Fast Assembler for Bootc

fab is a somewhat opinionated build pipeline for bootc, allowing the modularization of Containerfiles/bootc image building.

Fabfiles and module definitions

fab is structured as a main descriptive file for the final image, currently called "Fabfile". A Fabfile example looks like this:

---
metadata:
  name: fabrules
  description: My first bootc
from: quay.io/centos-bootc/centos-bootc:stream9
include:
  - modules/ssh/ssh.yaml
  - modules/dnf/install.yaml
buildargs:
  - SSHPUBKEY: (...)
  - RPMS: tmux cloud-init

The fields are somewhat self-explanatory:

• metadata: just metadata about the bootc image
• from: base image (i.e. the first FROM in the pipeline)
• include: list of modules to include, in order in the bootc image
• buildargs: list of buildargs (variables) used in the build process

For each module, there is a short descriptive file with the module definition (see modules/ directory for examples):

---
metadata:
  name: dnf-install
  description: |
    Install a list of packages via dnf
containerfile: install.Containerfile
buildargs:
  - RPMS

Like with the top level definition, the fields should be easy to understand:

• metadata: module level metadata
• containerfile: filename for the Containerfile to use
• buildargs: simple list of expected buildargs (without values!)

Installation

$ git clone [email protected]:kwozyman/fab.git
$ cd fab
$ python3 -m pip install --requirement requirements.txt

Usage

A simple python3 -m fab --help will show the full command line arguments.

In order to build the container from Fabfile.example:

$ python3 -m fab build --fabfile Fabfile.example

The above will trigger container image builds in sequence for each of the modules and the final one at the end.

Debugging messages can be enabled in fab with the --log-level debug switch, and in the underlying podman call with the --container-tool-extra-args switch:

$ python3 -m fab --container-tool-extra-args="--log-level debug" --log-level debug  build --fabfile Fabfile.example