu runners are hosted in Azure and subsequently have the same IP address ranges as the Azure datacenters. macOS runners are hosted in GitHub's own macOS cloud.
Since there are so many IP address ranges for GitHub-hosted runners, we do not recommend that you use these as allow-lists for your internal resources.
The list of GitHub Actions IP addresses returned by the API is updated once a week.
File systems
GitHub executes actions and shell commands in specific directories on the virtual machine. The file paths on virtual machines are not static. Use the environment variables GitHub provides to construct file paths for the home, workspace, and workflow directories.
| Directory | Environment variable | Description |
|---|---|---|
home | HOME | Contains user-related data. For example, this directory could contain credentials from a login attempt. |
workspace | GITHUB_WORKSPACE | Actions and shell commands execute in this directory. An action can modify the contents of this directory, which subsequent actions can access. |
workflow/event.json | GITHUB_EVENT_PATH | The POST payload of the webhook event that triggered the workflow. GitHub rewrites this each time an action executes to isolate file content between actions. |
For a list of the environment variables GitHub creates for each workflow, see "Using environment variables."
Docker container filesystem
Actions that run in Docker containers have static directories under the /github path. However, we strongly recommend using the default environment variables to construct file paths in Docker containers.
GitHub reserves the /github path prefix and creates three directories for actions.
/github/home/github/workspace- Note: GitHub Actions must be run by the default Docker user (root). Ensure your Dockerfile does not set theUSERinstruction, otherwise you will not be able to accessGITHUB_WORKSPACE./github/workflow