50.1. The Cluster Webmin Configuration Module

Before reading this chapter, you should be familiar with Webmin's cluster management capabilities, explained in the introduction to Chapter 48. All the modules in the Cluster category make use of the Webmin Servers Index module and RPC to control other systems. You should read Chapters 51 and 52, which cover the Webmin Configuration and Webmin Users modules, respectively, as this one can be used to perform many of the same tasks across multiple systems.

The Cluster Webmin Configuration module really has two purposes: the management of Webmin users and groups across on multiple systems, and the installation and removal of modules and themes. If your network has multiple Webmin servers, this module can be very useful for keeping their user lists and user access control settings synchronized. It also provides an easy way to roll out a new module to a large number of servers at once.

Like the other cluster modules covered in Chapters 48 and 49, this one keeps lists of modules, themes, users, and groups from each managed server on the master system. This speeds up searching, but creates the potential for inconsistencies between how the master thinks the other systems are configured and how they really are. For example, if you install a module on or upgrade a managed host, the master system will not know about it until it is manually refreshed, as explained in Section 50.10 “Refreshing User and Module Lists”.

When you click on the module's icon under the Cluster category on Webmin's main menu, the main page shown in Figure 50.1 will be displayed. At the top is a table of icons, one for each of the managed servers. Under each icon is the version of Webmin that is currently running, determined when it was added to the module or last refreshed. Assuming that you have some servers listed, below them are forms for editing and adding users and groups, followed by more forms for installing and finding modules and themes.