Usage

Starting simple server

Apply Minecraft Custom Resouce

$ cat <<EOF > minecraft-sample.yaml
apiVersion: mcing.kmdkuk.com/v1alpha1
kind: Minecraft
metadata:
  name: minecraft-sample
spec:
  podTemplate:
    spec:
      containers:
        - name: minecraft
          image: itzg/minecraft-server:java8
          env:
            - name: TYPE
              value: "SPIGOT"
            - name: EULA
              value: "true"
  serviceTemplate:
    spec:
      type: NodePort
  volumeClaimTemplates:
    - metadata:
        name: minecraft-data
      spec:
        accessModes: [ "ReadWriteOnce" ]
        storageClassName: standard
        resources:
          requests:
            storage: 1Gi
  serverPropertiesConfigMapName: mcing-server-props
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: mcing-server-props
data:
  motd: "[this is test]A Vanilla Minecraft Server powered by MCing"
  pvp: "true"
  difficulty: "hard"
EOF
$ kubectl apply -f minecraft-sample.yaml

# check resources 
$ kubectl get minecrafts.mcing.kmdkuk.com minecraft-sample
NAME               AGE
minecraft-sample   2m41s

$ kubectl get statefulsets.apps mcing-minecraft-sample
NAME               READY   AGE
mcing-minecraft-sample   1/1     2m47s

$ kubectl get persistentvolumeclaims minecraft-data-minecraft-sample-0
NAME                                STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
minecraft-data-mcing-minecraft-sample-0   Bound    pvc-220c9ba1-2395-48ed-a18a-c9d3d7788a6c   1Gi        RWO            standard       3h58m

$ kubectl get service
NAME                              TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                           AGE
kubernetes                        ClusterIP   10.96.0.1      <none>        443/TCP                           12m
mcing-minecraft-sample            NodePort    10.96.232.50   <none>        25565:30088/TCP,25575:30446/UDP   103s
mcing-minecraft-sample-headless   ClusterIP   None           <none>        25565/TCP,25575/UDP               103s

$ kubectl get configmaps
NAME                     DATA   AGE
kube-root-ca.crt         1      13m
mcing-minecraft-sample   1      2m47s
mcing-server-props       3      2m47s

When you apply Minecraft Custom Resource, several resources will be created.

Access the server

You can customize the Service (e.g. change type to LoadBalancer) using ServiceTemplate in the Minecraft Custom Resource to access the server. Alternatively, you can use port-forward to verify access quickly.
```
kubectl port-forward svc/minecraft-sample 25565:25565
```

If you edit the ConfigMap specified by .spec.serverPropertiesConfigMapName in the Minecraft resource, it will automatically replace server.properties and then execute the /reload command. Note: There are some cases where the configuration will not be updated even if you run the /reload command. (In the case of TYPE=SPIGOT, we have confirmed that the configuration is updated automatically.)

The following ConfigMap can be applied to other JSON configuration files.

apiVersion: v1
kind: ConfigMap
metadata:
  name: other-props
data:
  banned-ips.json: |
    []
  banned-players.json: |
    []
  whitelist.json: |
    []
  ops.json: |
    []

It can be applied by specifying a name, such as otherConfigMapName: other-props.

Warning

Currently, these files are overwritten by the ConfigMap content on every Pod startup. This means any in-game changes (e.g. /ban, /op) that are not reflected in the ConfigMap will be lost when the Pod restarts. This behavior is a known issue.

RCON Configuration

By default, the controller automatically generates a Secret named <instance-name>-rcon-password containing a random password for RCON. The password is stored in the key rcon-password. The controller injects this password into the Minecraft container as the environment variable RCON_PASSWORD.

If you want to use your own password, you can specify an existing Secret name in .spec.rconPasswordSecretName.

apiVersion: mcing.kmdkuk.com/v1alpha1
kind: Minecraft
metadata:
  name: minecraft-sample
spec:
  rconPasswordSecretName: my-rcon-secret
  # ... other fields

The Secret must contain the key rcon-password.

apiVersion: v1
kind: Secret
metadata:
  name: my-rcon-secret
stringData:
  rcon-password: "your-super-strong-password"

Auto-Pause

MCing supports automatic server pausing when no players are connected, using lazymc. This helps reduce resource usage for idle servers.

Enabling Auto-Pause

apiVersion: mcing.kmdkuk.com/v1alpha1
kind: Minecraft
metadata:
  name: minecraft-sample
spec:
  autoPause:
    enabled: true
    timeoutSeconds: 300  # Pause after 5 minutes of inactivity (default)
  # ... other fields

How it works

When enabled, lazymc runs as the main process and proxies connections to the Minecraft server
The Minecraft server starts when a player connects
After timeoutSeconds of no player activity, the server is paused
The server automatically resumes when a new player connects

Note

Auto-pause is enabled by default. Set autoPause.enabled: false to disable it.

Operators and Whitelist

MCing can manage operators and whitelist through the Minecraft CR spec.

Operators

spec:
  ops:
    users:
      - player1
      - player2

The controller executes /op or /deop commands via RCON to sync the operators list.

Whitelist

spec:
  whitelist:
    enabled: true
    users:
      - allowed_player1
      - allowed_player2

When whitelist.enabled is true, the controller executes /whitelist on and manages the whitelist via /whitelist add and /whitelist remove commands.

Backup and Download

MCing provides a kubectl plugin for downloading server data.

Installing kubectl-mcing

go install github.com/kmdkuk/mcing/cmd/kubectl-mcing@latest

Or download from GitHub Releases.

Downloading Server Data

kubectl mcing download <minecraft-name> [-o output.tar.gz] [-n namespace]

This command:

Executes save-off to disable auto-save
Executes save-all flush to ensure all data is written
Compresses and downloads the /data directory
Executes save-on to re-enable auto-save

Excluding Files from Backup

You can exclude files from the backup using the backup.excludes field:

spec:
  backup:
    excludes:
      - "*.jar"
      - "logs/*"
      - "cache/*"

mc-router (Hostname-based Routing)

When mc-router is enabled on the controller, you can use custom hostnames to access your Minecraft servers.

Using Custom Hostname

spec:
  externalHostname: "survival.mc.example.com"

If not specified, the hostname is automatically generated as <name>.<namespace>.<default-domain>.

DNS Configuration

Point a wildcard DNS record to the mc-router service’s external IP:

*.mc.example.com -> <mc-router-external-ip>

Players can then connect using hostnames like survival.mc.example.com:25565.

See Deploy MCing for controller configuration.

MCing Documentation