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CALL FOR DEVELOPERS version 2.0: I made a configuration mistake on mail filters and I wouldn't read many github notification for the past year, so I might not have read help offers. Now my filters are properly configured.

docker-rpm-builder once was quite relevant to my daily job, so I took the time to write and support it. But it is less and less relevant to me, and it requires constant maintenance (new distros come, old distros go, features are requested, et cetera). I would appreciate some help. Write a response to #51 and become a developer!

IMPORTANT: Docker has changed the distribution repos (both APT and YUM) for its packages. See the updated instructions and repos at The new free package is called docker-ce.

IMPORTANT: The APT and YUM repos have changed! Check the new URLs down there!

IMPORTANT: since 1.33, docker-rpm-builder won't force a dependency on a specific docker package, you must install a docker distribution yourself - see prerequisites.

See the News Page for all the latest news.

See also FPM within Docker - an alternative way of building RPMs and DEBs that could make things even easier for you.


docker-rpm-builder is got a number of faithful users and followers; now you can donate to the project, not in the form of money (maybe I'll start accepting some BTC in the near future, but not right now) but in the form of goods; if you find this project useful and you'd like to reward me for my work, you can buy me something from my Amazon wish list.

Table of Contents

For whom is this software designed?

If you already know a bit about RPM packaging, and you're quite confident reading or writing a specfile, either because you need to (e.g. you've got a package that needs very fine tuning) or because you must (e.g. you need your package to work in existing distributions' workflows where a .src.rpm and a specfile are required).

If you just need to package your software in an RPM and don't care too much about conventions, fine tuning, ecc, take a look at FPM within Docker. It'll make your life easier without much fuss.


If you think that:

  • using plain rpmbuild is painful because it requires you to setup a server/vm with the same OS as the build target and then transfer your development code, then reset the build environment to prevent leftovers to alter your future builds, and/or
  • mock could be better because a) it's a complex piece of software that makes debugging failed builds a bit hard, b) sometimes produces errors which are not so easy to understand without digging into its source code, and c) is very hard to run on non-RHEL/Centos/Fedora host distros, and/or
  • hosted build systems like copr or OBS feel slower or simply too complex for the task at hand

then you're in the right place.

Basically, docker-rpm-builder is an ecosystem comprising a way to run rpmbuild inside docker-based containers. Both the tool and a basic set of target build images is included.

Key features

  • Works on any host distribution that supports docker.
  • It's very small and hackable. Take a look at the source code: making modifications is trivial.
  • Can build straight from the source directory without an intermediate .src.rpm
  • It supports a basic templating system for specfiles, which is especially useful in CI contexts.
  • It lets you spawn an interactive shell if the build fails, in the very place where it fails
  • If you use a precise build image and hold all build dependencies within, your builds will be highly reproducible.
  • Cache build dependencies; don't re-download unless your spec changes.
  • The root filesystem is fully writable, letting you install to the 'real' target directory and moving to $RPM_BUILD_ROOT at the end of the build - that's very useful for compiled software that doesn't support PREFIX and after-install relocation properly. Such writes are not persisted within the build image,


  • Currently limited to x86_64 for both host and target. That's a docker limitation which is unlikely to go away soon. 32 bit container images for Docker do exist, but they're considered unsupported by this tool.

Required knowledge

You should have a vague idea of what docker is and you should already know how to build an RPM - see to Maximum RPM and other documentation from Fedora HowTO / RPM Guide.



IMPORTANT: A Docker distribution is required in order to use this tool. I recommend using the latest stable docker-ce RPM or DEB, use prebuilt packages package from or; just follow the official install instructions.

At the dawn of this tool, I tried to make it work with any version of docker that would come from the distributions' repository or from official repository. This proved to be quite troublesome, but at the same time, different distributions are repackaging the docker CLI and daemon in different ways, and users have different priorities. So, since version 1.33 docker-rpm-builder no longer forces a dependency on any docker package on your system. Feel free to use whatever docker version you like; just be aware that I usually test docker-rpm-builder using the official docker-ce packages.

Python 2.7, bash, and wget should be installed on your system as well. If you're using a packaged version, the package will take care of that.

Please note: docker runs on the host system; it is irrelevant whether the target distribution would be able to run docker - in fact you can build Centos/RHEL 5 and 6 packages perfectly.

See the section below for details on some post-install actions for docker.

Docker configuration

If docker is already up and running on your system, you probably need to do absolutely nothing else.

Otherwise, if it's your first time with docker, here's a checklist:

  • Verify you've installed a docker distribution - see prerequisites.
  • Verify the docker service is running
  • Verify the docker group exists and your user belongs to it. It is advised not to run docker-rpm-builder as root. The docker package on some recent Fedoras seems to add a dockerroot group instead - it won't do!
  • If you had to add the group, verify you've restarted the docker service after such addition
  • Verify you've logged out+in after adding your user to the group
  • If you get strange errors, try checking whether SELinux is enabled, and try disabling it to see if the situation changes. As of 1.36, docker-rpm-builder should be compatible with SELinux, but it wasn't thoroughly tested.
  • Verify your disk has enough free space

CentOS 7.x / RHEL 7.x

CentOS 6 / RHEL 6 support for docker-rpm-builder has been discontinued along docker's own support. I'm sorry. If you really need to use such distros, you can try the source install described below, along with docker 1.7.



Now, just:

yum install docker-rpm-builder

And you're done; if you haven't already done so, check the docker configuration section, then launch the test suite

Support plan

I plan to support the latest CentOS/RHEL stable.


Use this yum repository:


dnf install docker-rpm-builder

And you're done; if you haven't already done so, check the docker configuration section, then launch the test suite

Support plan

I plan to support the latest two Fedora releases,unless something bad happens (i.e. the official docker-package is not released anymore for the older fedora), so currently fc26 and fc27 are supported.

Debian Jessie + Stretch

First, you should make sure that Bintray's package signing key properly installed and configured for apt:

curl | sudo apt-key add -

And you should make sure the apt-transport-https package is installed.

Then, pick the repo for your distribution - see below - and save it as /etc/apt/sources.list.d/docker-rpm-builder.list

deb jessie main


deb jessie main

Now you're ready to

apt-get update
apt-get -y install docker-rpm-builder

And you're done; if you haven't already done so, check the docker configuration section, then launch the test suite

Support plan

I plan to support the latest stable Debian release. When a new release comes out, I'll support the oldstable for a few months before dropping it.

Ubuntu (multiple releases)

There're repositories for various Ubuntu versions.

First, you should make sure that you've got Bintray's package signing key properly installed and configured for apt:

curl | sudo apt-key add -

And you should make sure the apt-transport-https package is installed.

Then, pick the repo for your distribution - see below - and save it as /etc/apt/sources.list.d/docker-rpm-builder.list


deb trusty main


deb xenial main


deb artful main

Now you're ready to

apt-get update
apt-get -y install docker-rpm-builder

And you're done; if you haven't already done so, check the docker configuration section, then launch the test suite

Support plan

I plan to support the latest Ubuntu LTS as well as the latest-and-greatest Ubuntu release. Whenever a new version comes out there'll be probably be some months of overlapping support, and I'll probably choose to support older LTSes for more time than "standard" releases (e.g. I don't plan dropping Ubuntu 14.04 support for the whole 2016, even though 16.04 is scheduled for April 2016)

Arch Linux

There is a third-party maintained package for Arch Linux in the AUR. To install it, simply use an AUR helper like yaourt (see also for a list of other AUR helpers). For installing via yaourt, just do as normal user (you should have sudo installed and configured to be able to call pacman):

yaourt --noconfirm docker-rpm-builder

And you're done; if you haven't already done so, check the docker configuration section, then launch the test suite

Support plan

I only support installing packages with yaourt (and with makepkg directly). If it won't install with your AUR helper, try makepkg first before filing a bug request.

Other distributions and OSX - installing straight from source

  • Check the prerequisites and the docker configuration sections.
  • make sure you've got python 2.7 and virtualenv available on your system.
  • make sure you've got wget.
  • clone this repository. Pick the v1 branch, which is where I keep stable releases.
  • run make. You can pass the VIRTUALENV variable to tell make which virtualenv executable to use (e.g make VIRTUALENV='virtualenv -p /usr/bin/python2.7')
  • devenv/bin/docker-rpm-builder will contain the docker-rpm-builder executable.
  • Run the integrated test suite; see next section.

Test everything works!

docker-rpm-builder features an integrated test suite. Run:

docker-rpm-builder selftest

It requires an Internet connection and may take a bit of time for the first run, since it will be downloading a minimal image.

If you want to be extra-sure everything is fine, run:

docker-rpm-builder selftest --full

It will take a really long time to run, especially on your first time.


Building a binary RPM straight from a directory

You should have a source directory that contains:

  • either a .spec file or a .spectemplate file
  • any file that is set as SourceX and PatchX in the spec file ( if any of your SourceX or PatchX files are URLs, you can use the --download-sources option if the files are not already there.)

Then, you should pass a source directory, which will be bind-mounted straight to %{_sourcedir} inside the build container (e.g. /root/rpmbuild/SOURCES on RHEL7 ). You can access such directory straight from your specfile. The source directory is mounted read-only to prevent accidental modifications during the build phase.

If you pass --download-sources the URL sources will be downloaded in such directory, so be sure to set the proper ignores for it in your revision control system.

Of course, you should tell the tool which build image you'd like to use; that's the image where the build will happen. I've baked some prebuilt images, but you should feel free to create your own, since that's the purpose of this tool.

And you should tell the tool which target directory you'd like to use for rpm output; this directory will be bound straight to %{_rpmdir} inside the build container, so mind that if your build process does something strange with it, files can be deleted. If the target directory doesn't exist it will be created.


docker-rpm-builder dir --download-sources alanfranz/drb-epel-5-x86-64:latest . /tmp/rpms

This command will build straight from current dir with the alanfranz/drb-epel-5-x86-64:latest image and output the RPMs you requested in /tmp/rpms.

There're further options to explore: just type

docker-rpm-builder dir --help

To see everything.

URL-based source/patch downloading, shell spawning on build failure, signing, and always updating the remote images are all supported scenarios.

See example/from_dir for a full example of building with a spectemplate from a directory.


The spectemplate approach prevents you from editing the .spec file (or creating a new one) for each build; inside your .spectemplate, just define substitution tags, which are names between @s, e.g.


If there's an environment variable called BUILD_NUMBER when you build your project, such variable will be substituted straight into your spec. This is especially useful in an CI server which builds your packages. See the examples section as well.

Please note: you can't have both a .spec and a .spectemplate in your source directory. That will cause an error.

Spectemplates are automatically compiled when using the dir command, but can be manually generated with the genspec command (see below).

Manually generating specfile to enable caching of build dependencies

Take a look at example/from_remote_source - the whole idea is:

  • create a Dockerfile with your build image. It should inherit from your build platform, add the .spec you're generating in the step below, and call yum-builddep on it.
  • In the main directory, create a Makefile (or a shell script) which creates the .spec from the spectemplate into the build-image directory and then builds the docker image. In this phase, you should complete your spectemplate variables with static values which are not taken from your build environment, because they're used for caching: the genspec command won't overwrite the generated .spec if it's identical to the existing one, and docker won't build again an image if the input files and the Dockerfile are identical; hence, the build-image will be rebuilt only if you change your spectemplate or you modify your Dockerfile.
  • Once you've built the build-image, use it with the dir command (or even the srcrpm command if you prefer, but in such case you can skip the templating-related part altogether) - this time let the build system set the environment variables!
  • If your BuildRequires depends on template variables, you shouldn't use this method.

Rebuilding a source RPM

Rebuilding a .src.rpm file is supported as well. Just check the command:

docker-rpm-builder srcrpm --help

Verification of the .src.rpm signature, signing, spawning a shell on failure and always updating the build image are all supported scenarios.

Chainbuild: build both a source and a binary rpm

I recommend you start building your package with the dir option, then switch to this command for production builds where you'd like to produce a source rpm (for future reference) as well as a binary, in a single shot.

docker-rpm-builder chainbuild --help

Options and flags are very similar to the dir command.

For documentation, see the help included in the source:

Build images

Build images are nothing esoteric. They're just plain OS images with a set of packages, settings and maybe some macros which are needed to perform a build and/or to sign packages. See the next section for some examples.

In order to use an image for building an RPM:

  • rpmbuild must exist in path
  • yum-builddep must exist in path and accept a .spec file or a .src.rpm as input
  • commands must be able to complete without interaction - consider using a custom yum.conf with main->assumeyes=1 and be sure all public keys for your repositories are installed.
  • if you want to sign packages, make sure you install gnupg 1.4 and that the rpmsign executable is available. Also, set a proper %__gpg_sign_cmd macro in /etc/rpm (see existing images).
  • any other build dependencies should be there, but if your package doesn't build because it's missing something else then the proper thing to do is probably add an entry to BuildRequires in the spec file.
  • make sure the commands find stat sort uniq which are available

Prebuilt images

There are some prebuilt configurations for Centos+EPEL and Fedora at; those are available on my docker hub page as well, so they can be used immediately out of the box.


  • if you're used to mock, the build system is a bit different, mocks seems to employ different defaults and has different macros, sometimes a build working with mock may fail with docker-rpm-builder. AFAICU it's one of mock's own strange behaviours; docker-rpm-builder seems actually more similar to the 'real' rpmbuild.
  • dns defaults to public ones, usually Google ones on docker-ce default options. Since you can just pass arbitrary docker options, pass --dns and/or set your internal DNS in the docker config file if you need to access internal repositories.
  • If you're auto-downloading remote files: GitHub hosted files (i.e. releases) throw an HTTP 403 Forbidden when used with the HTTP HEAD method, which in turn is what wget --timestamping is used. Great for caching, but currently dysfunctional. Use a github archive from a tag (e.g. ) to work around this issue until is fixed upstream.


If there's anything you'd like to discuss, feel free to open an issue or drop me an email at .


To all the people who gave me feedback or contributed to this project, in no special order:

  • Brian Lalor
  • Tobias Widén
  • Romain P
  • Pavel Borzenkov
  • Peter Williams
  • Marco Nenciarini

TODOS and ideas

  • Remove wget dependency
  • Speed up via something like nosync
  • Speed up by allowing to mount a yum cache directory


This project is not affiliated, sponsored or endorsed by neither Fedora, RedHat or Docker Inc.