page_title: Dockerizing an apt-cacher-ng service page_description: Installing and running an apt-cacher-ng service page_keywords: docker, example, package installation, networking, debian, ubuntu # Dockerizing an Apt-Cacher-ng Service > **Note**: > - **If you don't like sudo** then see [*Giving non-root > access*](/installation/binaries/#dockergroup). > - **If you're using OS X or docker via TCP** then you shouldn't use > sudo. When you have multiple Docker servers, or build unrelated Docker containers which can't make use of the Docker build cache, it can be useful to have a caching proxy for your packages. This container makes the second download of any package almost instant. Use the following Dockerfile: # # Build: docker build -t apt-cacher . # Run: docker run -d -p 3142:3142 --name apt-cacher-run apt-cacher # # and then you can run containers with: # docker run -t -i --rm -e http_proxy http://dockerhost:3142/ debian bash # FROM ubuntu MAINTAINER SvenDowideit@docker.com VOLUME ["/var/cache/apt-cacher-ng"] RUN apt-get update && apt-get install -y apt-cacher-ng EXPOSE 3142 CMD chmod 777 /var/cache/apt-cacher-ng && /etc/init.d/apt-cacher-ng start && tail -f /var/log/apt-cacher-ng/* To build the image using: $ sudo docker build -t eg_apt_cacher_ng . Then run it, mapping the exposed port to one on the host $ sudo docker run -d -p 3142:3142 --name test_apt_cacher_ng eg_apt_cacher_ng To see the logfiles that are `tailed` in the default command, you can use: $ sudo docker logs -f test_apt_cacher_ng To get your Debian-based containers to use the proxy, you can do one of three things 1. Add an apt Proxy setting `echo 'Acquire::http { Proxy "http://dockerhost:3142"; };' >> /etc/apt/conf.d/01proxy` 2. Set an environment variable: `http_proxy=http://dockerhost:3142/` 3. Change your `sources.list` entries to start with `http://dockerhost:3142/` **Option 1** injects the settings safely into your apt configuration in a local version of a common base: FROM ubuntu RUN echo 'Acquire::http { Proxy "http://dockerhost:3142"; };' >> /etc/apt/apt.conf.d/01proxy RUN apt-get update && apt-get install -y vim git # docker build -t my_ubuntu . **Option 2** is good for testing, but will break other HTTP clients which obey `http_proxy`, such as `curl`, `wget` and others: $ sudo docker run --rm -t -i -e http_proxy=http://dockerhost:3142/ debian bash **Option 3** is the least portable, but there will be times when you might need to do it and you can do it from your `Dockerfile` too. Apt-cacher-ng has some tools that allow you to manage the repository, and they can be used by leveraging the `VOLUME` instruction, and the image we built to run the service: $ sudo docker run --rm -t -i --volumes-from test_apt_cacher_ng eg_apt_cacher_ng bash $$ /usr/lib/apt-cacher-ng/distkill.pl Scanning /var/cache/apt-cacher-ng, please wait... Found distributions: bla, taggedcount: 0 1. precise-security (36 index files) 2. wheezy (25 index files) 3. precise-updates (36 index files) 4. precise (36 index files) 5. wheezy-updates (18 index files) Found architectures: 6. amd64 (36 index files) 7. i386 (24 index files) WARNING: The removal action may wipe out whole directories containing index files. Select d to see detailed list. (Number nn: tag distribution or architecture nn; 0: exit; d: show details; r: remove tagged; q: quit): q Finally, clean up after your test by stopping and removing the container, and then removing the image. $ sudo docker stop test_apt_cacher_ng $ sudo docker rm test_apt_cacher_ng $ sudo docker rmi eg_apt_cacher_ng