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title = "Dockerizing an apt-cacher-ng service"
description = "Installing and running an apt-cacher-ng service"
keywords = ["docker, example, package installation, networking, debian, ubuntu"]
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parent = "engine_dockerize"
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# Dockerizing an apt-cacher-ng service
> **Note**:
> - **If you don't like sudo** then see [*Giving non-root
> access*](../installation/binaries.md#giving-non-root-access).
> - **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:
$ docker build -t eg_apt_cacher_ng .
Then run it, mapping the exposed port to one on the host
$ 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:
$ 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:
$ 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:
$ 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.
$ docker stop test_apt_cacher_ng
$ docker rm test_apt_cacher_ng
$ docker rmi eg_apt_cacher_ng