MCing documentation

This is the documentation site for MCing. MCing is a Kubernetes operator for Minecraft server.

Getting started

1. Install cert-manager and apply MCing manifests

Deploying MCing

1. (Optional) Prepare cert-manager

   MCing depends on cert-manager to issue TLS certificate for admission webhooks. If cert-manager is not installed on your cluster, install it as follows:

   $ curl -fsLO https://github.com/jetstack/cert-manager/releases/latest/download/cert-manager.yaml
   $ kubectl apply -f cert-manager.yaml
   

2. Apply MCing manifests

   $ curl -fsLO https://github.com/kmdkuk/MCing/releases/latest/download/install.yaml
   $ kubectl apply -f install.yaml
   

Usage

Starting simple server

1. 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.

2. Access the server

   MCing does not yet have the ability to customize the Service, so you can use port-forward and other methods to check access to the server.

   $ kubectl port-forward svc/minecraft-sample 25565:25565
   

Configuration by ConfigMap

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. However, these files are updated from the command in actual operation. Therefore, they will be applied if the target files are not present at startup. (TODO: I'm trying to figure out how to successfully merge the JSON specified in ConfigMap with the JSON that actually exists).

Custom resources

Custom Resources

• Minecraft

Sub Resources

• MinecraftList
• MinecraftSpec
• ObjectMeta
• Ops
• PersistentVolumeClaim
• PodTemplateSpec
• ServiceTemplate
• Whitelist

Minecraft

Minecraft is the Schema for the minecrafts API

Back to Custom Resources

MinecraftList

MinecraftList contains a list of Minecraft

Back to Custom Resources

MinecraftSpec

MinecraftSpec defines the desired state of Minecraft

Back to Custom Resources

ObjectMeta

ObjectMeta is metadata of objects. This is partially copied from metav1.ObjectMeta.

Back to Custom Resources

Ops

Back to Custom Resources

PersistentVolumeClaim

PersistentVolumeClaim is a user's request for and claim to a persistent volume. This is slightly modified from corev1.PersistentVolumeClaim.

Back to Custom Resources

PodTemplateSpec

PodTemplateSpec describes the data a pod should have when created from a template. This is slightly modified from corev1.PodTemplateSpec.

Back to Custom Resources

ServiceTemplate

ServiceTemplate define the desired spec and annotations of Service

Back to Custom Resources

Whitelist

Back to Custom Resources