6. Building RPMs

Building RPMs is fairly easy to do, especially if you can get the software you are trying to package to build on its own. We assume here that you know how to build software from source. If you don't you probably shouldn't be starting with this document.

The basic procedure to build an RPM is as follows:

Under normal operation, RPM builds both binary and source packages.

6.1. The Spec File

We'll begin with discussion of the spec file. Spec files are required to build a package. The spec file is a description of the software along with instructions on how to build it and a file list for all the binaries that get installed.

You'll want to name your spec file according to a standard convention. It should be the package name-dash-version number-dash-release number-dot-spec. This will ensure that if you install multiple source RPMs for different versions of the same package that at least the spec files remain intact.

Here is a small spec file (eject-2.0.2-1.spec):

Summary: A program that ejects removable media using software control.
Name: eject
Version: 2.0.2
Release: 3
Copyright: GPL
Group: System Environment/Base
Source: http://metalab.unc.edu/pub/Linux/utils/disk-management/eject-2.0.2.tar.gz
Patch: eject-2.0.2-buildroot.patch
BuildRoot: /var/tmp/%{name}-buildroot

The eject program allows the user to eject removable media
(typically CD-ROMs, floppy disks or Iomega Jaz or Zip disks)
using software control. Eject can also control some multi-
disk CD changers and even some devices' auto-eject features.

Install eject if you'd like to eject removable media using
software control.

%setup -q
%patch -p1 -b .buildroot


mkdir -p $RPM_BUILD_ROOT/usr/bin
mkdir -p $RPM_BUILD_ROOT/usr/man/man1

install -s -m 755 eject $RPM_BUILD_ROOT/usr/bin/eject
install -m 644 eject.1 $RPM_BUILD_ROOT/usr/man/man1/eject.1




* Sun Mar 21 1999 Cristian Gafton <gafton@redhat.com> 
- auto rebuild in the new build environment (release 3)

* Wed Feb 24 1999 Preston Brown <pbrown@redhat.com> 
- Injected new description and group.

[ Some changelog entries trimmed for brevity.  -Editor. ]

6.2. The Header

The header has some standard fields in it that you need to fill in. There are a few caveats as well. The fields must be filled in as follows:

6.3. Prep

This is the second section in the spec file. It is used to get the sources ready to build. Here you need to do anything necessary to get the sources patched and setup like they need to be setup to do a make.

One thing to note: Each of these sections is really just a place to execute shell scripts. You could simply make an sh script and put it after the %prep tag to unpack and patch your sources. We have made macros to aid in this, however.

The first of these macros is the %setup macro. In its simplest form (no command line options), it simply unpacks the sources and cd's into the source directory. It also takes the following options:

The next of the available macros is the %patch macro. This macro helps automate the process of applying patches to the sources. It takes several options, listed below:

That should be all the macros you need. After you have those right, you can also do any other setup you need to do via sh type scripting. Anything you include up until the %build macro (discussed in the next section) is executed via sh. Look at the example above for the types of things you might want to do here.

6.4. Build

There aren't really any macros for this section. You should just put any commands here that you would need to use to build the software once you had untarred the source, patched it, and cd'ed into the directory. This is just another set of commands passed to sh, so any legal sh commands can go here (including comments).


Your current working directory is reset in each of these sections to the toplevel of the source directory, so keep that in mind. You can cd into subdirectories if necessary.

The variable RPM_OPT_FLAGS is set using values in /usr/lib/rpm/rpmrc. Look there to make sure you are using values appropriate for your system (in most cases you are). Or simply don't use this variable in your spec file. It is optional.

6.5. Install

There aren't really any macros here, either. You basically just want to put whatever commands here that are necessary to install. If you have make install available to you in the package you are building, put that here. If not, you can either patch the makefile for a make install and just do a make install here, or you can hand install them here with sh commands. You can consider your current directory to be the toplevel of the source directory.

The variable RPM_BUILD_ROOT is available to tell you the path set as the Buildroot: in the header. Using build roots are optional but are highly recommended because they keep you from cluttering your system with software that isn't in your RPM database (building an RPM doesn't touch your database...you must go install the binary RPM you just built to do that).

6.6. Cleaning your system

It's a good idea to always make sure there is a clean build root before building a package a second time on a system. The %clean macro will help with that. Simply put the proper commands there to blow away a former build root. Anal, err, careful folks may want to test that RPM_BUILD_ROOT wasn't set to / before doing something this volatile.

6.7. Optional pre and post Install/Uninstall Scripts

You can put scripts in that get run before and after the installation and uninstallation of binary packages. A main reason for this is to do things like run ldconfig after installing or removing packages that contain shared libraries. The macros for each of the scripts is as follows:

The contents of these sections should just be any sh style script, though you do not need the #!/bin/sh.

6.8. Files

This is the section where you must list the files for the binary package. RPM has no way to know what binaries get installed as a result of make install. There is NO way to do this. Some have suggested doing a find before and after the package install. With a multiuser system, this is unacceptable as other files may be created during a package building process that have nothing to do with the package itself.

There are some macros available to do some special things as well. They are listed and described here:

The biggest caveat in the file list is listing directories. If you list /usr/bin by accident, your binary package will contain every file in /usr/bin on your system.

6.9. Changelog

This is a log of what changes occurred when the package is updated. If you are modifying an existing RPM it is a good idea to list what changes you made here.

The format is simple. Start each new entry with a line with a * followed by the date, your name, and your email address. The date should appear in the same format that is output by:

	date +"%a %b %d %Y"

The rest of the section is a free text field, but should be organized in some coherent manner.