Installation guide

Chapter 4. Custom Package Management
This chapter provides an overview of how to build packages for successful delivery via Red Hat
Network. Topics covered include why RPM should be used, how to build packages for Red Hat Network,
and how to properly sign packages.
4.1. Building Packages for Red Hat Network
Red Hat Network uses the RPM Package Manager (RPM) technology to determine what software
additions and updates are applicable to each client system. Packages retrieved from Red Hat Network
are usually in RPM format. Entire ISO images, however, are available through the Software tab of the
Red Hat Network website, but are not available in Red Hat Satellite installations. If the Satellite server
has Solaris support enabled, use Red Hat Network Push to upload Solaris packages to custom
channels used by Solaris clients.
RPM is a tool that provides users with a simple method for installing, uninstalling, upgrading, and
verifying software packages. It also allows software developers to package the source code and
compiled versions of a program for end users and developers.
4.1.1. RPM Benefits
RPM provides the following advantages:
Easy Upgrades
Using RPM, you upgrade individual components of a system without completely reinstalling.
When Red Hat releases a new version of Red Hat Enterprise Linux, users do not have to
reinstall in order to upgrade. RPM allows intelligent, fully-automated, in-place upgrades of the
system. Configuration files in packages are preserved across upgrades so users do not lose
customizations. T here are no special upgrade files needed to update a package because the
same RPM file is used to install and upgrade the package.
Package Querying
RPM provides querying options that allows a search through the entire RPM database for all
packages or just for certain files. RPM can also find out what package the file belongs to and
where the package came from. T he files contained in the package are in a compressed archive,
with a custom binary header containing useful information about the package and its contents.
RPM queries the headers quickly and easily.
System Verification
Another feature is the ability to verify packages. If there are concerns that a file related to a
package was deleted, verify the package to check the status of the files it provides. T he
verification notifies you of any anomalies. If errors do exist, the files are reinstalled easily.
Modified configuration files are preserved during reinstallation.
Prist ine Sources
A crucial design goal of RPM is to allow the use of pristine software sources, as distributed by
the original authors of the software. With RPM, the pristine sources can be packaged, along
with any patches that were used, plus complete build instructions. T his is an important
advantage for several reasons. For instance, if a new version of a program is released, it is
unnecessary to start from scratch to make it compile. Looking at the match may allow you to see
what you might need to do. All the compiled-in defaults and changes made to get the software
to build properly are easily visible using this technique.
Chapter 4. Custom Package Management
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