• Introduction
  • Contributing
  • Issues
• Getting started
  • Installation
  • Quickstart
  • Command-line arguments
  • Persistence
  • Docker Compose
  • Usage
  • Logs
• Maintenance
  • Cache expiry
  • Upgrading
  • Shell Access

Dockerfile to create a Docker container image for Apt-Cacher NG.

Apt-Cacher NG is a caching proxy, specialized for package files from Linux distributors, primarily for Debian (and Debian based) distributions but not limited to those.

If you find this image useful here's how you can help:

• Send a pull request with your awesome features and bug fixes

Before reporting your issue please try updating Docker to the latest version and check if it resolves the issue. Refer to the Docker installation guide for instructions.

SELinux users should try disabling SELinux using the command setenforce 0 to see if it resolves the issue.

If the above recommendations do not help then report your issue along with the following information:

• Output of the docker version and docker info commands
• The docker run command or docker-compose.yml used to start the image. Mask out the sensitive bits.
• Please state if you are using Boot2Docker, VirtualBox, etc.

Automated builds of the image are available in this GitHub repo and is the recommended method of installation.

docker pull ghcr.io/oct8l/apt-cacher-ng:latest

Alternatively you can build the image yourself.

docker build -t apt-cacher-ng github.com/oct8l/apt-cacher-ng

Start Apt-Cacher NG using:

docker run --name apt-cacher-ng --init -d --restart=always \
  --publish 3142:3142 \
  --volume ${PWD}/apt-cacher-ng:/var/cache/apt-cacher-ng \
  ghcr.io/oct8l/apt-cacher-ng:latest

Alternatively, you can use the sample docker-compose.yml file to start the container using Docker Compose

You can customize the launch command of Apt-Cacher NG server by specifying arguments to apt-cacher-ng on the docker run command. For example the following command prints the help menu of apt-cacher-ng command:

docker run --name apt-cacher-ng --init -it --rm \
  --publish 3142:3142 \
  --volume ${PWD}/apt-cacher-ng:/var/cache/apt-cacher-ng \
  ghcr.io/oct8l/apt-cacher-ng:latest -h

For the cache to preserve its state across container shutdown and startup you should mount a volume at /var/cache/apt-cacher-ng.

The Quickstart command already mounts a volume for persistence.

SELinux users should update the security context of the host mountpoint so that it plays nicely with Docker:

mkdir -p ${PWD}/apt-cacher-ng
chcon -Rt svirt_sandbox_file_t ${PWD}/apt-cacher-ng

To run Apt-Cacher NG with Docker Compose, create the following docker-compose.yml file

---
version: '3'

services:
  apt-cacher-ng:
    image: ghcr.io/oct8l/apt-cacher-ng:latest
    container_name: apt-cacher-ng
    ports:
      - "3142:3142"
    volumes:
      - apt-cacher-ng:/var/cache/apt-cacher-ng
    restart: always

volumes:
  apt-cacher-ng:

The Apt-Cache NG service can then be started in the background with:

docker compose up -d

To start using Apt-Cacher NG on your Debian (and Debian based) host, create the configuration file /etc/apt/apt.conf.d/01proxy with the following content:

Acquire::HTTP::Proxy "http://172.17.0.1:3142";
Acquire::HTTPS::Proxy "false";

Similarly, to use Apt-Cacher NG in you Docker containers add the following line to your Dockerfile before any apt-get commands.

RUN echo 'Acquire::HTTP::Proxy "http://172.17.0.1:3142";' >> /etc/apt/apt.conf.d/01proxy \
 && echo 'Acquire::HTTPS::Proxy "false";' >> /etc/apt/apt.conf.d/01proxy

To access the Apt-Cacher NG logs, located at /var/log/apt-cacher-ng, you can use docker exec. For example, if you want to tail the logs:

docker exec -it apt-cacher-ng tail -f /var/log/apt-cacher-ng/apt-cacher.log

Before submitting a PR, you can run local tests to verify your changes work correctly:

./test-local.sh

This script will:

• Build the Docker image from your local changes
• Start the apt-cacher-ng service
• Run functional tests to verify package caching works
• Test performance (cache miss vs cache hit)
• Verify health checks and statistics

The project includes comprehensive GitHub Actions workflows that run automatically on PRs:

• Builds the image from PR changes
• Tests actual package downloads through the proxy
• Verifies caching functionality works correctly
• Tests error handling scenarios
• Collects performance metrics and logs

• Tests against different Debian base images (bookworm, bullseye)
• Tests with different apt-cacher-ng versions
• Verifies compatibility with various client distributions (Debian, Ubuntu)
• Tests different package sources and repositories
• Runs performance regression testing
• Scheduled weekly to catch upstream changes

These automated tests ensure that:

• Upstream image changes don't silently break builds
• New changes maintain backward compatibility
• Performance doesn't regress
• The proxy works correctly across different client configurations

Using the Command-line arguments feature, you can specify the -e argument to initiate Apt-Cacher NG's cache expiry maintenance task.

docker run --name apt-cacher-ng --init -it --rm \
  --publish 3142:3142 \
  --volume ${PWD}/apt-cacher-ng:/var/cache/apt-cacher-ng \
  ghcr.io/oct8l/apt-cacher-ng:latest -e

The same can also be achieved on a running instance by visiting the url http://localhost:3142/acng-report.html in the web browser and selecting the Start Scan and/or Expiration option.

To upgrade to newer releases:

1. Download the updated Docker image:

docker pull ghcr.io/oct8l/apt-cacher-ng:latest

2. Stop the currently running image:

docker stop apt-cacher-ng

3. Remove the stopped container

docker rm -v apt-cacher-ng

4. Start the updated image

docker run --name apt-cacher-ng --init -d \
  [OPTIONS] \
  ghcr.io/oct8l/apt-cacher-ng:latest

For debugging and maintenance purposes you may want access the containers shell. If you are using Docker version 1.3.0 or higher you can access a running containers shell by starting bash using docker exec:

docker exec -it apt-cacher-ng bash