Git Image Source Setup

Cloud Builder reads any information about a KIWI image and its metadata from a specified git repository. This includes the following types of information:

The image configuration files:

These are all files to build a KIWI image. For details see: https://osinside.github.io/kiwi/overview.html

The .cb/cloud_builder.yml project file:

This file contains information for Cloud Builder to know how the image should be build. It also contains information about the runner group that is eligible to pick up the build request.

Before creating the git repository, let’s clone the example cloud-builder-packages git repo from here:

git clone https://github.com/OSInside/cloud-builder-packages.git

Understanding the project structure

By convention the Cloud Builder package sources need to follow a certain files/directory structure which is provided in the reference git clone from above. In general the project structure is aligned to the following layout:

projects
├── ...
│
├── PROJECT_A
│   └── SUB_PROJECT
│       └── ...
│
└── images
    └── leap
        └── test-image-disk
            ├── .cb
            │    └── cloud_builder.yml
            ├── appliance.kiwi
            └── config.sh

Note

It’s important that all projects are stored below a directory called projects. This is the only convention Cloud Builder expects to be respected. Below projects any custom structure to store projects and image sources is allowed

Understanding .cb/cloud_builder.yml

In general .cb/cloud_builder.yml contains information about how the image target should be build. A typical file looks like the following:

schema_version: 0.1
name: test-image-disk

images:
  -
    arch: x86_64
    runner_group: suse
    selection:
      name: standard
      profiles:
        - A
        - B
      build_arguments:
        - "--clear-cache"

schema_version:

Cloud Builder validates any information send through the message broker and read by services via a Cerberus validated schema. Every schema comes with a version such that changes to the schema in the future becomes possible.

name:

Specifies the name of the image project. It’s advisable to use the same name as used in the KIWI image desription. When Cloud Builder builds the image, the output filenames are the result of the KIWI image build and not connected to the name used here.

images:

Contains the target information for images to build from the KIWI image description. The settings here allows to build the image with custom options, e.g for different profiles, call options or architectures.

• arch:

  An architecture name. The name must match one of the names known to Python’s platform.machine() names.

• runner_group:

  The runner group specifies a name that matches with the runner_group setup on the runner instance. A request to build the image will only be taken by runners of that group. That way an image for e.g a specific architecture can be connected to a runner which is of that architecture.

• selection:

  The selection is a name for a collection of KIWI build parameters and provides a namespace to group this information.

  • name:

    Name of the selection

  • profiles:

    List of KIWI profile names to use for building the image

  • build_arguments:

    List of KIWI caller arguments to pass in addition to the ones set by default

Note

With the explanation on the git contents based on the example cloud-builder-packages repo, the next step could be to create the project specific git repo and place the desired image and metadata source files. It would also be possible to continue with the example git repo and move to the real sources later.

Learn how to setup the message broker service Kafka Message Broker Setup