Just bootstrapped a single-node k3s on Container-O...
# k3sw
worried-park-81354
08/13/2025, 6:40 PMJust bootstrapped a single-node k3s on Container-Optimized OS (GCPs docker-only immutable OS). Anything I'm missing? It was too easy! I'm assuming https://get.k3s.io does not work on this? I looked through the script and most of it's assumptions are that you have a package manager.
For going into multi-node, i'll want an external datastore but other than that... I just need to use tls-san, a pre-chosen token, and...? do i need to run --cluster-init on the first k3s server up?
c
creamy-pencil-82913
08/13/2025, 6:41 PMthe only assumptions about package manager are for installing the selinux package. nothing else uses that.
creamy-pencil-82913
08/13/2025, 6:42 PMThe install script does assume that you are using systemd or openrc, and that things that are written to disk under /etc/rancher and /var/lib/rancher will stick around across reboots. We don’t test on COOS so I don’t know what other issues you may run into.
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worried-park-81354
08/13/2025, 6:50 PMgot it! That makes sense. I'm running k3s via docker itself and there was info for that on the site. /etc/rancher and /var/lib/rancher are in the docker containers and anything custom i need i've been creating via cloud-init and bind-mounting into it.
i have tested rebooting the machine but once i go multi node i will need an external datastore for when any nodes, agent or server, get replaced?
I haven't tried k3d but im considering it.
worried-park-81354
08/13/2025, 6:53 PMthis is the gist of it https://gist.github.com/sheenobu/3ebc74e82b78d274fe3d19c52cb9a266 .
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creamy-pencil-82913
08/13/2025, 6:54 PMI would not recommend running K3s in docker if you are trying to set up a true multi-node cluster
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worried-park-81354
08/13/2025, 6:55 PMyeah?
c
creamy-pencil-82913
08/13/2025, 6:55 PMno, we don’t test that or support it. If you want multiple k3s nodes on multiple hosts, run it on the host itself - not in docker.
creamy-pencil-82913
08/13/2025, 6:55 PMk3d is for running multi-node k3s cluster in docker on a single host. It does not support spanning hosts.
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worried-park-81354
08/13/2025, 6:56 PMoh got it.
worried-park-81354
08/13/2025, 7:05 PMfun fun. I just have to get the k3s binary and install script onto the host itself. I can then use --docker on COS i assume (not married to docker but a like having the mostly immutable OS)
Thank you for the guidance and input!