Global Variables Reference

Complete reference for global configuration in images/variables.yml

Complete reference for global configuration settings that apply to all container images.

Overview

The images/variables.yml file contains global configuration that applies to all container images in the repository. These settings define project-wide defaults, security parameters, and variant-specific behavior.

Location: images/variables.yml (in the containers repository root)

Scope: All images inherit these settings unless overridden in image-specific properties.yml

Configuration Reference

cpe

  • Type: String (CPE 2.2 formatted string)
  • Default: "cpe:/a:redhat:hummingbird:1"
  • Description: Common Platform Enumeration (CPE) identifier for all Hummingbird containers.
  • Usage: Automatically added as a label to all generated container images and passed to inject-source-info during the build process.
  • Format: CPE 2.2 URI format: cpe:/part:vendor:product:version

default_user

  • Type: String (numeric UID)
  • Default: "65532"
  • Description: The default unprivileged user ID that all containers run as.
  • Usage: Referenced by the {{ set_user() }} macro when user: default is specified (or when user: is omitted, as default is the default value).
  • Value: 65532 is chosen as a high, non-conflicting UID that:
    • Avoids conflicts with system users (typically < 1000)
    • Avoids conflicts with regular users (typically 1000-60000)

default_distros

  • Type: Array of strings
  • Default: ["rawhide", "hummingbird"]
  • Description: Defines the distribution variants (distros) for which images are built. Each distro represents a different base package source.
  • Directory Structure: Images are organized as images/<name>/<distro>/<variant>/
  • Common Values:
    • rawhide - Uses Fedora Rawhide repositories only
    • hummingbird - Uses both Fedora Rawhide and Hummingbird repositories
  • Usage: Scripts iterate over distros and variants to find all image variants to build. Each distro/variant combination produces a separate container image.
  • See Also: default_variant_repos for repository configuration per distro

default_variants

  • Type: Array of strings
  • Default: ["default", "builder"]
  • Description: Defines the default set of variants to generate for each image within each distro when not explicitly specified in the image’s properties.yml.
  • Directory Structure: Variants are subdirectories within each distro: images/<name>/<distro>/<variant>/
  • Common Values:
    • default - The minimal runtime variant
    • builder - Extended variant with build tools and package managers
  • Extending: Images can use additional_variants in properties.yml to add extra variants while keeping the defaults (preferred approach)
  • Override: Images can specify variants in properties.yml to replace these defaults entirely (use when you need to exclude default variants)
  • See Also: Image Configuration Reference - variants

default_rpm_packages

  • Type: Object with variant names as keys, arrays of package names as values

  • Default:

    default_rpm_packages:
  builder:
    - bash
    - dnf5
    - shadow-utils

  • Description: Defines packages that are automatically included in specific variants across all images. These are added in addition to packages defined in image-specific properties.yml.

  • Variants: Currently only builder is defined, but other variants can be added

  • Usage: Use this to provide variant-specific packages that should be available in all images using that variant. For example, builder variants include package management tools for development workflows.

default_variant_repos

  • Type: Object with distro names as keys, arrays of repository filenames as values

  • Default:

    default_variant_repos:
  rawhide:
    - fedora-44.repo
  hummingbird:
    - fedora-43.repo
    - hummingbird.repo

  • Description: Defines which yum repositories each distro uses by default for package installation and lockfile generation. The Rawhide distro uses the latest branched Fedora development repo, while Hummingbird uses a stable Fedora release plus the Hummingbird package repository.

  • Repository Files: References files in the yum-repos/ directory

  • Usage: This allows different distros to use different package sources. The hummingbird distro includes additional repositories that provide Hummingbird-specific packages.

  • Override: Image-specific additional_repos in properties.yml are appended to the distro-specific repos

  • See Also: Image Configuration Reference - additional_repos

readme_targets

  • Type: Object with target names as keys, configuration objects as values

  • Default: See the actual file

  • Description: Defines target-specific configuration for generating multiple README files from a single template. Each target represents a different build/distribution channel (e.g., Hummingbird project vs Red Hat product).

  • Target Configuration Fields:

    • filename - Output filename for this target’s README
    • registry - Container registry URL for image references
    • product_name - Full product name for documentation
    • product_name_short - Short product name for headings and titles
    • doc_base_url - Base URL for documentation links

  • Usage: Templates access these values via {{ readme_targets[target].registry }} and similar expressions. The build system generates one README file per target from the same README.md.j2 template.

  • See Also: Image Pipeline - README Generation

Next Steps