48.2. The Cluster Software Packages Module

This module allows you to install, view, and delete packages on multiple systems at once. If you need to roll out some program to a large number of systems, this module can be used to perform the installation with a single action. The alternative is to install manually on each host or to use NFS to share program files from a single server to multiple clients.

Before reading on, you should have a complete understanding of how the regular Software Packages module works, what packages are, and what they can do. Chapter 12 covers all of these in detail, so read it now. The user interfaces of the two modules are very similar, and the instructions in this chapter assume that you are familiar with the regular module.

One limitation of the Cluster Software Packages module is that the master system and all managed systems must use the same package system, such as RPM, DPKG, or the Solaris package format. This makes sense when you think about it because there is no way that a single package file of a specific type can be installed on multiple systems if some of them do not support that packaging format. If the hosts on your network use different package formats, you will need to set this module up once for each format in use, on different hosts.

Only on operating systems that have a supported package system will the module appear. At the time of writing, only RPM, Debian's package format, the Gentoo package format, and the Solaris and SCO OpenServer package systems are supported. Even though the Software Packages module supports a few more formats, they are not currently usable with this package.

The module itself can be found along with the other cluster-related modules in Webmin's Cluster category. Clicking on its icon will bring up the main page, an example of which is shown in Figure 48.1. At the top is a list of icons representing managed servers registered in the module, and below them are forms for searching for and installing packages. The latter forms will only appear if some systems have been registered, however, which will not be the case the first time you use the module.

To speed up searching, the module keeps a list of all the packages installed on the systems that it manages. This means that any packages installed or removed directly on one of those systems without using this module will not be detected until the lists are refreshed. This may cause the module to incorrectly report that a package exists when it really does not or vice versa. To avoid this problem, always use the Cluster Software Packages module to add or delete packages from managed hosts. Or, use the Refresh package lists button (explained later) to update the lists after making direct changes.