Apko on

apko Overview

Mon, 10 Oct 2022 11:07:52 +0200

apko is a command-line tool designed to create single-layer container images based on the apk package format. It was so named as it uses the apk package format and is inspired by the ko build tool.

apko is part of the open source toolkit developed by Chainguard to build Chainguard Containers. The following diagram contains an overview of the apko ecosystem and how it interacts with melange for building apk-based images, using either Wolfi or Alpine as base system.

apko FAQs

Mon, 10 Oct 2022 11:07:52 +0200

Do I need to understand apko to use Chainguard Containers?

No. Chainguard built apko as part of its open source tooling around the Wolfi operating system. While you can check out the project on GitHub and learn more, it’s not a prerequisite for using Chainguard Containers.

Getting Started with apko

Wed, 06 Jul 2022 08:49:31 +0000

apko is a command-line tool to build container images using a declarative language based on YAML. apko is so named as it uses the apk package format and is inspired by the ko build tool. It is part of the open source tooling Chainguard developed to create the Wolfi operating system which is used in Chainguard Containers.

Why apko

Container images are typically assembled in multiple steps. A tool like Docker, for example, combines building steps (as in, running commands to copy files, build and deploy applications) and composition (as in, composing a base image with pre-built packages) in a single piece of software. apko, on the other hand, is solely a composition tool that focuses on producing lightweight, “flat” base images that are fully reproducible and contain auto generated SBOM files for every successful build.

Troubleshooting apko Builds

Wed, 10 Aug 2022 11:07:52 +0200

Debug Options

To include debug-level information on apko builds, add --debug to your build command:

Why apk

Wed, 06 Jul 2022 08:49:31 +0000

apko uses the apk package manager to compose container images based on declarative pipelines. The apk format was introduced by Alpine Linux to address specific design requirements that could not be met by existing package managers such as apt and dnf. But what makes it different, and why does that matter in the context of apko?

Manipulating the Desired State

In traditional package managers like dnf and apt, requesting the installation or removal of packages causes those packages to be directly installed or removed, after a consistency check.

Bazel Rules for apko

Mon, 23 Oct 2023 08:49:31 +0000

rules_apko is an open source plugin for Bazel that makes it possible to build secure, minimal Wolfi-based container images using the Bazel build system. It wraps the apko tool for use under Bazel, providing hermetic, reproducible image builds with full Bazel caching support.

By the end of this guide you will have a working Bazel project that builds a minimal Wolfi-based container image using rules_apko.

How to build a container with Bazel using `rules_apko`

This page covers rules_apko version 1.5.37 with Bazel 9.0.1 using Bzlmod, which is the only supported dependency management method in Bazel 9. If you are on an earlier version of Bazel, you should upgrade to Bazel 9 before following this guide.