Add launcher script that copies in default config

Dockerfile.bullseye-slim

@@ -25,4 +25,6 @@ RUN apt-get update && apt-get upgrade -y
 RUN apt-get install -y \
     zlib1g-dev
 COPY --from=builder /usr/local/pvpgn /usr/local/pvpgn
-ENTRYPOINT ["/usr/local/pvpgn/sbin/bnetd", "-D"]
+COPY --from=builder /usr/local/pvpgn/etc /usr/local/pvpgn-backup/etc
+COPY launch.sh /
+ENTRYPOINT ["/launch.sh"]

launch.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+set -e
+
+# If config directory is mounted to an empty volume,
+# copy in the default configuration
+if [ ! "$(ls -A /usr/local/pvpgn/etc)" ]; then
+    echo "Copying in default configuration"
+    cp -r /usr/local/pvpgn-backup/etc/* /usr/local/pvpgn/etc
+fi
+
+/usr/local/pvpgn/sbin/bnetd -D