Selfhosted

I've gotten to the point where I have more than a few servers in my homelab and am looking for a way to increase reliability in case of an update. Two problems: 2 of the servers will be on Wifi and one is a Synology NAS. I can't do any wiring but I can put together a WiFi 6E network for the servers only, That means buying 4 Wifi 6E devices in a mix of types. As for Synology, it's container manager is a little odd so I expect to run a Linux VM and use that as my cluster node. That may mean buying more RAM as I haven't upgraded it. Hardware ranges from a 6 core CPU on the NAS (with a few important docker containers), 8 core on my main SFF server (which also runs my OpnSense VM inside Proxmox), 16 core Ryzen on my old big server, and a 10 year old NUC for fun. So the question is what do I use to orchestrate all the services I have. My Vaulwarden runs reliability but only on one system. I want better reliability for Pihole that automatically syncs settings. The NAS' docker implementation doesn't support gravity sync. Since everything I do runs in docker besides storage it seems Proxmox clusters is not the best option. That puts me between K8s and Docker Swarm. I'd like something that is simple to administer but resilien when hardware fails.