Archive for the 'lca2008' Category

Today, 14-Jan-08: Query languages, LDAP, business intelligence and filesystems

I’m going to start regularly writing daily posts about what I did today and the things I found interesting, I’ll at least try anyway.

First up for today is a personal thing, I completed a rather largish Uni assignment today which reminded me of all of the pains that come with C++, but to follow that I returned to working on my filesystem in C, which is just more pain. I got a quick response back, and almost full marks (96%) so I’m happy for all of the time I put in to get it done and how its probably far more complicated than anything else that will be submitted (it used Boost Signals and a whole heap of other things that I don’t think will ever be taught in the subject for a long time). But hey, thats just Uni!

Today I finally managed to get Pentaho, some business intelligence (BI) software, to play nicely with Novell eDirectory’s LDAP interface. I must have missed the option, but Pentaho doesn’t seem to accept anonymous binding to the LDAP server, which means I need to bind as a user. By default our users funnily enough have less access than the anonymous account (which is actually a proxy account with full browse permissions). The solution was simple enough: we shunted our dummy Pentaho user into the same group as the anonymous proxy account and everything worked. So I’ve now got Pentaho using LDAP for authentication (yay!) and a MySQL database to get its role/group permissions. Funnily enough when its all said and done the documentation is pretty close to the mark.

But once I had that I don’t have an ability to manage the groups/roles within Pentaho, so I end up having to write some small PHP to manage that. Luckily I worked on a project a while back that I called “Joomla! Central Management for Users” which basically connected directly to MySQL databases of Joomla! installs and altered the users. I had originally built it with a plugin infrastructure in mind so that I could plug other stuff into it later. Starting this morning it only had a ‘connector’ for Joomla! 1.0 via MySQL and LDAP, now it has one for the Pentaho security tables. This means I can easily copy users from LDAP or Joomla! into Pentaho without too much issues and has a debugged user interface already. But wait theres more!

When I was originally developing the tool I wrote a query language for it. See, SQL is a great language for databases, but its a bit hard to apply in situations where you don’t quite need all of that power. So I wrote my own query language. Its quite simple it can validate simple attributes and allows for set operations within “Sites” (a site is a container for users and groups). So for example I want to see all of the users who are on our web site but not in our LDAP directory:
existsin “Web Sites” and not existsin “LDAP”

Primitive sure, but it because writing a large SQL expression for something simple. I hope to expand on it, but it already does what it needs to do for the time being.

So I’ve covered query languages, LDAP and BI! All I need now is the filesystem news. Today there was a whole heap of fan fare on Slashdot about the ZFS news from Apple, whilst thats cool and all (especially since I don’t mind Apple’s UI), I personally have my own filesystem that I’ve gotten back into to do some work on. It also happens to be a Uni assignment due on Friday! So I’ll be back to working on that and hopefully I’ll have it to a nice stage that I can do some lightening talks at linux.conf.au!

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