Running jobs in a container

Overview

Use jobs.<job_id>.container to create a container to run any steps in a job that don't already specify a container. If you have steps that use both script and container actions, the container actions will run as sibling containers on the same network with the same volume mounts.

If you do not set a container, all steps will run directly on the host specified by runs-on unless a step refers to an action configured to run in a container.

Example: Running a job within a container

name: CI
on:
  push:
    branches: [ main ]
jobs:
  container-test-job:
    runs-on: ubuntu-latest
    container:
      image: node:14.16
      env:
        NODE_ENV: development
      ports:
        - 80
      volumes:
        - my_docker_volume:/volume_mount
      options: --cpus 1
    steps:
      - name: Check for dockerenv file
        run: (ls /.dockerenv && echo Found dockerenv) || (echo No dockerenv)

When you only specify a container image, you can omit the image keyword.

jobs:
  container-test-job:
    runs-on: ubuntu-latest
    container: node:14.16

Defining the container image

Use jobs.<job_id>.container.image to define the Docker image to use as the container to run the action. The value can be the Docker Hub image name or a registry name.

Defining credentials for a container registry

If the image's container registry requires authentication to pull the image, you can use jobs.<job_id>.container.credentials to set a map of the username and password. The credentials are the same values that you would provide to the docker login command.

Example: Defining credentials for a container registry

container:
  image: ghcr.io/owner/image
  credentials:
     username: ${{ github.actor }}
     password: ${{ secrets.github_token }}

Using environment variables with a container

Use jobs.<job_id>.container.env to set a map of environment variables in the container.

Exposing network ports on a container

Use jobs.<job_id>.container.ports to set an array of ports to expose on the container.

Mounting volumes in a container

Use jobs.<job_id>.container.volumes to set an array of volumes for the container to use. You can use volumes to share data between services or other steps in a job. You can specify named Docker volumes, anonymous Docker volumes, or bind mounts on the host.

To specify a volume, you specify the source and destination path:

<source>:<destinationPath>.

The <source> is a volume name or an absolute path on the host machine, and <destinationPath> is an absolute path in the container.

Example: Mounting volumes in a container

volumes:
  - my_docker_volume:/volume_mount
  - /data/my_data
  - /source/directory:/destination/directory

Setting container resource options

Use jobs.<job_id>.container.options to configure additional Docker container resource options. For a list of options, see "docker create options."