samba4 with CUPS support for OpenWRT

Note: This is mostly just a reference of how I did it. Feel free to send pull requests with improvements.

Building and installation

# Download the OpenWRT SDK
# (you may need to select a different one, matching your device - the remaining steps are the same for all of them)
wget https://downloads.openwrt.org/releases/19.07.5/targets/ath79/generic/openwrt-sdk-19.07.5-ath79-generic_gcc-7.5.0_musl.Linux-x86_64.tar.xz
tar xvf openwrt-sdk-19.07.5-ath79-generic_gcc-7.5.0_musl.Linux-x86_64.tar.xz
cd openwrt-sdk-19.07.5-ath79-generic_gcc-7.5.0_musl.Linux-x86_64.tar.xz

# Add the package feed
echo "src-git samba4_with_cups https://github.com/krzys-h/openwrt-samba4_with_cups.git" >> feeds.conf.default
# Alternatively, for a local directory:
echo "src-link samba4_with_cups /absolute/path/to/samba4_with_cups" >> feeds.conf.default

# TODO: You have to use the local directory variant and patch the absolute path to python3 makefile in samba4/Makefile ... i can't get the path to work otherwise due to symlinks...

# Update the package index, making sure that we use our version of samba4 rather than the builtin one
# I'm not sure which one would be chosen otherwise
# (note: cups is not packaged in the default repositories at all, so we don't have to worry about it)
./scripts/feeds update -a
./scripts/feeds install -a
./scripts/feeds uninstall samba4
./scripts/feeds install -p samba4_with_cups samba4

# Enable the packages
make menuconfig
# In the UI:
# Network > Printing > cups, set to M (module)
# Network > samba4, set to M (module)
# Select Save and then Exit

# Build
# (this will take a while - it needs to build all dependencies as well)
make -j9 package/cups/compile package/samba4/compile

# Upload to device
scp bin/packages/mips_24kc/samba4_with_cups/* root@openwrt:.

# Install the packages
ssh root@router
opkg remove samba4-libs samba4-server  # if you have the normal version already installed
opkg install libcups_2.3.0-2_mips_24kc.ipk
opkg install cups_2.3.0-2_mips_24kc.ipk
opkg install samba4-libs_4.11.17-1_mips_24kc.ipk
opkg install samba4-server_4.11.17-1_mips_24kc.ipk

# Create the spooler and driver dirs
mkdir -p /srv/samba/print_drivers
mkdir -p /srv/samba/print_spool
chmod 0777 /srv/samba/print_spool

# Go to http://openwrt:631/ and configure your printer. You'll probably want to use the default
# raw queue as routers generally don't have enough processing power to render jobs
# (and we don't install anything else anyway)

# Remember to enable "printer sharing" if you intend to access it from CUPS clients

# Restart smbd after configuring the printer in CUPS. Everything else should be already set up.
/etc/init.d/samba4 restart

# Don't forget to create an user, or reconfigure samba for anonymous access!

Configuring CUPS clients

Configure the printer using the following path: ipp://openwrt:631/printers/printer_name_on_the_server

You have to choose the driver manually.

Configuring Windows clients

You should be able to navigate to \\openwrt and configure the printer using the normal Windows UI

You have to choose the driver manually. In theory it's possible to serve the driver using samba but I couldn't get it to work.

References

https://github.com/TheMMcOfficial/lede-cups https://github.com/openwrt/packages/tree/openwrt-19.07/net/samba4