Switch from su to gosu

Using su causes issues with tini, because su creates a new process hierarchy tini cannot properly forward signals to its childs, causing the game server to not shutdown properly in some cases, using gosu fully fixes those issues

Dockerfile

@@ -11,6 +11,7 @@ ENV STEAMAPP core-keeper
 ENV STEAMAPPDIR "${HOMEDIR}/${STEAMAPP}-dedicated"
 ENV STEAMAPPDATADIR "${HOMEDIR}/${STEAMAPP}-data"
 ENV SCRIPTSDIR "${HOMEDIR}/scripts"
+ENV MODSDIR "${STEAMAPPDATADIR}/StreamingAssets/Mods"
 ENV DLURL https://raw.githubusercontent.com/escapingnetwork/core-keeper-dedicated
 
 RUN dpkg --add-architecture i386
@@ -23,6 +24,7 @@ RUN set -x \
 		libxi6 \
 		tini \
 		tzdata \
+		gosu \
 	&& rm -rf /var/lib/apt/lists/*
 
 # Setup X11 Sockets folder

scripts/entry.sh

@@ -32,7 +32,7 @@ fi
 if [ -f "/tmp/.X99-lock" ]; then rm /tmp/.X99-lock; fi
 
 if [[ "$(id -u)" -eq 0 ]]; then
-	exec su "${USER}" -c "exec bash ${SCRIPTSDIR}/setup.sh"
+	exec gosu "${USER}" bash "${SCRIPTSDIR}/setup.sh"
 else
 	exec bash "${SCRIPTSDIR}/setup.sh"
 fi