Documentation structure for LLMs (llms.txt)
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Using the Linux VM execution environment

9 hours ago
Cloud Server

Using the machine executor gives your application full access to OS resources and provides you with full control over the job environment. This control can be useful when you need full access to the network stack. For example, you can listen on a network interface or change the system with sysctl commands.

To use the machine executor, use the machine key in your job configuration and specify an image:

  • Cloud

  • Server

version: 2.1
jobs:
  my-job:
    machine:
      image: ubuntu-2604:current
    resource_class: large.gen2
version: 2.1
jobs:
  my-job:
    machine:
      image: default
    resource_class: large

Your system administrator manages the available Linux images.

On CircleCI Server, machine: true also works as shorthand for machine with image: default.

Available LinuxVM resource classes

Gen1

Class vCPUs RAM Disk Size Cloud Server

medium

2

7.5 GB

150GB

Yes

Yes

large

4

15 GB

150GB

Yes

Yes

xlarge

8

32 GB

150GB

Yes

Yes

2xlarge

16

64 GB

150GB

Yes

Yes

2xlarge+

32

64 GB

150GB

Yes

Yes

View resource usage

To view the compute resource usage for the duration of a job in the CircleCI web app:

  1. In the CircleCI web app, select your org from the org cards on your user homepage.

  2. Select Pipelines from the sidebar and locate your pipeline from the list. You can use the project, branch, date, and status search options to help.

  3. Select the job you want to access by selecting the job name.

  4. Select the Resources tab to view CPU and RAM usage for the duration of the job.

You can use these insights to decide whether to make changes to the job’s configured resource class.

Resources tab
Figure 1. Resources tab in web app for a job

Pre-installed software

You can find the most up-to-date list of pre-installed software on the Discuss page.

If you are already using an image, you can verify all the packages that come pre-installed. Run the apt list --installed command as a step, like in the example below:

version: 2.1
...
jobs:
  whats-installed:
    machine: # executor type
      image: default
    steps:
      - run: apt list --installed
...

You can install additional packages with sudo apt-get install <package>. If the package is not found, run sudo apt-get update before installing it.

Use machine with Docker

Using the machine executor also means that you get full access to the Docker process. This allows you to run privileged Docker containers and build Docker images.

The following example uses an image and enables Docker Layer Caching (DLC) which is useful when you are building Docker images during your jobs.

machine:
  image: default
  docker_layer_caching: true    # default - false

Next steps

To find out about migrating a project from using the Docker executor to using machine, see the Executor Migration from Docker to Machine document.