Choosing the execution environment for a job¶

Define the type of execution environment that will process a job in your workflow.

Overview¶

Use jobs.<job_id>.runs-on to define the type of execution environment to run the job on.

The destination environment can be either a SSH-hosted execution environment, an agent-based execution environment, or an operator-based dynamic execution environment.
You can provide runs-on as:
- A single string
- A single variable containing a string
- An array of strings, variables containing strings, or a combination of both
If you specify an array of strings or variables, your workflow will execute on any execution environment that matches all of the specified runs-on values. For example, here the job will only run on an execution environment that has the tags linux, x64, and gpu:
```
runs-on: [linux, x64, gpu]
```

You can mix strings and variables in an array. For example:

variables:
  CHOSEN_OS: linux
jobs:
  test:
    runs-on: [robotframework, "${{ variables.CHOSEN_OS }}"]
    steps:
    - run: echo Hello world!

Note

Quotation marks are not required around simple strings like robotframework, but they are required for expressions like ${{ variables.CHOSEN_OS }}.

Choosing the execution environment¶

To specify an execution environment for your job, configure runs-on in your workflow file with execution environment tags.

Execution environments have an operating system tag (linux, macos, or windows). They may have other tags.

Tags can be used to create targeting options for execution environments, such as operating system or architecture. We recommend providing an array of tags that begins with the operating system tag and then includes additional tags as needed. When you specify an array of tags, job will be queued on execution environments that have all the tags that you specify.

Example: Specifying an operating system

runs-on: linux

Example: Using tags for execution environment selection

runs-on: [linux, x64, gpu]