Configurable UID and GID

paper/Dockerfile

@@ -1,11 +1,15 @@
 FROM alpine:latest
 
+ENV UID=1000
+ENV GID=1000
+
 ARG JAVA=openjdk17
-RUN apk add --upgrade $JAVA curl jq
+RUN apk add --upgrade sudo shadow $JAVA curl jq
 
 ADD ./bin /usr/local/bin
 
-RUN adduser -D minecraft
+RUN groupadd -g $GID minecraft
+RUN useradd -u $UID -g $GID minecraft
 
 RUN mkdir /minecraft && chown -R minecraft /minecraft
 
@@ -13,11 +17,10 @@ VOLUME ["/minecraft"]
 
 WORKDIR /minecraft
 
-USER minecraft
-
 EXPOSE 25565
 
 ARG MC_VERSION
 ENV MC_VERSION=${MC_VERSION:-1.19.4}
 
-CMD sh -c "download_mc $MC_VERSION && java -Xmx2G -Xms2G -jar paper.jar"
+ENTRYPOINT ["setup"]
+CMD ["java", "-Xmx2G", "-Xms2G", "-jar", "paper.jar"]

paper/bin/configure_and_start

@@ -1,13 +1,8 @@
 #!/bin/sh
 
-if test "$EULA" != "true"; then
-	echo "You need to accept the Mojang EULA (using -e EULA=true) to run the server"
-	exit 1
-fi
-
 meta_dir="docker_meta"
 
-if test ! -f "$meta_dir/setup_done"; then
+if test ! -f "$meta_dir/config_done"; then
 	# TODO: Use config/paper-global.yml with new config keys for 1.19+ Paper
 	config_path="paper.yml"
 
@@ -35,10 +30,11 @@ EOF
 
 	mkdir -p "$meta_dir" && touch "$meta_dir/setup_done"
 else
-	echo "Setup is done"
+	echo "Configuration is done"
 fi
 
-version=$1
+echo $MC_VERSION
+version=$MC_VERSION
 echo "Downloading version $version"
 
 apiURL=https://api.papermc.io/v2/projects/paper
@@ -53,3 +49,6 @@ echo "Downloading to $PWD"
 wget -O paper.jar $url
 
 echo "eula=true" > eula.txt
+
+echo "> $@"
+exec "$@"

paper/bin/setup

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+if test "$EULA" != "true"; then
+	echo "You need to accept the Mojang EULA (using -e EULA=true) to run the server"
+	exit 1
+fi
+
+usermod -u $UID minecraft
+groupmod -g $GID minecraft
+chown -R minecraft:minecraft /minecraft
+
+exec sudo -E -u minecraft configure_and_start "$@"

velocity/Dockerfile

@@ -1,10 +1,14 @@
 FROM alpine:latest
 
-RUN apk add --upgrade openjdk17 curl jq
+ENV UID=1000
+ENV GID=1000
+
+RUN apk add --upgrade sudo shadow openjdk17 curl jq
 
 ADD ./bin /usr/local/bin
 
-RUN adduser -D velocity
+RUN groupadd -g $GID velocity
+RUN useradd -u $UID -g $GID velocity
 
 RUN mkdir /velocity && chown -R velocity /velocity
 
@@ -12,8 +16,7 @@ VOLUME ["/velocity"]
 
 WORKDIR /velocity
 
-USER velocity
-
 EXPOSE 25577
 
-CMD sh -c "download_velocity && java -Xmx500M -Xms500M -jar velocity.jar"
+ENTRYPOINT ["setup"]
+CMD ["java", "-Xmx500M", "-Xms500M", "-jar", "velocity.jar"]

velocity/bin/configure_and_start

@@ -28,3 +28,6 @@ echo "Full URL is: $url"
 
 echo "Downloading to $PWD"
 wget -O velocity.jar $url
+
+echo "> $@"
+exec "$@"

velocity/bin/setup

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+usermod -u $UID velocity
+groupmod -g $GID velocity
+chown -R velocity:velocity /velocity
+
+exec sudo -E -u velocity configure_and_start "$@"