Docker CUPS print server for Canon LBP-1120 printers with Avahi mDNS auto-discovery

A dockerized CUPS (Common Unix Printing System) server specifically configured for Canon LBP-1120 laser printers with automatic network discovery via Avahi.

Table of Contents

• Overview
• Features
• Quick Start
• Configuration
• Management Commands
• Advanced Usage
• Troubleshooting
• Technical Details
• About CUPS and Avahi

Overview

This project provides a ready-to-use Docker container that runs a CUPS print server with pre-installed Canon CAPT drivers for the LBP-1120 printer. The container includes Avahi daemon for automatic printer discovery on your local network, making it easy to set up network printing for this older Canon laser printer model.

Supported Platforms: Linux (x86_64), macOS (with Docker Desktop)

Features

• CUPS server in a lightweight Docker container
• Canon LBP-1120 printer support with CAPT drivers pre-installed
• Avahi daemon for automatic network discovery (mDNS/Bonjour)
• Web interface for printer management at http://localhost:631
• Optimized settings for monochrome printing with enhanced black output
• Automatic printer configuration on first run
• Persistent configuration support via volume mounts

Quick Start

Prerequisites

• Docker installed on your system (Install Docker)
• Canon LBP-1120 printer connected to the network or USB
• Printer IP address (if using network connection)

1. Build the Container

docker build -t lbp-1120-cups .

2. Configure Printer Connection

Before running the container, edit start.sh to set your printer's IP address:

# Change this line in start.sh:
lpadmin -p CanonLBP-1120 -E -v socket://0.0.0.0 ...
# To your printer's IP, for example:
lpadmin -p CanonLBP-1120 -E -v socket://192.168.1.100 ...

3. Run the Container

docker run \
    -d \
    -p 631:631 \
    -p 5353:5353 \
    -v /var/run/dbus:/var/run/dbus \
    --name lbp-1120 \
    lbp-1120-cups

For USB connection, add the device mapping:

docker run \
    -d \
    -p 631:631 \
    -p 5353:5353 \
    -v /var/run/dbus:/var/run/dbus \
    --device=/dev/usb/lp0 \
    --name lbp-1120 \
    lbp-1120-cups

4. Access the Web Interface

Open your browser and navigate to: http://localhost:631

Default credentials: root / root (if prompted)

Configuration

Port Mapping

Port	Protocol	Purpose
631	TCP	CUPS web interface and IPP (Internet Printing Protocol)
5353	UDP	Avahi mDNS for printer discovery

Volume Mounts

Host Path	Container Path	Purpose
/var/run/dbus	/var/run/dbus	Required for D-Bus communication between services
(optional) /path/to/config	/etc/cups	Persist CUPS configuration between container restarts

Default Printer Settings

The container automatically configures the Canon LBP-1120 with these optimized settings:

• Printer Name: CanonLBP-1120
• Color Mode: Monochrome
• Enhanced Black Printing: Enabled
• Skip Blank Pages: Enabled
• Default Location: Kitchen (configurable in start.sh)
• Connection Protocol: Socket (AppSocket/JetDirect)

Customizing Printer Settings

You can modify printer settings in start.sh before building:

# Change printer location
lpadmin -p CanonLBP-1120 -L "Office" ...

# Change printer IP address
lpadmin -p CanonLBP-1120 -v socket://192.168.1.100 ...

# Modify printer options
lpadmin -p CanonLBP-1120 -o Color=Mono -o CNSkipBlank=ON ...

Management Commands

View Container Status

docker ps | grep lbp-1120

View Logs

docker logs lbp-1120

Stop the Container

docker stop lbp-1120

Restart the Container

docker restart lbp-1120

Remove the Container

docker stop lbp-1120
docker rm lbp-1120

Rebuild After Changes

docker stop lbp-1120
docker rm lbp-1120
docker build -t lbp-1120-cups .
docker run -d -p 631:631 -p 5353:5353 -v /var/run/dbus:/var/run/dbus --name lbp-1120 lbp-1120-cups

Advanced Usage

Using Docker Compose

Create a docker-compose.yml file:

version: '3.8'

services:
  cups:
    build: .
    container_name: lbp-1120
    ports:
      - "631:631"
      - "5353:5353"
    volumes:
      - /var/run/dbus:/var/run/dbus
      - ./cups-config:/etc/cups  # Optional: persist configuration
    restart: unless-stopped
    privileged: false

Then run:

docker-compose up -d

Persistent Configuration

To preserve printer settings between container restarts:

mkdir -p ./cups-config

docker run \
    -d \
    -p 631:631 \
    -p 5353:5353 \
    -v /var/run/dbus:/var/run/dbus \
    -v $(pwd)/cups-config:/etc/cups \
    --name lbp-1120 \
    lbp-1120-cups

Accessing Container Shell

To troubleshoot or make live changes:

docker exec -it lbp-1120 /bin/bash

Manual Printer Configuration

Inside the container or via web interface:

# List available PPD files
lpinfo -m | grep -i canon

# Check printer status
lpstat -p CanonLBP-1120 -l

# Test print
echo "Test page" | lp -d CanonLBP-1120

# View printer options
lpoptions -p CanonLBP-1120 -l

Multiple Printers

To add additional printers, modify start.sh:

# Add a second printer
lpadmin -p CanonLBP-1120-Office -E \
    -v socket://192.168.1.101 \
    -P /usr/share/ppd/CNCUPSLBP1120CAPTJ.ppd \
    -L "Office" \
    -o Color=Mono -o CNEnhanceBlkPrt=ON -o CNSkipBlank=ON

Troubleshooting

Printer Not Detected

1. Verify printer is powered on and connected

   ping 192.168.1.100  # Use your printer's IP

2. Check container logs for errors

   docker logs lbp-1120

3. Verify printer IP address in start.sh

   grep "socket://" start.sh

4. Check firewall settings

   # On Linux
   sudo ufw status
   sudo ufw allow 631/tcp
   sudo ufw allow 5353/udp

5. Test printer connection manually

   docker exec -it lbp-1120 /bin/bash
   telnet 192.168.1.100 9100  # AppSocket port

Cannot Access Web Interface

1. Confirm container is running

   docker ps | grep lbp-1120

2. Check port binding

   docker port lbp-1120

3. Verify no port conflicts

   # On Linux/macOS
   lsof -i :631
   # Or
   netstat -an | grep 631

4. Try accessing with explicit localhost

   • http://127.0.0.1:631
   • http://localhost:631

5. Check browser security settings

   • Some browsers may block self-signed certificates
   • Try using a different browser or incognito mode

Network Discovery Issues

1. Verify Avahi is running

   docker logs lbp-1120 | grep -i avahi

2. Check mDNS port availability

   # Ensure port 5353 is accessible
   docker exec -it lbp-1120 netstat -an | grep 5353

3. Enable mDNS on your network

   • Ensure your router/firewall allows multicast traffic
   • Check that devices are on the same subnet

4. Test mDNS discovery

   # On Linux/macOS
   avahi-browse -a -t
   # Or
   dns-sd -B _ipp._tcp

Print Jobs Stuck or Failing

1. Check CUPS error log

   docker exec -it lbp-1120 tail -f /var/log/cups/error_log

2. Clear print queue

   docker exec -it lbp-1120 cancel -a -x

3. Restart CUPS service

   docker exec -it lbp-1120 /etc/init.d/cups restart

4. Verify printer PPD file

   docker exec -it lbp-1120 lpstat -p CanonLBP-1120 -l

Container Won't Start

1. Check Docker logs

   docker logs lbp-1120

2. Verify D-Bus is available

   ls -la /var/run/dbus/

3. Remove and rebuild container

   docker rm -f lbp-1120
   docker rmi lbp-1120-cups
   docker build -t lbp-1120-cups .
   docker run -d -p 631:631 -p 5353:5353 -v /var/run/dbus:/var/run/dbus --name lbp-1120 lbp-1120-cups

USB Connection Issues

1. Find USB device

   lsusb | grep -i canon
   ls -la /dev/usb/

2. Check device permissions

   sudo chmod 666 /dev/usb/lp0

3. Verify device mapping

   docker exec -it lbp-1120 ls -la /dev/usb/

Common Error Messages

Error	Solution
Unable to connect to printer	Check printer IP address and network connectivity
cupsd: Child exited with status 1	Review /var/log/cups/error_log for details
Avahi daemon failed to start	Ensure D-Bus volume is mounted correctly
lpstat: Bad file descriptor	Restart CUPS service inside container
Print job held	Check printer is ready and has paper/toner

Technical Details

Base Image

Built on olbat/cupsd which provides a minimal CUPS installation.

Included Drivers

• cndrvcups-capt_2.71-1_amd64.deb - Canon CAPT driver
• cndrvcups-common_3.21-1_amd64.deb - Common Canon utilities

Service Architecture

• CUPS daemon: Handles print job processing and IPP protocol
• Avahi daemon: Manages network service discovery (mDNS/Bonjour)
• Automatic printer setup: Configures Canon LBP-1120 on first run
• Canon CAPT driver: Proprietary driver for Canon Advanced Printing Technology

File Structure

.
├── Dockerfile                              # Container build instructions
├── start.sh                                # Startup script for services
├── cndrvcups-capt_2.71-1_amd64.deb        # Canon CAPT driver package
├── cndrvcups-common_3.21-1_amd64.deb      # Canon common utilities
└── README.md                               # This file

Supported Canon Printers

While this container is optimized for the LBP-1120, the CAPT drivers support multiple models:

• LBP-1120
• LBP-810
• LBP-1210
• LBP-2900
• LBP-3000
• And other CAPT-compatible models

To use a different model, modify the PPD file path in start.sh:

lpinfo -m | grep -i canon  # List available PPD files

About CUPS and Avahi

What is CUPS?

CUPS (Common Unix Printing System) is a modular printing system for Unix-like operating systems that allows a computer to act as a print server.

Key features:

• Accepts print jobs from client computers via IPP (Internet Printing Protocol)
• Processes print jobs and converts them to printer-specific formats
• Manages print queues and scheduling
• Provides web-based administration interface
• Supports multiple printer drivers and backends

Why use CUPS in Docker?

• Centralized print server for multiple devices
• Isolate printer drivers from host system
• Easy deployment and configuration
• Consistent environment across different hosts

What is Avahi?

Avahi is a system that facilitates service discovery on local networks via the mDNS/DNS-SD protocol suite (also known as Bonjour on macOS).

Key features:

• Automatic network printer discovery
• Zero-configuration networking
• Compatible with AirPrint and Bonjour
• No manual IP address configuration needed on client devices

In this container:

• Publishes the CUPS server on the local network
• Allows devices to discover the printer automatically
• Enables seamless printing from mobile devices and computers

Client Setup

macOS

1. Open System Preferences > Printers & Scanners
2. Click the + button to add a printer
3. The Canon LBP-1120 should appear automatically via Bonjour
4. Select it and click Add

Windows

1. Download and install Bonjour Print Services from Apple
2. Open Control Panel > Devices and Printers
3. Click Add a printer
4. Select the discovered Canon LBP-1120
5. Install drivers when prompted

Linux (Ubuntu/Debian)

# Install CUPS client
sudo apt install cups-client

# Add printer via IPP
lpadmin -p CanonLBP-1120 -E -v ipp://localhost:631/printers/CanonLBP-1120

# Set as default
lpadmin -d CanonLBP-1120

# Print test page
lp -d CanonLBP-1120 /usr/share/cups/data/testprint

iOS/iPadOS

1. Ensure device is on the same network
2. Open any app with print functionality
3. Tap Share > Print
4. Select the Canon LBP-1120 (should appear automatically)

Security Considerations

• The CUPS web interface is accessible without authentication by default
• For production use, consider:
  • Enabling authentication in /etc/cups/cupsd.conf
  • Using reverse proxy with SSL/TLS
  • Restricting network access with firewall rules
  • Running container in isolated network

Example: Enable authentication

# Inside container
cupsctl --remote-admin --remote-any --share-printers

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

Potential Improvements

• Add SSL/TLS support for CUPS web interface
• Support for environment variables for configuration
• Multi-architecture builds (ARM support)
• Healthcheck endpoint
• Support for additional Canon printer models

License

This project uses Canon proprietary drivers. Please ensure compliance with Canon's licensing terms.

Acknowledgments

• Based on olbat/cupsd Docker image
• Canon CAPT drivers from Canon official repositories

Support

For issues and questions:

• Check the Troubleshooting section
• Review container logs: docker logs lbp-1120
• Open an issue on GitHub (if applicable)

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Last Updated: 2025-10-10 Version: 1.0