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Packaging and Versioning#

This document surveys the various sorts of piles of things that exist in KubeStellar and how they are versioned.

outline of things

The picture above outlines the situation. The thing at the tail of an arrow refers to or in some way consumes from the thing at the head of the arrow. Some details omitted for brevity: the full release archives, the Kubernetes API group, and the space framework component.

Kubernetes API group#

KubeStellar defines a Kubernetes API group, named API groups are versioned; see the Kubernetes documentation on API group versioning. The Kubernetes API of KubeStellar is defined in pkg/apis/edge.

The API objects form the interface between users and the controllers that implement the semantics of those objects.

Two versions of the API group have been defined.

  • v1alpha1, for the Kubernetes API of KubeStellar releases 0.7 and earlier.
  • v2alpha1, for the Kubernetes API of KubeStellar releases 0.8 and later.

Syncer container image#

The syncer is KubeStellar's agent in WECs, and is based on a Kubernetes Pod that uses a container image at This container image is built from contents of the KubeStellar GitHub repo focused by ko on the syncer binary. This image is normally built using the make target named "build-kubestellar-syncer-image. The syncer image is referenced in the output generated by the kubectl kubestellar syncer-gen command, which is invoked by kubectl kubestellar prep-for-syncer, which is invoked by kubectl kubestellar prep-for-cluster. The kubectl kubestellar prep-for-syncer script holds the default value for the tag to use in the reference to the syncer image.

Following are some recent tags and what they correspond to.

  • v0.9.0, for the git commit with that tag (i.e., that release).

  • v0.8.0, for the git commit with that tag (i.e., that release).

  • pr-1103 = git-ae64d5722-clean, incorporating PR 1103, the latest development in the release-0.7 line.

Core container image#

The core container runs the kcp server and the KubeStellar core controllers and initializes the kcp workspaces. It is built from some contents of the KubeStellar GitHub repo, specifically excluding some that are only needed by users outside this container. This image is normally built using the make target "kubestellar-image". This image is referenced from the core Helm chart, which can be used directly from the Helm repo and also is used by the kubectl kubestellar deploy command (which has a fixed image tag in its source, which is edited when it is time to advance that tag).

Following are some recent tags and what they correspond to.

  • release-0.9, for the release 0.9 line of development; currently this points to the same image as v0.9.0 but may move in the future.

  • v0.9.0 = v0.9.0-alpha.1.git1f0e2cc-clean, for the v0.9.0 release.

KubeStellar core Helm chart#

This Helm chart describes a deployment of the KubeStellar core components (kcp server, KubeStellar controllers, initialization) as workload for a Kubernetes cluster.

The source of this Helm chart is in the core-helm-chart subdirectory of the kubestellar GitHub repo.

The kubectl kubestellar deploy command uses the adjacent copy of this Helm chart. That is: (1) in the case of working with a local copy of the kubestellar/kubestellar GitHub repo, the copy in the core-helm-chart directory, and (2) in the case of using an unpacked release archive --- which contains core-helm-chart as well as bin --- that unpacked copy of core-helm-chart.

Alternatively, users can use the Helm repository at, which is served via GitHub pages from the main branch of the kubestellar/helm GitHub repo. This repository holds tar archives of released versions of the chart, created manually from the sources in the core-helm-chart subdirectory of the kubestellar GitHub repo.

A Helm chart has both a version number for the chart itself and a version number for the "application" it installs.

Currently there is only one version of the chart that is interesting.

Chart Version App Version What it is
1/2 (some confusion here) v0.9.0 KubeStellar release-0.9 branch

GitHub repos#


The kubestellar repo is the main repo for KubeStellar. It holds the code and documentation and the source of the Helm chart. The following branches and tags are most interesting.

  • branch main is the main line of development.
  • branch release-0.9 is for development along the line of the 0.9 release.
  • tag v0.9.0 is release 0.9.0.


The helm GitHub repo hosts distributions of archived versions of the chart, as discussed above.


The homebrew-kubestellar GitHub repo serves directly as the homebrew repository for KubeStellar. According to homebrew convention, users refer to it in homebrew as kubestellar/kubestellar (e.g., brew tap kubestellar/kubestellar connects directly to this GitHub repository).

This HomeBrew repository has two formulae. One called kcp_cli has the kubectl plugins of kcp. Release v0.11.0 of kcp is always used. A formula called kubestellar_cli has contents that are needed by a user who deploys the KubeStellar core as workload in a Kubernetes cluster or another user of that deployment. This formula fetches and installs a kubestellaruser release archive from GitHub. Users invoke the brew command directly to install, upgrade, and remove these formulae.

Following are the versions available.

  • kcp_cli v0.11.0 for that release of kcp
  • kubestellar_cli v0.9.0, for that release of KubeStellar.


The kubeflex repo holds kubeflex, an independent component that we anticipate using as a provider for the Space framework in the future.