Introduction

mc-operator is a production-grade Kubernetes Operator for managing Minecraft server deployments. It is built with .NET 10 and KubeOps 10, and is maintained under the dhv.sh umbrella.

What problem does it solve?

Running a Minecraft server on Kubernetes without an operator means manually writing and maintaining StatefulSets, Services, PersistentVolumeClaims, ConfigMaps, and webhook configs — then keeping them all consistent across environments. This is error-prone and tedious.

mc-operator turns server administration into a single Kubernetes resource:

apiVersion: mc-operator.dhv.sh/v1alpha1
kind: MinecraftServer
metadata:
  name: paper-survival
  namespace: minecraft
spec:
  acceptEula: true
  server:
    type: Paper
    version: "1.20.4"
  jvm:
    initialMemory: "2G"
    maxMemory: "4G"
  storage:
    size: "20Gi"

The operator takes care of the rest: provisioning storage, configuring the server, exposing it on the network, and continuously reconciling the desired state.

Supported server distributions

Type	Description
Vanilla	Official Mojang server jar
Paper	High-performance Paper fork — recommended for production
Spigot	Spigot with Bukkit API support
Bukkit	CraftBukkit server

All distributions are backed by the community-standard itzg/minecraft-server Docker image, which handles version management and configuration via environment variables.

Key capabilities

• CRD-driven: MinecraftServer is a first-class Kubernetes resource with a typed spec and status.
• Cluster management: MinecraftServerCluster manages multiple backend servers behind a Velocity proxy with automatic server registration and forwarding secret management.
• Admission webhooks: A validating webhook rejects invalid configurations before they reach the cluster. A mutating webhook applies sensible defaults.
• Safe data handling: PVCs are retained by default when a server is deleted, preventing accidental data loss.
• Zero-downtime version upgrades: When spec.prePull: true is set and a server version is changed, the operator pre-pulls the new container image and pre-downloads the Minecraft server jar to the data volume while the server is still running. The rolling update then only waits for the server process to start — not for any downloads.
• Pause/resume: Set spec.replicas: 0 to pause a server and retain all world data. Set back to 1 to resume.
• Status reporting: The operator continuously reports the server’s phase (Pending, Provisioning, Running, Paused, Failed), connection endpoint, and PVC status.
• Leader election: Deploy multiple operator replicas safely using built-in leader election.
• Helm chart: Clean, versioned Helm chart published to GHCR as an OCI artifact.

What it is not

mc-operator is a lifecycle manager — it manages server infrastructure, not game content. It does not:

• Install or manage plugins
• Handle automated world backups
• Provide RCON command routing

These are intentional scope decisions. See the Roadmap for future plans.