Webmin

From Mandriva Community Wiki

Description

Webmin is a web-based interface that contains multiple modules to assist the administrator to configure and maintain multiple utilities and perform tasks with a comfortable GUI interface. Using pre-configured modules is more limiting than performing the tasks by hand but for administrators that are seeking to do routine maintenance, the interface can help protect against common mistakes and enable maintenance within standard guidelines.

Another advantage within the Webmin interface is that Webmin can be configured to access multiple machines that are linked (called clusters) and perform common tasks on all of the machines at the same time. This includes common functions like installing new software, maintaining access control lists, syncing users and groups across multiple machines, etc. The advantage here is that changes made to one machine are automatically pushed out to the other linked machines with minimal intervention by the administrator. This simplifies the task of maintaining multiple machines that are all running the same software and require similar configurations.

Setting up this requires that webmin be installed on all of the machines that are to be clustered together. Once the software resides on each machine, webmin needs to be configured to see each of the other machines that it will administer. You can do this by opening up the main webmin interface and clicking on the Webmin Servers Index panel under the Webmin tab. You can either browse the network for all webmin servers and add them, or you can manually add the servers and configure the main login on each machine. This does create a possible security issue since if access is obtained to the main administration machine, then access would also be available on the other machines but if users and groups are replicated across all of the machines, most likely access would follow each in turn anyway.

Once the servers have been configured, you can go to the Cluster tab on the Webmin panel. Here you can define Cron jobs that are shared across machines, and install software packages across all machines using the Cluster Software Packages panel. You can also configure a cluster of Webmin servers which allows you to synchronize webmin users and groups across the machines, as well as upgrade webmin software on all machines in the cluster.

The Cluster options on Webmin are technically meant to help administrators maintain multiple servers set up identically to each other in clusters for load balancing and performance reasons. However, there are still advantages to be gained in multiple machine environments even when this is not the case as long as specific things need to be maintained identically on the computers.

Installation and access

This page has been written for Mandriva Linux 2009 Spring. You're welcome to update it if needed and to modify this paragraph then.
In the panel (usually at the bottom of your screen) click on Configure your computer.

Then choose Software management → Install & remove software. In the left rolling list choose "All". Then look for webmin and confirm by the "OK" button. Then close the Software management window, but not Mandriva control center. Inside Mandriva control center, go to System → "Manage system services by enabling or disabling them". On the line "Webmin", click on the "Start" button and wait a few seconds until webmin is marked "running". Then click on "OK" (in the right bottom corner). Now, you can close Mandriva control center if you don't need it for another task.

After that, go to the Application launcher menu → Tools → Webmin.

For some reason, you have to do this twice. Alternatively open your web browser and give the address "https://localhost:10000". Replace "localhost" by the name of your computer if you named it (Configure your computer → Network & internet → Host definitions). You have to accept this suspicious server with no valid certificate. In Konquerror, a new dialog box opens (picture below), in Mozilla Firefox, the question is inside the window (picture not shown).

In Konquerror, choose "Continue", then you have to choose whether to accept that certificate permanently or just for once.

Choose "forever". In Mozilla Firefox, you have to choose "Details" and then say you want to add this site in the list of autorised sites (pictures not shown). Now, whatever your browser, you're asked for a password.

As username, write "root" and give the superuser's password. That's it. The picture below is Webmin homepage.