Should I keep shared or separate k8s clusters? - eviltoast

I’ve been in the process of migrating a lot things back to kubernetes, and I’m debating whether I should have separate private and public clusters.

Some stuff I’ll keep out of kubernetes and leave in separate vms, like nextcloud/immich/etc. Basically anything I think would be more likely to have sensitive data in it.

I also have a few public-facing things like public websites, a matrix server, etc.

Right now I’m solving this by having two separate ingress controllers in one cluster - one for private stuff only available over a vpn, and one only available over public ips.

The main concern I’d have is reducing the blast radius if something gets compromised. But I also don’t know if I really want to maintain multiple personal clusters. I am using Omni+Talos for kubernetes, so it’s not too difficult to maintain two clusters. It would be more inefficient as far as resources go since some of the nodes are baremetal servers and others are only vms. I wouldn’t be able to share a large baremetal server anymore, unless I split it into vms.

What are y’all’s opinions on whether to keep everything in one cluster or not?

  • FrederikNJS@lemm.eeEnglish
    6·
    3 months ago

    I really don’t see much benefit to running two clusters.

    I’m also running single clusters with multiple ingress controllers both at home and at work.

    If you are concerned with blast radius, you should probably first look into setting up Network Policies to ensure that pods can’t talk to things they shouldn’t.

    There is of course still the risk of something escaping the container, but the risk is rather low in comparison. There are options out there for hardening the container runtime further.

    You might also look into adding things that can monitor the cluster for intrusions or prevent them. Stuff like running CrowdSec on your ingresses, and using Falco to watch for various malicious behaviour.

    • johntashOPEnglish
      1·
      3 months ago

      Network Policies are a good idea, thanks.

      I was more worried about escaping the container, but maybe I shouldn’t be. I’m using Talos now as the OS and there isn’t much on the OS as it is. I can probably also enforce all of my public services to run as non-root users and not allow privileged containers/etc.

      Thanks for recommending crowdsec/falco too. I’ll look into those