cloud-cluster/minecraft/mc-router.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: mc-router
  namespace: minecraft
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: services-watcher
  namespace: minecraft
rules:
  - apiGroups: [""]
    resources: ["services"]
    verbs: ["watch", "list"]
  - apiGroups: ["apps"]
    resources: ["statefulsets", "statefulsets/scale"]
    verbs: ["watch", "list", "get", "update"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: mc-router-services-watcher
  namespace: minecraft
subjects:
  - kind: ServiceAccount
    name: mc-router
    namespace: minecraft
roleRef:
  kind: ClusterRole
  name: services-watcher
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: v1
kind: Service
metadata:
  name: mc-router
  namespace: minecraft
spec:
  type: NodePort
  selector:
    run: mc-router
  ports:
    - targetPort: web
      name: web
      port: 8080
      nodePort: 30001
    - targetPort: proxy
      name: proxy
      port: 25565
      nodePort: 25565
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mc-router
  namespace: minecraft
  labels:
    run: mc-router
spec:
  selector:
    matchLabels:
      run: mc-router
  strategy:
    type: Recreate
  template:
    metadata:
      namespace: minecraft
      labels:
        run: mc-router
    spec:
      serviceAccountName: mc-router
      containers:
        - image: itzg/mc-router
          imagePullPolicy: Always
          name: mc-router
          args:
            [
              "--api-binding",
              ":8080",
              "--in-kube-cluster",
              "--auto-scale-up",
              "--debug",
            ]
          env:
            - name: AUTO_SCALE_UP
              value: "true"
          ports:
            - name: proxy
              containerPort: 25565
            - name: web
              containerPort: 8080
          resources:
            requests:
              memory: 50Mi
              cpu: "100m"
            limits:
              memory: 100Mi
              cpu: "250m"

# Cron job for stopping empty servers
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: mc-shutdown
  namespace: minecraft
rules:
  - apiGroups: ["apps"]
    resources: ["statefulsets", "statefulsets/scale"]
    verbs: ["list", "get", "update", "patch"]
  - apiGroups: [""]
    resources: ["pods", "pods/log"]
    verbs: ["get", "list"]
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: mc-shutdown
  namespace: minecraft
subjects:
  - kind: ServiceAccount
    name: mc-shutdown
    namespace: default
roleRef:
  kind: ClusterRole
  name: mc-shutdown
  apiGroup: "rbac.authorization.k8s.io"
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: mc-shutdown
  namespace: minecraft
---
apiVersion: batch/v1
kind: CronJob
metadata:
  name: mc-shutdown
  namespace: minecraft
spec:
  schedule: "*/5 * * * *"
  concurrencyPolicy: Forbid
  jobTemplate:
    spec:
      template:
        spec:
          serviceAccountName: mc-shutdown
          restartPolicy: OnFailure
          containers:
            - name: shutdown
              image: bitnami/kubectl:latest
              imagePullPolicy: IfNotPresent
              command:
                - /bin/bash
                - -c
                - source shutdown-script.sh
              volumeMounts:
                - name: shutdown-script
                  mountPath: /shutdown-script.sh
                  subPath: shutdown-script.sh
                  readOnly: true
          volumes:
            - name: shutdown-script
              configMap:
                name: shutdown-script
                items:
                  - key: shutdown-script.sh
                    path: shutdown-script.sh
# uses container label containertype=minecraft-server to find running servers
# TODO: get ownerReferences link to StatefulSet/name from pod metadate instead of sed string manipulation
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: shutdown-script
  namespace: minecraft
data:
  shutdown-script.sh: |
    #!/bin/bash
    MC_PODS=$(kubectl get pods -l containertype=minecraft-server -o=jsonpath="{range .items[*]}{.metadata.name},"| sed 's/,/\n/g')
    for p in $MC_PODS; do
      echo "found minecraft pod $p, sleeping 120 seconds to prevent shutdown before login"
      sleep 120
      deployment=$(echo $p |sed 's/-0//g')
      # check online player count in the mc server
      if [[ $(kubectl exec -i $p -- /usr/local/bin/mc-monitor status) == *"online=0"* ]] ;then
        kubectl scale statefulset $deployment --replicas=0
      fi
    done