Stages

Note

This feature is experimental and currently only available when using use_unstable_cli option in the GitHub Action or using the stages feature when compiling.

This property will allow users to define a list of Containerfile stages each with their own modules. Stages can be used to compile programs, perform parallel operations, and copy the results into the final image without contaminating the final image.

Module Support

Currently the only modules that work out-of-the-box are copy, script, files, and containerfile. Other modules are dependent on the programs installed on the image. In order to better support some of our essential modules, a setup script is ran at the start of each stage that is not scratch. This script will install curl, wget, bash, and grep and use the package manager for the detected distributions.

At this time, the following distributions are supported:

• Debian
• Ubuntu
• Fedora
• Alpine

Other distributions can be used, but the necessary packages won’t be installed automatically. Contributions to increase the size of this list is welcome!

Syntax

from:

The full image ref (image name + tag). This will be set in the FROM statement of the stage.

name:

The name of the stage. This is used when referencing the stage when using the from: property in the copy module.

modules:

The list of modules to execute. The exact same syntax used by the main recipe modules: property.

shell: (optional)

Allows a user to pass in an array of strings that are passed directly into the SHELL instruction.

Example

name: custom-image
base-image: ghcr.io/ublue-os/silverblue-main
image-version: 40
description: Stages example
stages:
  - name: helix
    from: docker.io/library/rust
    modules:
      - type: script
        snippets:
          - apt-get update && apt-get install -y git # Install git
          - git clone https://github.com/helix-editor/helix.git # Clone the helix repo
          - cd helix && RUSTFLAGS="-C target-feature=-crt-static" cargo install --path helix-term # Use cargo to install
          - mkdir -p /out/ && mv $CARGO_HOME/bin/hx /out/hx && mv runtime /out/ # Move bin and runtime
modules:
  # Copy the bin and runtime from the `helix` stage
  - type: copy
    from: helix
    src: /out/hx
    dest: /usr/bin/
  - type: copy
    from: helix
    src: /out/runtime
    dest: /usr/lib64/helix/