# Containerfile for a CUPS print server sharing a Brother HL-4150CDN over
# IPP/AirPrint. Build with Podman:
#
#   podman build -t printserver:latest .
#
# Run with host networking so mDNS (Avahi) can advertise the printer. The
# printer is described by environment variables:
#
#   podman run --rm --network host \
#     -e PRINTER_IP=192.168.100.7 \
#     -e PRINTER_NAME=HL-4150CDN \
#     --name printserver printserver:latest
#
# PRINTER_URI can be used instead of PRINTER_IP for full control:
#
#   -e PRINTER_URI=lpd://192.168.100.7/binary_p1
#
# The HL-4150CDN emulates BR-Script3 (PostScript 3). Jobs are converted to
# PostScript inside CUPS and forwarded to the printer unchanged; the official
# BR-Script3 PPD turns the queue's options (tray, duplex, colour, ...) into
# PostScript "setpagedevice" instructions. No Brother vendor binaries or 32-bit
# libraries are involved.
FROM debian:bookworm-slim

ENV DEBIAN_FRONTEND=noninteractive

# --- Task 3.1: base system, CUPS, Avahi, DBus and conversion filters -------
# cups-filters provides the PDF/PWG/URF -> PostScript filters used for
# driverless clients (AirPrint/IPP Everywhere). Ghostscript and Poppler supply
# the underlying converters, openssl is used by the entrypoint to generate the
# IPPS certificate that AirPrint clients (macOS/iOS) validate.
RUN apt-get update \
    && apt-get install -y --no-install-recommends \
        cups \
        cups-client \
        cups-filters \
        avahi-daemon \
        avahi-utils \
        libnss-mdns \
        dbus \
        procps \
        curl \
        ghostscript \
        poppler-utils \
        ca-certificates \
        openssl \
    && rm -rf /var/lib/apt/lists/*

# --- Task 3.2: install the BR-Script3 PostScript PPD -----------------------
# The PPD encodes every device option (paper source, duplex, colour/mono,
# media type, toner save, resolution, secure print) as PostScript
# "setpagedevice". CUPS's pstops filter injects the selected option code and
# the PPD's JCL entries wrap the job in PJL for the printer.
# The whole assets tree is copied because the directory name contains a space,
# which some COPY implementations cannot quote.
COPY assets /tmp/assets
RUN install -m 0644 \
        "/tmp/assets/Brother HL-4150CDN/ppd/BR4150_2.PPD" \
        /usr/share/cups/model/BR4150_2.PPD \
    && test -s /usr/share/cups/model/BR4150_2.PPD \
    && rm -rf /tmp/assets \
    && rm -f /etc/cups/printers.conf /etc/cups/printers.conf.O

COPY cupsd.conf /etc/cups/cupsd.conf

# CUPS needs the runtime directories to exist in the image.
RUN mkdir -p /run/cups /run/dbus /run/avahi-daemon /var/spool/cups /var/log/cups

# --- Task 3.5: startup script ----------------------------------------------
COPY entrypoint.sh /usr/local/bin/entrypoint.sh
RUN chmod 0755 /usr/local/bin/entrypoint.sh

# --- Task 3.6: exposed ports -----------------------------------------------
# 631/tcp  CUPS administration and IPP
# 5353/udp mDNS / DNS-SD for AirPrint discovery
EXPOSE 631/tcp
EXPOSE 5353/udp

ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]