NOTE: Work In Progress
This is an virtual kubelet provider that interacts with systemd. The aim is to make this to work with K3S and go from there.
vks will start pods as plain processes, there are no cgroups (yet, maybe systemd will allow for
this easily), but generally there is no isolation. You basically use the k8s control plane to start
linux processes. There is also no address space allocated to the PODs specically, you are using the
host's networking.
"Images" are referencing (Debian) packages, these will be apt-get installed. Discoverying that an installed package is no longer used is hard, so this will not be done.
- Pods can contain multiple containers. In systemd each container is a Unit (file). How can we keep track of these diff. Units and re-create the Pod when we need to?
- Pod storage, secret etc. Just something on disk?
/var/lib/<something>? - How to provision a Debian system to be able to join a k3s cluster? Something very minimal is needed here. Maybe getting to k3s super early will help. We can then install extra things to configure?
- Add a private repo for debian packages. I.e. I want to install latest CoreDNS which isn't in Debian. I need to add a repo for this... How?
Download k3s from it's releases on GitHub, you just need the k3s binary. Use the k3s/k3s shell
script to start it - this assumes k3s sits in "~/tmp/k3s". The script basically starts k3s with
basically everything disabled.
Compile cmd/virtual-kubelet and start it with:
./cmd/virtual-kubelet/virtual-kubelet --kubeconfig ~/.rancher/k3s/server/cred/admin.kubeconfig \
--enable-node-lease --disable-taint
Now a k3s kubcetl get nodes should show the virtual kubelet as a node:
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
draak Ready agent 6s v1.18.4 <none> <none> Ubuntu 20.04.1 LT 5.4.0-53-generic systemd 245 (245.4-4ubuntu3.3)
draak is my machine's name.
THIS IS AS FAR AS I AM RIGHT NOW.
- Scheduling a pod doesn't seem to connect to my virtual kubelet