UKUUG Spring 2009 Conference
24-26 March 2009 in London
Network-Wide System Administration Triggered by RPM
Abstract
The main purpose of the RPM Package Manager, used on the majority of Linux systems, is to (un)install software packages in a controlled way, while keeping track of inter-package dependencies. This is very useful on itself, but this talk is NOT about the normal package management functions of RPM.
The RPM system can also be (ab?)used to automate network-wide system configuration tasks. This is done by creating one or more local RPM packages, that contain scripts and (parts of) configuration files. These special packages do not only contain files, they also ensure that system configuration actions are performed when needed. This is done using the mechanism of trigger-scripts, a powerful feature of RPM that is not very widely used. These scripts are executed (they are "triggered") at the moment other RPM packages are installed or removed. By letting such scripts modify configuration files or by performing other system management actions, RPM can be used as a method to centrally configure systems. Even more important, configuration changes can be propagated through the network by simply updating a configuration package, putting it in a (usually yum) repository and letting it automatically be picked up by the relevant systems. And finally, when a new subsystem is added to some system, it will be configured automatically via the already installed trigger-scripts.
The talk will show some recipes to create the RPM configuration packages. This includes the package definition details (RPM spec file), examples of scripts to change configuration files, and hints for centralizing configuration information for a complete network.
Finally, a technique is shown to centrally control the addition or removal of packages on systems in an existing Linux network. This can be implemented via the same RPM configuration packages, that pull in or push out selected packages using the RPM dependency mechanism.
To summarize: RPM can be used for several network-wide system management tasks. While it is designed for just package management, its more advanced features can be used in a much wider scope. The talk will show code samples for implementing these methods.
Speaker biography
Jos Vos is CEO and co-founder of X/OS Experts in Open Systems BV. He has 20+ years of experience in research, development and consulting -- mostly relating to UNIX systems software, Internet, and security.
His operating system of choice since 1994 is Linux. In the Linux community he is best known for writing ipfwadm and part of the firewall code in the 2.0 kernel. Using RPM since 1996, he is known to nearly never install software without "RPM-ifying" it. He also participated in the design of RPM's trigger-sripts, later implemented by Red Hat.
His company X/OS delivers open, standards-based solutions and services. Products include Linux consulting and support services, custom-built firewall/VPN appliances with embedded Linux, high-availability cluster solutions and Linux-based Point-of-Sale products.
Slides
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