mc: restore UID and GID options

for #234

minecraft-server/Dockerfile

@@ -7,6 +7,7 @@ RUN apk add --no-cache -U \
           imagemagick \
           lsof \
           su-exec \
+          shadow \
           bash \
           curl iputils wget \
           git \
@@ -57,5 +58,3 @@ ENV JVM_XX_OPTS="-XX:+UseG1GC" MEMORY="1G" \
     LEVEL_TYPE=DEFAULT GENERATOR_SETTINGS= WORLD= MODPACK= SERVER_PORT=25565 ONLINE_MODE=TRUE CONSOLE=true
 
 COPY start* /
-
-USER minecraft

minecraft-server/README.md

@@ -733,6 +733,13 @@ Allows users to use flight on your server while in Survival mode, if they have a
 
 ## Miscellaneous Options
 
+### Running as alternate user/group ID
+
+By default, the container will switch to user ID 1000 and group ID 1000;
+however, you can override those values by setting `UID` and `GID`, respectively.
+The container will also skip user switching if the `--user`/`-u` argument
+is passed to `docker run`.
+
 ### Memory Limit
 
 By default, the image declares a Java initial and maximum memory limit of 1 GB. There are several

minecraft-server/start

@@ -1,98 +1,13 @@
 #!/bin/bash
 
-shopt -s nullglob
+if [ $(id -u) = 0 ]; then
-
+  if [[ -v UID ]]; then
-#umask 002
+    usermod -u $UID minecraft
-export HOME=/data
-
-if [ ! -e /data/eula.txt ]; then
-  if [ "$EULA" != "" ]; then
-    echo "# Generated via Docker on $(date)" > eula.txt
-    echo "eula=$EULA" >> eula.txt
-    if [ $? != 0 ]; then
-      echo "ERROR: unable to write eula to /data. Please make sure attached directory is writable by uid=${UID}"
-      exit 2
-    fi
-  else
-    echo ""
-    echo "Please accept the Minecraft EULA at"
-    echo "  https://account.mojang.com/documents/minecraft_eula"
-    echo "by adding the following immediately after 'docker run':"
-    echo "  -e EULA=TRUE"
-    echo ""
-    exit 1
   fi
+  if [[ -v GID ]]; then
+    groupmod -g $GID minecraft
+  fi
+  su-exec minecraft:minecraft /start-configuration
+else
+  exec /start-configuration
 fi
-
-echo "Running as '$(id -u):$(id -g)' with /data as '$(ls -lnd /data)'"
-
-if ! touch /data/.verify_access; then
-  echo "ERROR: /data doesn't seem to be writable. Please make sure attached directory is writable by uid=$(id -u)"
-  exit 2
-fi
-
-rm /data/.verify_access || true
-
-if [[ $PROXY ]]; then
-    export http_proxy="$PROXY"
-    export https_proxy="$PROXY"
-    echo "INFO: Giving proxy time to startup..."
-    sleep 5
-fi
-
-export SERVER_PROPERTIES=/data/server.properties
-export VERSIONS_JSON=https://launchermeta.mojang.com/mc/game/version_manifest.json
-
-echo "Checking version information."
-case "X$VERSION" in
-  X|XLATEST|Xlatest)
-    export VANILLA_VERSION=`curl -fsSL $VERSIONS_JSON | jq -r '.latest.release'`
-  ;;
-  XSNAPSHOT|Xsnapshot)
-    export VANILLA_VERSION=`curl -fsSL $VERSIONS_JSON | jq -r '.latest.snapshot'`
-  ;;
-  X[1-9]*)
-    export VANILLA_VERSION=$VERSION
-  ;;
-  *)
-    export VANILLA_VERSION=`curl -fsSL $VERSIONS_JSON | jq -r '.latest.release'`
-  ;;
-esac
-
-cd /data
-
-export ORIGINAL_TYPE=${TYPE}
-
-echo "Checking type information."
-case "$TYPE" in
-  *BUKKIT|*bukkit|SPIGOT|spigot)
-    exec /start-deployBukkitSpigot $@
-  ;;
-
-  PAPER|paper)
-    exec /start-deployPaper $@
-  ;;
-
-  FORGE|forge)
-    exec /start-deployForge $@
-  ;;
-
-  FTB|ftb)
-    exec /start-deployFTB $@
-  ;;
-
-  VANILLA|vanilla)
-    exec /start-deployVanilla $@
-  ;;
-
-  SPONGEVANILLA|spongevanilla)
-    exec /start-deploySpongeVanilla $@
-  ;;
-
-  *)
-      echo "Invalid type: '$TYPE'"
-      echo "Must be: VANILLA, FORGE, BUKKIT, SPIGOT, PAPER, FTB, SPONGEVANILLA"
-      exit 1
-  ;;
-
-esac

minecraft-server/start-configuration

@@ -0,0 +1,98 @@
+#!/bin/bash
+
+shopt -s nullglob
+
+#umask 002
+export HOME=/data
+
+if [ ! -e /data/eula.txt ]; then
+  if [ "$EULA" != "" ]; then
+    echo "# Generated via Docker on $(date)" > eula.txt
+    echo "eula=$EULA" >> eula.txt
+    if [ $? != 0 ]; then
+      echo "ERROR: unable to write eula to /data. Please make sure attached directory is writable by uid=${UID}"
+      exit 2
+    fi
+  else
+    echo ""
+    echo "Please accept the Minecraft EULA at"
+    echo "  https://account.mojang.com/documents/minecraft_eula"
+    echo "by adding the following immediately after 'docker run':"
+    echo "  -e EULA=TRUE"
+    echo ""
+    exit 1
+  fi
+fi
+
+echo "Running as '$(id -u):$(id -g)' with /data as '$(ls -lnd /data)'"
+
+if ! touch /data/.verify_access; then
+  echo "ERROR: /data doesn't seem to be writable. Please make sure attached directory is writable by uid=$(id -u)"
+  exit 2
+fi
+
+rm /data/.verify_access || true
+
+if [[ $PROXY ]]; then
+    export http_proxy="$PROXY"
+    export https_proxy="$PROXY"
+    echo "INFO: Giving proxy time to startup..."
+    sleep 5
+fi
+
+export SERVER_PROPERTIES=/data/server.properties
+export VERSIONS_JSON=https://launchermeta.mojang.com/mc/game/version_manifest.json
+
+echo "Checking version information."
+case "X$VERSION" in
+  X|XLATEST|Xlatest)
+    export VANILLA_VERSION=`curl -fsSL $VERSIONS_JSON | jq -r '.latest.release'`
+  ;;
+  XSNAPSHOT|Xsnapshot)
+    export VANILLA_VERSION=`curl -fsSL $VERSIONS_JSON | jq -r '.latest.snapshot'`
+  ;;
+  X[1-9]*)
+    export VANILLA_VERSION=$VERSION
+  ;;
+  *)
+    export VANILLA_VERSION=`curl -fsSL $VERSIONS_JSON | jq -r '.latest.release'`
+  ;;
+esac
+
+cd /data
+
+export ORIGINAL_TYPE=${TYPE}
+
+echo "Checking type information."
+case "$TYPE" in
+  *BUKKIT|*bukkit|SPIGOT|spigot)
+    exec /start-deployBukkitSpigot $@
+  ;;
+
+  PAPER|paper)
+    exec /start-deployPaper $@
+  ;;
+
+  FORGE|forge)
+    exec /start-deployForge $@
+  ;;
+
+  FTB|ftb)
+    exec /start-deployFTB $@
+  ;;
+
+  VANILLA|vanilla)
+    exec /start-deployVanilla $@
+  ;;
+
+  SPONGEVANILLA|spongevanilla)
+    exec /start-deploySpongeVanilla $@
+  ;;
+
+  *)
+      echo "Invalid type: '$TYPE'"
+      echo "Must be: VANILLA, FORGE, BUKKIT, SPIGOT, PAPER, FTB, SPONGEVANILLA"
+      exit 1
+  ;;
+
+esac