node-installer: k0s single node

[vdice]

I am new to k0s but was running through the motions of installing the shim on a local k0s cluster, thanks to the support added recently in #135

I followed the k0s quickstart here and went with the easy-mode, single node k0s that includes the controller and worker functions with the default configuration

In this mode, the systemctl service is k0scontroller rather than k0sworker. The latter is used in the node-installer logic here. Therefore, shim installation fails with the following:

$ k -n kwasm logs pod/lima-shimvm-provision-kwasm-nzwz6
Failed to restart k0sworker.service: Unit k0sworker.service not found.

Here's the systemctl service I see:

$ systemctl status k0sworker
Unit k0sworker.service could not be found.
$ systemctl status k0scontroller
● k0scontroller.service - k0s - Zero Friction Kubernetes
     Loaded: loaded (/etc/systemd/system/k0scontroller.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2024-06-28 10:56:04 MDT; 8min ago
     ...

Do we want to update the node-installer logic to support this single-node scenario? Or document that a multi-node setup (i.e. with an additional worker node/systemctl service) is required? cc @Ajpantuso

[Ajpantuso]

I think it's sensible to check if it's a worker or a controller with something like:

if systemctl list-units | grep -q k0sworker; then
...
else
...
fi