Changed to Alpine base and removed Brother drivers. Generic postscript

works just fine.

root/root/printer-update.sh

@@ -1,5 +1,5 @@
-#!/bin/bash
-inotifywait -m -e close_write,moved_to,create /etc/cups | 
+#!/bin/sh
+/usr/bin/inotifywait -m -e close_write,moved_to,create /etc/cups | 
 while read -r directory events filename; do
 	if [ "$filename" = "printers.conf" ]; then
 		rm -rf /services/AirPrint-*.service

root/root/run_cups.sh

@@ -3,18 +3,19 @@ set -e
 set -x
 
 if [ $(grep -ci $CUPSADMIN /etc/shadow) -eq 0 ]; then
-    useradd -r -G lpadmin -M $CUPSADMIN 
+    adduser -S -G lpadmin --no-create-home $CUPSADMIN 
 fi
 echo $CUPSADMIN:$CUPSPASSWORD | chpasswd
 
 mkdir -p /config/ppd
 mkdir -p /services
+rm -rf /etc/avahi/services/*
 rm -rf /etc/cups/ppd
 ln -s /config/ppd /etc/cups
-if [ ls /services/*.service ]; then
+if [ `ls -l /services/*.service 2>/dev/null | wc -l` -gt 0 ]; then
 	cp -f /services/*.service /etc/avahi/services/
 fi
-if [ ! -f /config/printers.conf ]; then
+if [ `ls -l /config/printers.conf 2>/dev/null | wc -l` -eq 0 ]; then
     touch /config/printers.conf
 fi
 cp /config/printers.conf /etc/cups/printers.conf