Allow to set custom PUID/PGID

Dockerfile

@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:experimental
-FROM --platform=${TARGETPLATFORM:-linux/amd64} adoptopenjdk:12-jre-hotspot
+FROM --platform=${TARGETPLATFORM:-linux/amd64} adoptopenjdk:12-jre-hotspot as suexec
 
 ARG BUILD_DATE
 ARG VCS_REF
@@ -9,6 +9,21 @@ ARG TARGETPLATFORM
 ARG BUILDPLATFORM
 RUN printf "I am running on ${BUILDPLATFORM:-linux/amd64}, building for ${TARGETPLATFORM:-linux/amd64}\n$(uname -a)\n"
 
+RUN  apt-get update \
+  && apt-get install -y --no-install-recommends \
+    gcc \
+    libc-dev \
+  && curl -o /usr/local/bin/su-exec.c https://raw.githubusercontent.com/ncopa/su-exec/master/su-exec.c \
+  && gcc -Wall /usr/local/bin/su-exec.c -o/usr/local/bin/su-exec \
+  && chown root:root /usr/local/bin/su-exec \
+  && chmod 0755 /usr/local/bin/su-exec
+
+FROM --platform=${TARGETPLATFORM:-linux/amd64} adoptopenjdk:12-jre-hotspot
+
+ARG BUILD_DATE
+ARG VCS_REF
+ARG VERSION
+
 LABEL maintainer="CrazyMax" \
   org.label-schema.build-date=$BUILD_DATE \
   org.label-schema.name="jetbrains-license-server" \
@@ -23,7 +38,9 @@ LABEL maintainer="CrazyMax" \
 ENV JLS_PATH="/opt/jetbrains-license-server" \
   JLS_VERSION="21137" \
   JLS_SHA256="05241f0d41644ecc7679a879c829e57d423e151b997b45c5e986d498d6fe2f21" \
-  TZ="UTC"
+  TZ="UTC" \
+  PUID="1000" \
+  PGID="1000"
 
 RUN apt-get update \
   && apt-get install -y \
@@ -38,17 +55,16 @@ RUN apt-get update \
   && rm -f "/tmp/jls.zip" \
   && chmod a+x "$JLS_PATH/bin/license-server.sh" \
   && ln -sf "$JLS_PATH/bin/license-server.sh" "/usr/local/bin/license-server" \
-  && groupadd -f -g 1000 jls \
-  && useradd -o -s /bin/bash -d /data -u 1000 -g 1000 -m jls \
+  && groupadd -f -g ${PGID} jls \
+  && useradd -o -s /bin/bash -d /data -u ${PUID} -g jls -m jls \
   && chown -R jls. /data "$JLS_PATH" \
   && apt-get clean \
   && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
+COPY --from=suexec /usr/local/bin/su-exec /usr/local/bin/su-exec
 COPY entrypoint.sh /entrypoint.sh
 RUN chmod a+x /entrypoint.sh
 
-USER jls
-
 EXPOSE 8000
 WORKDIR /data
 VOLUME [ "/data" ]