Based on quadportnick/cups-airprint.

This Ubuntu-based Docker image runs a CUPS instance that is meant as an AirPrint relay for printers that are already on the network but not AirPrint capable. I'm using it on a Synology NAS because the built in server doesn't work properly with my printers. The local Avahi will be utilized for advertising the printers on the network.

• Switched to ubuntun LTS Can override mirror setting using environment variable MIRROR
• Added ability to install additional drivers

• Move additional drivers installation out of the image build process, Call install_drivers.sh after container launch.

• Can not persists printer configuration because some drivers create configuration outside of CUPS /config.

• Download the drivers and place them under drivers folder
• Create install_PrinterModel_driver.sh in drivers to install it during the build.

• install_brother_lpr_driver.sh Brother Cupswrapper Driver: https://support.brother.com/g/s/id/linux/en/instruction_prn1a.html
• install_canon_UFRII_driver.sh Canon UFRII

• No other printers should be shared under Control Panel>External Devices>Printer so that the DSM's CUPS is not running.
• Enable Bonjour service discovery needs to be marked under Control Panel>Network>DSM Settings

• /config: where the persistent printer configs will be stored
• /services: where the Avahi service files will be generated

• CUPSADMIN: the CUPS admin user you want created
• CUPSPASSWORD: the password for the CUPS admin user

• 631: the TCP port for CUPS must be exposed

CUPS will be configurable at https://[diskstation]:631 using the CUPSADMIN/CUPSPASSWORD when you do something administrative.

If the /services volume isn't mapping to /etc/avahi/services then you will have to manually copy the .service files to that path at the command line.

• CUPS doesn't write out printers.conf immediately when making changes even though they're live in CUPS. Therefore it will take a few moments before the services files update
• Don't stop the container immediately if you intend to have a persistent configuration for this same reason