Red Hat Enterprise Linux 5 Administration Unleashed

Installing Software 127Finding the SoftwareBefore learning how to install and maintain RPM packages, you need to know where tofind the packages. With an enterprise system, it is crucial to only install software from areliable source. In the case of Red Hat Enterprise Linux, the trusted source is straight fromRed Hat or a certified software partner or from a Red Hat certified ISV. If you are installingcustom software built inside your company, be sure it goes through testing beforeinstalling it on production systems. Installing software from other sources is most likelynot supported by your Red Hat Enterprise Linux support contract.NOTEFor more information on downloading software directly from Red Hat, refer to Chapter 3.For information on software from other vendors, contact the vendor directly for Linuxversions of their software.Installing SoftwareInstalling an RPM package can be done via the command line or a graphical program.Because some systems such as servers do not always have a graphical desktop installed, itis important to learn at least the basics of how to use the command-line version of RPM.The command is simple to remember: It is the rpm command.5NOTERoot access is required when installing, upgrading, or removing a package with therpm command.Before installing any software, confirm that it was packaged by a trusted source and hasnot been altered since the trusted source built it. This process is done by checking theGPG signature of the package.First, as the root user, import the GPG signature of the trusted party with the rpm --import command, where is the file containing the key. If you do not knowwhere to securely obtain the key file, ask your trusted RPM source.NOTEKey files for software distributed by Red Hat can be found in the root directory of thefirst installation CD:RPM-GPG-KEY-fedoraRPM-GPG-KEY-fedora-testRPM-GPG-KEY-redhat-auxiliaryRPM-GPG-KEY-redhat-betaRPM-GPG-KEY-redhat-formerRPM-GPG-KEY-redhat-release