Fixed UID/GID startup logic to properly handle running as root

Fixes #425

Dockerfile

@@ -29,8 +29,6 @@ RUN addgroup -g 1000 minecraft \
 
 EXPOSE 25565 25575
 
-RUN echo 'hosts: files dns' > /etc/nsswitch.conf
-
 ARG ARCH=amd64
 
 ARG EASY_ADD_VER=0.3.0

README.md

@@ -2,7 +2,7 @@
 [![Docker Pulls](https://img.shields.io/docker/pulls/itzg/minecraft-server.svg)](https://hub.docker.com/r/itzg/minecraft-server/)
 [![Docker Stars](https://img.shields.io/docker/stars/itzg/minecraft-server.svg?maxAge=2592000)](https://hub.docker.com/r/itzg/minecraft-server/)
 [![GitHub Issues](https://img.shields.io/github/issues-raw/itzg/docker-minecraft-server.svg)](https://github.com/itzg/docker-minecraft-server/issues)
-[![](https://img.shields.io/gitter/room/itzg/dockerfiles.svg?style=flat)](https://gitter.im/itzg/dockerfiles)
+[![Discord](https://img.shields.io/discord/660567679458869252)](https://discord.gg/DXfKpjB)
 [![](https://img.shields.io/badge/Donate-Buy%20me%20a%20coffee-orange.svg)](https://www.buymeacoffee.com/itzg)
 
 This docker image provides a Minecraft Server that will automatically download the latest stable
@@ -106,9 +106,9 @@ and start the server again with `docker start CONTAINERID` to pick up the new co
 
 To use a different Minecraft version, pass the `VERSION` environment variable, which can have the value
 
-* LATEST
+* LATEST (the default)
 * SNAPSHOT
-* (or a specific version, such as "1.7.9")
+* or a specific version, such as "1.7.9"
 
 For example, to use the latest snapshot:
 
@@ -118,6 +118,11 @@ or a specific version:
 
     docker run -d -e VERSION=1.7.9 ...
 
+When using "LATEST" or "SNAPSHOT" an upgrade can be performed by simply restarting the container. 
+During the next startup, if a newer version is available from the respective release channel, then
+the new server jar file is downloaded and used. _NOTE: over time you might see older versions of
+the server jar remain in the `/data` directory. It is safe to remove those._
+
 ## Healthcheck
 
 This image contains [Dinnerbone's mcstatus](https://github.com/Dinnerbone/mcstatus) and uses

k8s-examples/using-statefulset.yml

@@ -0,0 +1,50 @@
+---
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  labels:
+    app: example
+  name: example
+spec:
+  replicas: 1
+  serviceName: example
+  selector:
+    matchLabels:
+      app: example
+  template:
+    metadata:
+      labels:
+        app: example
+    spec:
+      containers:
+        - name: mc
+          image: itzg/minecraft-server
+          env:
+            - name: EULA
+              value: "TRUE"
+          volumeMounts:
+            - mountPath: /data
+              name: data
+  volumeClaimTemplates:
+    - metadata:
+        name: data
+      spec:
+        accessModes:
+          - ReadWriteOnce
+        resources:
+          requests:
+            storage: 1Gi
+---
+apiVersion: v1
+kind: Service
+metadata:
+  labels:
+    service: example
+  name: example
+spec:
+  ports:
+    - port: 25565
+      targetPort: 25565
+  selector:
+    app: example
+  type: LoadBalancer

start

@@ -4,19 +4,41 @@ umask 0002
 chmod g+w /data
 
 if [ $(id -u) = 0 ]; then
-  if [[ -v UID && $UID != $(id -u) ]]; then
-    usermod -u $UID minecraft
+  runAsUser=minecraft
+  runAsGroup=minecraft
+
+  if [[ -v UID ]]; then
+    if [[ $UID != 0 ]]; then
+      if [[ $UID != $(id -u minecraft) ]]; then
+        echo "Changing uid of minecraft to $UID"
+        usermod -u $UID minecraft
+      fi
+    else
+      runAsUser=root
+    fi
   fi
+
   if [[ -v GID ]]; then
-    groupmod -o -g $GID minecraft
+    if [[ $GID != 0 ]]; then
+      if [[ $GID != $(id -g minecraft) ]]; then
+        echo "Changing gid of minecraft to $GID"
+        groupmod -o -g $GID minecraft
+      fi
+    else
+      runAsGroup=root
+    fi
   fi
 
   if [[ $(stat -c "%u" /data) != $UID ]]; then
     echo "Changing ownership of /data to $UID ..."
-    chown -R minecraft:minecraft /data
+    chown -R ${runAsUser}:${runAsGroup} /data
   fi
 
-  exec su-exec minecraft:minecraft /start-configuration $@
+  if [[ ${SKIP_NSSWITCH_CONF^^} != TRUE ]]; then
+    echo 'hosts: files dns' > /etc/nsswitch.conf
+  fi
+
+  exec su-exec ${runAsUser}:${runAsGroup} /start-configuration $@
 else
   exec /start-configuration $@
 fi