Linux RPM Checker

I have been regularly installing Oracle RAC on Linux since 2003. One area that has consistently frustrated me is checking for required RPM packages, particularly in x86-64 environments. In the past the list of packages has often been imcomplete and it has been necessary to consult Oracle documentation, Metalink and the wider internet to arrive at a comprehensive list. To their credit Oracle have tried to address this in Oracle 11.2 where the Oracle Installer now checks for packages at the end of the interview process. In a RAC environment, the CVU can also perform checks prior to installation. Though recent versions of the Oracle database are a great improvement, there are still a few areas of concern including:

Pre-Oracle 11.2 systems. It is still necessary to build older versions of Oracle to test upgrades and to support legacy databases; the new Installer functionality cannot help here
Other products e.g. Enterprise Manager Grid Control which do not include the new Installer functionality yet
Packages are often installed by system administrators as part of a standard build before the Oracle environment is created. Failure to install these packages can result in long and costly delays while the additional packages are added to the standard build.

Another problem is that in x86-64 environments both 32-bit and 64-bit versions of some packages are required.

Within my consultancy business I also have a requirement when generating documentation for a list of required packages and a list of actual packages. These lists are tedious to type in and consequently very error prone.

So I decided to do something about it.

My first approach was to develop an RPM and use the in-built RPM dependency checking algorithm to check versions. It took a while to figure out how to create a spec file for the rpmbuild utility, but eventually I managed to create a package. However, when I tried to extend the package to handle both 32-bit and 64-bit architectures I discovered that there is a fundamental flaw in RPM - it only appears to work for the architecture on which it is created - I could not find a way to specify packages of another architecture (i386 etc) in the requires directive of the spec file. Getting RPM enhanced might be possible, but I have better things to do with my life and there would still be an issue with compatibility on legacy systems.

However, I did manage to find the source files for RPM and discovered that it uses a library function called rpmvercmp to compare first versions and then releases for packages. A quicker option was to convert the C code into Perl. I like Perl because it is usually available on any Unix-based Oracle environment. My Perl skills are not great, but I managed to develop a working comparison algorithm within a few hours.

The next problem was to provide the Perl script with a list of required packages together with their architectures and minimum versions. XML was an obvious choice but I needed to confirm it would work with Perl. In fact there are several XML options with Perl - I originally implemented the utility using the XML::Simple package. However, this meant it was necessary to install the perl-XML-Simple package in order to run the checker, requiring a change control at some sites. I decided this would be an unnecessary restriction, so I rewrote the XML parser components in Perl.

The rpmcheck utility is supplied with a set of XML definition files. Each file is based on:

Oracle product e.g. Grid Infrastructure
Oracle release e.g. 11.2.0.2
Operating system e.g. RHEL5
Architecture e.g x86_64

I think this provides sufficient granularity. At present I have only prepared XML files for a handful of releases - I will expand these as I revisit Linux customers.

If you wish to try these scripts they can be downloaded from my website. Instructions to run the Perl script are included.

The basic procedure is:

Download the files from http:://www.juliandyke.com - files are currently delivered in a zip file (rpmcheck.zip)
Unzip the archive

unzip rpmcheck.zip

Run the checker specifying the appropriate XML file as a parameter. For example:

perl rpmcheck.pl GridInfrastructure-11_2_0_2-RHEL5-x86-64.xml

The script will report if all packages are valid; if not it provide details of expected and actual (if any) versions of the packages.

Further details and sample output can be found here.

The script and XML files can be downloaded directly from here

I would definitely like some feedback on this - hopefully it can be extended to a comprehensive list of environments.