Refactor Dockerfile and custom_startup.sh for improved Forge installation and startup process

Dockerfile

@@ -1,14 +1,15 @@
 ARG BASE_TAG="develop"
 ARG BASE_IMAGE="core-ubuntu-jammy"
-FROM kasmweb/${BASE_IMAGE}:${BASE_TAG}
-
+FROM kasmweb/$BASE_IMAGE:$BASE_TAG
 USER root
 
 ENV HOME /home/kasm-default-profile
 ENV STARTUPDIR /dockerstartup
-
+ENV INST_SCRIPTS $STARTUPDIR/install
 WORKDIR $HOME
 
+######### Customize Container Here ###########
+
 ### Install Java 17
 RUN apt-get update && \
     apt-get install -y openjdk-17-jdk && \
@@ -28,11 +29,20 @@ RUN apt-get update && apt-get install -y jq curl && \
     apt-get autoremove -y
 
 ### Add the startup script
-COPY custom_startup.sh $STARTUPDIR/custom_startup.sh
+COPY ./custom_startup.sh $STARTUPDIR/custom_startup.sh
 RUN chmod +x $STARTUPDIR/custom_startup.sh
+RUN chmod 755 $STARTUPDIR/custom_startup.sh
 
 ### Optional: Single app UI tweaks
 RUN cp $HOME/.config/xfce4/xfconf/single-application-xfce-perchannel-xml/* \
     $HOME/.config/xfce4/xfconf/xfce-perchannel-xml/
 
-USER 1000
+######### End Customizations ###########
+
+RUN chown 1000:0 $HOME
+
+ENV HOME /home/kasm-user
+WORKDIR $HOME
+RUN mkdir -p $HOME && chown -R 1000:0 $HOME
+
+USER 1000

custom_startup.sh

@@ -1,5 +1,13 @@
 #!/bin/bash
+set -e
+
 export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
 export PATH=$JAVA_HOME/bin:$PATH
 
-/opt/forge/start.sh
+# Optional: maximize Forge window
+if [[ -x $STARTUPDIR/maximize_window.sh ]]; then
+  bash $STARTUPDIR/maximize_window.sh &
+fi
+
+# Run Forge and wait for it to close
+exec /opt/forge/start.sh