Notes on Installing Minecraft Server (Java Edition) on Kubernetes

Warning

This article was automatically translated by OpenAI (gpt-4o-mini).It may be edited eventually, but please be aware that it may contain incorrect information at this time.

Minecraft Server has a feature-rich helm chart, making it easy to operate when installed on Kubernetes.

In this article, I will document the installation of Minecraft Server on Kind (Kubernetes in Docker) as a testing environment.

Creating a Kind Cluster

brew install kind
kind create cluster

$ kubectl get node -owide
NAME                 STATUS   ROLES           AGE   VERSION   INTERNAL-IP     EXTERNAL-IP   OS-IMAGE                         KERNEL-VERSION                        CONTAINER-RUNTIME
kind-control-plane   Ready    control-plane   39s   v1.32.0   192.168.107.2   <none>        Debian GNU/Linux 12 (bookworm)   6.12.5-orbstack-00287-gf8da5d508983   containerd://1.7.24

Installing MetalLB

I am using OrbStack as the Docker Runtime. With OrbStack, routing from the Mac host to a Service of type=LoadBalancer is possible. We will install MetalLB to ensure that an External IP is assigned to a Service of type=LoadBalancer on Kind.

kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.9/config/manifests/metallb-native.yaml
kubectl wait --namespace metallb-system \
             --for=condition=ready pod \
             --selector=app=metallb \
             --timeout=90s

Next, we will obtain the IPv4 Subnet of the Docker Network.

SUBNET=$(docker network inspect -f '{{(index (index .IPAM.Config 1) "Subnet")}}' kind)

Let's check it.

$ echo $SUBNET
192.168.107.0/24

Tip

If you cannot obtain it, try SUBNET=$(docker network inspect -f '{{(index (index .IPAM.Config 0) "Subnet")}}' kind).

Now, we will set the range of IPs that MetalLB will assign. In this example, we will target 192.168.107.200-192.168.107.250.

cat <<EOF > metallb.yaml
---
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: example
  namespace: metallb-system
spec:
  addresses:
  - $(echo $SUBNET | cut -d. -f1-3).200-$(echo $SUBNET | cut -d. -f1-3).250
---
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: empty
  namespace: metallb-system
---
EOF
kubectl apply -f metallb.yaml

Installing Minecraft Server

With the preparations complete, we can finally install the Minecraft Server.

We will use the helm chart from https://github.com/itzg/minecraft-server-charts/tree/master/charts/minecraft.

The Server's IP will be fixed to the following IP.

MINECRAFT_IP=$(echo $SUBNET | cut -d. -f1-3).222

$ echo $MINECRAFT_IP 
192.168.107.222

Create the helm-values.yaml file. Here, we will install the Vanilla Server, but you can choose "VANILLA", "FORGE", "PAPER", etc. for the type. For available types, please refer to this link.

cat <<EOF > helm-values.yaml
---
minecraftServer:
  eula: "TRUE"
  type: "VANILLA"
  version: "1.21.4"
  difficulty: easy
  gameMode: creative
  overrideServerProperties: true
  serviceType: LoadBalancer
  loadBalancerIP: $MINECRAFT_IP
  externalTrafficPolicy: Local
  memory: 4096M
  rcon:
    enabled: true
resources:
  requests:
    memory: 3.5Gi
persistence:
  dataDir:
    enabled: true
    Size: 8Gi
---
EOF

Tip

I am operating on Oracle Cloud Infrastructure Container Engine for Kubernetes (OKE).
For the helm-values.yaml on OKE, please refer to this link.

Now, let's install the Minecraft Server using helm.

helm upgrade --install \
  -n minecraft minecraft itzg/minecraft \
  -f helm-values.yaml \
  --create-namespace \
  --wait

After a while, the Pod will be Ready, and the LoadBalancer will be created with the specified External IP.

$ kubectl get pod,svc -n minecraft 
NAME                                       READY   STATUS    RESTARTS   AGE
pod/minecraft-minecraft-58746c5689-lcwxw   1/1     Running   0          66s

NAME                               TYPE           CLUSTER-IP      EXTERNAL-IP       PORT(S)           AGE
service/minecraft-minecraft        LoadBalancer   10.96.5.89      192.168.107.222   25565:32239/TCP   66s
service/minecraft-minecraft-rcon   ClusterIP      10.96.218.111   <none>            25575/TCP         66s

You can also check the status with the helm command.

$ helm list -A
NAME     	NAMESPACE	REVISION	UPDATED                            	STATUS  	CHART           	APP VERSION
minecraft	minecraft	1       	2025-01-03 16:47:39.39652 +0900 JST	deployed	minecraft-4.23.3	SeeValues

Now, connect to this Server from the client.

Successfully connected.

You can uninstall it with the following command. If you are on kind, you can experiment freely.

helm uninstall -n minecraft minecraft --wait

IK.AM