LCFG Core Project

Over the last few years I have been working on (and off) creating a new set of “core” libraries for LCFG. This is now finally edging towards the point of completion with most of the remaining work being related to polishing, testing and documentation.

This project originated from the need to remove dependencies on obsolete Perl XML libraries. The other main aims were to create a new OO API for resources/components and packages which would provide new opportunities for code reuse between client, ngeneric and server.

Over time several other aims have been added:

  • Simplify platform upgrades.
  • Platform independence / portability.
  • Make it possible to support new languages.
  • Ensure resource usage remains low.

Originally this was to be a rewrite just in Perl but the heavy resource usage of early prototypes showed it was necessary to move at least some of the functionality into C libraries. Since that point the chance to enhance portability was also identified and included in the aims for the project. As well as making it possible to target other platforms (other Linux or Unix, e.g. MacOSX), the enhanced portability should make it much simpler and quicker to port to new Redhat based platforms.

The intention is that the new core libraries will be totally platform-independent and portable, for example, no hardwired paths or assumptions that platform is Redhat/RPM (or even Linux) based. The new core is split two parts: C and Perl libraries with the aim that as much functionality as possible is in the C libraries to aid reuse from other languages (e.g. Python).

The aim is that these libraries should be able to co-exist alongside current libraries to ease the transition.

I have spent a lot of time on documenting the entire C API. The documentation is formatted into html and pdf using doxygen, I had not used this tool before but I am very pleased with the results and will definitely be using it more in the future. Although a slow task, documenting the functions has proved to be a very useful review process. It has helped me find many inconsistencies between functions with similar purposes and has led to numerous small improvements.

LCFG Client

The client has been reworked to use new Core libraries. This is where the platform-specific knowledge of paths, package manager, etc, is held.

Resource Support

Format Read Write
Status YES YES
Environment YES YES

There is currently no support for reading header files or source profiles but this could be added later.

There is new support for finding the “diffs” between resources, components and profiles.

Package Support

Format Read Write
rpmcfg YES YES
rpmlist YES YES

There is currently no support for reading package list files but this could be added later.

Remaining Work

There is still work to be done on the top-level profile handling code and the code for finding the differences between resources, components and profiles needs reworking. Also the libraries for reading/writing XML files and Berkeley DB need documentation.

That is all the remaining work required on the “core” libraries. After that there will be some work to do on finishing the port of the client to the new libraries. I’ve had that working before but function APIs have changed, I don’t expect it to require a huge amount of work.

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