Add CUPS print server container for Brother HL-4150CDN

entrypoint.sh

@@ -0,0 +1,110 @@
+#!/bin/sh
+# Startup script for the containerized CUPS print server.
+#
+# Starts the D-Bus system bus, Avahi (mDNS/DNS-SD) and CUPS, then registers
+# the Brother HL-4150CDN queue if it does not exist yet. The CUPS daemon is
+# kept in the foreground so the container lives as long as the print server.
+#
+# Configuration (all optional, via environment):
+#   PRINTER_IP           IP address / host name of the network printer.
+#   PRINTER_URI          Full device URI; overrides PRINTER_IP when set.
+#   PRINTER_PROTOCOL     lpd (default), socket or ipp - used with PRINTER_IP.
+#   PRINTER_NAME         CUPS queue name and advertised (DNS-SD) name.
+#   PRINTER_DESCRIPTION  CUPS Description (lpadmin -D) shown in the web UI.
+#   PPD_FILE             PPD used for the queue.
+set -eu
+
+PRINTER_NAME="${PRINTER_NAME:-HL4150CDN}"
+PRINTER_IP="${PRINTER_IP:-}"
+PRINTER_URI="${PRINTER_URI:-}"
+PRINTER_PROTOCOL="${PRINTER_PROTOCOL:-lpd}"
+PRINTER_DESCRIPTION="${PRINTER_DESCRIPTION:-}"
+PPD_FILE="${PPD_FILE:-/usr/share/cups/model/brhl4150cdn.ppd}"
+
+LOG_PREFIX="[entrypoint]"
+log() { echo "${LOG_PREFIX} $*"; }
+
+# Build a device URI from PRINTER_IP unless an explicit PRINTER_URI is given.
+if [ -z "${PRINTER_URI}" ] && [ -n "${PRINTER_IP}" ]; then
+    case "${PRINTER_PROTOCOL}" in
+        lpd)
+            PRINTER_URI="lpd://${PRINTER_IP}/binary_p1"
+            ;;
+        socket)
+            PRINTER_URI="socket://${PRINTER_IP}:9100"
+            ;;
+        ipp)
+            PRINTER_URI="ipp://${PRINTER_IP}/ipp/print"
+            ;;
+        *)
+            log "unknown PRINTER_PROTOCOL '${PRINTER_PROTOCOL}', defaulting to lpd"
+            PRINTER_URI="lpd://${PRINTER_IP}/binary_p1"
+            ;;
+    esac
+fi
+
+# --- D-Bus system bus -------------------------------------------------------
+mkdir -p /run/dbus /var/lib/dbus
+if [ ! -s /etc/machine-id ] && [ ! -s /var/lib/dbus/machine-id ]; then
+    log "generating D-Bus machine id"
+    dbus-uuidgen > /var/lib/dbus/machine-id
+fi
+if [ ! -S /run/dbus/system_bus_socket ]; then
+    log "starting dbus-daemon (system bus)"
+    dbus-daemon --system --fork
+fi
+
+# --- Avahi / mDNS -----------------------------------------------------------
+mkdir -p /run/avahi-daemon
+if ! pgrep -x avahi-daemon >/dev/null 2>&1; then
+    log "starting avahi-daemon"
+    avahi-daemon --daemonize --no-chroot
+fi
+
+# --- CUPS -------------------------------------------------------------------
+log "starting cupsd"
+/usr/sbin/cupsd -f &
+CUPSD_PID=$!
+
+# Wait until CUPS accepts requests.
+i=0
+while [ "$i" -lt 30 ]; do
+    if lpstat -r >/dev/null 2>&1; then
+        break
+    fi
+    i=$((i + 1))
+    sleep 0.5
+done
+
+# Share printers on the network and allow remote administration.
+cupsctl --share-printers --remote-admin >/dev/null 2>&1 || true
+
+# --- Brother HL-4150CDN queue ----------------------------------------------
+if lpstat -p "${PRINTER_NAME}" >/dev/null 2>&1; then
+    log "printer ${PRINTER_NAME} already exists"
+elif [ -n "${PRINTER_URI}" ]; then
+    if [ -f "${PPD_FILE}" ]; then
+        log "adding printer ${PRINTER_NAME} -> ${PRINTER_URI}"
+        lpadmin -p "${PRINTER_NAME}" -E -v "${PRINTER_URI}" -P "${PPD_FILE}" \
+            || log "warning: lpadmin failed to add ${PRINTER_NAME}"
+    else
+        log "warning: PPD ${PPD_FILE} not found; skipping printer creation"
+    fi
+else
+    log "neither PRINTER_URI nor PRINTER_IP is set; skipping automatic printer creation"
+fi
+
+# Make sure the queue is shared, named for advertising and set as default.
+if lpstat -p "${PRINTER_NAME}" >/dev/null 2>&1; then
+    lpadmin -p "${PRINTER_NAME}" -o printer-is-shared=true -E >/dev/null 2>&1 || true
+    if [ -n "${PRINTER_DESCRIPTION}" ]; then
+        lpadmin -p "${PRINTER_NAME}" -D "${PRINTER_DESCRIPTION}" >/dev/null 2>&1 || true
+    fi
+    lpadmin -d "${PRINTER_NAME}" >/dev/null 2>&1 || true
+    log "queue ${PRINTER_NAME} is shared and set as default"
+fi
+
+log "ready: CUPS on 631/tcp, mDNS on 5353/udp"
+
+# Keep the container running by waiting on cupsd.
+wait "${CUPSD_PID}"