Portal:Toolforge/Admin/Kubernetes/lima-kilo
This page contains information on Toolforge lima-kilo, a project to help setting up a fake Toolforge local kubernetes environment in a given local machine (like a laptop), to help develop some of the Toolforge internal components.
The lima-kilo project is based on ansible.
Repository: https://gitlab.wikimedia.org/repos/cloud/toolforge/lima-kilo
Rationale
Developing some Toolforge kubernetes components can be challenging because Toolforge is not just a bare k8s deployment. It is Toolforge's kubernetes. There are custom admission webhooks, custom namespaces, a particular security model, some host files are expected to be present, etc.
The lima-kilo fakes most of this service context in a local environment in a way that, thanks to ansible, is lightweight, robust, deterministic, idempotent and easy to use.
The industry uses mostly 2 solutions for local kubernetes deployments like this:
Some of these product work best for different laptop operating systems (Debian, Ubuntu, mac OSX, etc). And the already-in-place modularity of lima-kilo allows to support the combo of these options, for example:
debian-kinddebian-minikubeosx-kindosx-minikube
Please note that not all of them might be supported/coded yet, and if you are the first to bring a new environment combo you might have to add support for it yourself. This should be rather easy though. Ask for help,
The project was mildly inspired by MediaWiki-Vagrant, and might in fact introduce vagrant support in the future.
Basic usage workflow
Usage should be rather simple:
- Git clone the repository
- make sure there is a playbook for your desired environment combo, check the
playbooks/directory. If not, ask for help with implementing a new one. - run the playbook, like
ansible-playbook -KD playbooks/kind-install.yaml - enjoy!
You may want to set up some local configuration to modify the lima-kilo behavior. This can be done in the ~/.toolforge-lima-kilo/userconfig.yaml file, see the README file for some hints.
Code conventions
Some informal code conventions:
- Everything
lima-kilodoes, it should be capable of undoing. - Therefore, there should be
installanduninstallplaybooks for each environment. - Playbooks should be idempotent (ie, if running them twice, the second time is basically a NOOP). This is a core principle of
ansible, but worth mentioning. - If an action is too invasive in the local system, a config option should be introduced to prevent/relax the action. Like installing / uninstalling packages that might be managed by hand by the user.
- When introducing changes, be mindful of previous
lima-kilodeployments others developers may have in their system. This is important for example when renaming resources. - Try to write playbooks as much OS-agnostic as possible. So the same playbook can be used in both OSX and Debian.