Adds the ability to change the uid and gid at runtime

Dockerfile

@@ -21,6 +21,8 @@ ENV RENDER_POI "true"
 ENV RENDER_SIGNS_FILTER "-- RENDER --"
 ENV RENDER_SIGNS_HIDE_FILTER "false"
 ENV RENDER_SIGNS_JOINER "<br />"
+ENV UID 1000
+ENV GID 1000
 
 # ---------------------------- #
 # INSTALL & CONFIGURE DEFAULTS #
@@ -72,6 +74,4 @@ COPY download_url.py /home/minecraft/download_url.py
 
 RUN chown minecraft:minecraft -R /home/minecraft/
 
-USER minecraft
-
 CMD ["bash", "/home/minecraft/entrypoint.sh"]

README.md

@@ -57,3 +57,9 @@ _Note:_ The `latest` Docker tag is rebuilt daily. If there are changes to the [u
 
 - `RENDER_SIGNS_JOINER`
   Default Value: `<br />`. Set to the string that should be used to join the lines on the sign while rendering. Value of `"<br />"` will make each in-game line it's own line on the render. A value of `" "` will make all the in-game lines a single line on the render.
+
+- `UID`
+  Default Value: 1000. Set to the UID of the user the container process should run as.
+
+- `GID`
+  Default Value: 1000. Set to the GID of the user the container process should run as.

entrypoint.sh

@@ -1,4 +1,16 @@
 #!/bin/bash
+if [ $(id -u) = 0 ]; then
+  echo "UID: ${UID}"
+  usermod -u ${UID} minecraft > /dev/null 2>&1
+  echo "GID: ${GID}"
+  groupmod -g ${GID} minecraft > /dev/null 2>&1
+  echo "Updating permissions..."
+  chown -R minecraft:minecraft /home/minecraft/render
+  echo "Done."
+  echo "Starting Overviewer."
+  su -c "bash $0" minecraft
+else
+
 set -o errexit
 
 # Require MINECRAFT_VERSION environment variable to be set (no default assumed)
@@ -43,3 +55,5 @@ if [ "$RENDER_POI" == "true" ]; then
   # shellcheck disable=SC2086
   overviewer.py --config "$CONFIG_LOCATION" --genpoi $ADDITIONAL_ARGS_POI
 fi
+
+fi