Chapter 7. Building packages

Table of Contents

1. specfile overview
2. The build header
3. Package declarations
3.1. Python dependency tracking
3.2. The debuginfo subpackage
4. Multilingual package description
5. Miscellaneous headers
6. Build scripts
7. Installation image
8. Install/uninstall scripts
8.1. Script invocation
8.2. Triggers
9. Special requirements of uninstallation scripts and triggers
10. Script packages
11. File manifests
12. Dynamic file manifests
13. Macros
13.1. Defining macros
13.2. Referencing macros
13.3. Removing macros
13.4. Predefined macros
13.5. Advanced macro references
13.6. Conditional text inclusion
13.7. Macro processing order
14. Multiple platform builds
15. Converting RPM specfiles

lpbuild is a tool that creates installable package files. lpbuild reads a package specification file, a specfile, which is a collection of shell scripts and configuration directives that describe the application. The shell scripts take the application's source, compile, and build it, after which lpbuild takes over and generates the package archive files that make up the application, which are then subsequently installed by lpm.

A specfile may contain instructions for creating multiple, related installable packages. It is common to have more than one package file created at the same time. A complex application typically consists of the main package, and additional sub-packages that contain optional components.

lpbuild creates the following files:

The specfile contains fragments of shell scripts that compile and install the application into a temporary staging area, called an installation image (see Section 7, “Installation image”). The specfile also contains additional information about the package that lpbuild needs to know. This chapter describes the format of the specfile.

1. specfile overview

The following sample specfile provides an example of its major components:

Name: testpackage     # Package name.
Version: 1
Release: 1
Source: test-1.tar.gz

Requires: glibc

This is a test package.

%package doc

Documentation for the <b>test</b> package.

%begin build

cc -o hello hello.c

%begin install

%{__make} install DESTDIR="$__installdir"




%files doc

The specfile has a well-defined, structured layout. It begins with the build header section. The build header runs from the beginning of the specfile until the first %package section. The build header provides the general information about this application.

The build header is followed by one or more package declaration sections. Each package declaration begins with the %package line. Simple applications will only one package declaration. Large, complex, applications that consists of a main package, and subpackages, will have additional %package lines, one for each subpackage.

The build header, and the package sections, contain all the information lpbuild needs to begin building the application. After the package sections comes the shell script, or scripts, that actually build the application and install it into a temporary staging area, an installation image tree. The %begin line marks the beginning of each shell script. lpbuild runs the system's shell interpreter to execute the shell script. The shell scripts should unpack the source code, compile it and install it.

Only one %begin section is required, but usually there's more than one. Multiple %begin sections are very useful when developing the specfile itself. The process of building and installing an application is rarely straightforward. It is nearly impossible to create a complete specfile from scratch, in one shot. Multiple %begin sections allow a specfile's construction one step at a time. By default, lpbuild executes each %begin section, one after the other. Optional command line parameters can instruct lpbuild to run only a specific, single, %begin section, allowing individual portions of the overall build script to be debugged, one piece at a time.

The %begin sections are ordinarily scripts, which are executed by /bin/sh, except that lpbuild does macro expansion on each shell script, before it gets executed. Macros, like %{name} are explained later in Section 13, “Macros”.

The specfile ends with one or more file manifest sections. These sections contain an explicit manifest of files that the shell scripts placed in the installation image directory. Although the application gets installed in a separate, dedicated directory, an explicit file list is still required. Furthermore, there will be additional %files sections when subpackages are built. A separate %files section appears for the main package and each subpackage.