How to manage Addons

See also: available Addons

To be as lightweight as possible, MicroK8s only installs the basics of a usable
Kubernetes install:

  • api-server
  • controller-manager
  • scheduler
  • kubelet
  • cni
  • kube-proxy

While this does deliver a pure Kubernetes experience with the smallest resource footprint possible, there are situations where you may require additional services. MicroK8s caters for this with the concept of “Addons” - extra services which can easily be added to MicroK8s. These addons can be enabled and disabled at any time, and most are pre-configured to ‘just work’ without any further set up.

For example, to enable the CoreDNS addon:

microk8s enable dns

These add-ons can be disabled at anytime using the disable command:

microk8s disable dns

… and you can check the list of available and installed addons at any time by running:

microk8s status

Note: Before installing add-ons which install extra client tools (e.g. Helm), be sure that the current user is part of the microk8s group, to avoid potential permission problems.

Addon Repositories

Starting from the v1.24 release, addons are organized in repositories. Repositories are essentially git projects in which users can place the addons they are interested in. To assist in creating a such repositories, the MicroK8s team maintains a template repository on github that can be forked to start a new addons collection. Although the template repository includes a HACKING.md guide with instructions on building a Python based demo addon, addons can be implemented in any programming language, even bash.

Addon repositories are found under /var/snap/microk8s/common/addons and can be edited in place. To ease the process of adding, removing and updating such repositories the microk8s addons repo command can be used. A repository under https://github.com/my-org/awesome-repo can be added on a MicroK8s cluster with:

microk8s addons repo add myrepo https://github.com/my-org/awesome-repo

An optional --reference flag can be used to point to a specific branch or tag inside the git repository.

The myrepo in the above example is the repository identifier. This identifier is used to differentiate addons with the same name found on separate addon repositories.

Removing and updating a repository is achieved with the microk8s addons repo remove and microk8s addons repo update commands respectively.

By default the MicroK8s ships with two repositories:

  • core, with essential addons maintained by the MicroK8s team, and

  • community, with community maintained addons.

Note: On fresh installs only the core repository is enabled by default. The community repository can be easily added at any time with: microk8s enable community.