I'm new to Kubernetes and containerization and I'm trying to set up a game server, specifically for Valheim, within a Kubernetes environment I'm managing. I've set up Kubernetes on Hyper-V with one control plane and two worker nodes, but I'm struggling with the networking aspects, particularly with services and LoadBalancer configurations. I've installed kubectl, kubelet, and Helm, and I'm able to run commands to see the status of my pods and nodes. However, I don't fully grasp how to establish the correct networking for my game server, which operates on UDP ports 2456 and 2457.
I've read that MetalLB can help with this by providing an external IP for the LoadBalancer service, and I've created a configuration for it to assign IPs like 192.168.0.5. The problem lies in getting this setup to work correctly and understanding how traffic should flow to the server. I'm hoping someone can help me understand where to go from here or what steps I might be missing to connect successfully. Any guidance would be greatly appreciated!
5 Answers
Just a heads up, remember that MetalLB's IP range shouldn't overlap with your cluster's CIDR. It sounds like you're on the right track with using IPs from your home network, but just check to be sure there's no overlap!
It sounds like you just need to make sure your LoadBalancer service is correctly set up to select the pod running your game server. Following MetalLB's documentation on labeling should help ensure that everything routes as expected.
Thanks for the encouragement! It feels like I'm making progress, even if it's slow. I did update my post with some service details if you want to take a look.
Is everything on the same LAN? If your nodes are on different networks, you'll need to adjust your routing. But if they're all in the same LAN, it should be straightforward!
Yes, they are on the same LAN, which makes it even more confusing for me. I checked the pod logs and it shows valheim-server is waiting for the UDP query port to open, which might indicate a binding issue.
You need something to implement the LoadBalancer, similar to how you need to configure storage or runtime in Kubernetes. What CNI are you using? Some like Cilium provide Layer 2 load balancing that can be easily configured alongside MetalLB.
You're pretty close! Keep in mind that Kubernetes doesn't provide a built-in LoadBalancer; you need something like MetalLB to handle that. MetalLB will fake a LoadBalancer by announcing an external IP from one node per service. Just make sure your LoadBalancer service is set up to route traffic correctly to the pods that are running your game server. Once that's sorted, you'll be able to send traffic to that external IP! Just remember that the selected pod can change with each connection.
Also, if you're trying to grasp the underlying mechanics, I recommend checking out this visual guide I found. It really helps clarify how services work in Kubernetes: https://medium.com/swlh/kubernetes-services-simply-visually-explained-2d84e58d70e5
I'm not sure if it overlaps, but I read that as long as I use IPs that aren't assigned by DHCP, I should be okay.