Populartity of Bodington

Bodington did quite well in a recent report on VLEs with it being used in 8% if institutions questioned. On the publicity front this was been quite good with with being picked up by some other bloggers:

• Alvaro Gregori
• Stuart Yeates
• Stephen Downes

I would be great if some of this interest converted to more people working on the software and deploying it.

Locking down PostgreSQL

In a previous post is noted how to restrict access to a Tomcat installation so that it could only be accessed from the local machine. Here is a little tip for how todo the same thing for PostgreSQL. This increases the security of these applications as you have to posses an account on the local machine to connect to the services. The interfaces that PostgreSQL listens on is configured in a file called postgresql.conf which is often located in /etc/postgresql/ to restrict connections to PostgreSQL add the following line: virtual_host = '127.0.0.1' The restart PostgreSQL: /etc/init.d/postgresql restart You should then be able to check that PostgreSQL is only listening on the local interface with the command: # netstat -tln | grep 5432 which should give you:

tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN

Events and WebServices

My notes from a very quick look at WS-Notifications / WS-Eventing. There are two specs for doing pretty much the same thing. You have something that produces events, for example with a light switch, the events might be light switched on, light switched off. With these specs other systems like the coffee maker (consumers) can register with the producer to receive events when something happens. An example use might be that when the coffee machine starts up it registers with the light switch to receive "on" events. Then when the light switch it turned on it sends an "on" event to the coffee machine so it brews some coffee. The light switch and the coffee machine would have to agree on a message format but the specs define how the registration works and what the outline of the events looks like. The producer looks after the list of consumers that want to be notified of events and when registration happens the consumer tells the producer where events should be sent to. Neither of these specs specify anything about what is in the contents of the notifications. They are similar to event listeners from the Java GUI world. Both the specs came out around 2004:

• - WS-Notifications is the IBM spec (support for brokers, liked to WS-Topics/WS-Resource, more Java focus?, links to Grid? ). http://ifr.sap.com/ws-notification/ws-notification.pdf
• - WS-Eventing is the BEA/Microsoft spec (small/simple). http://ftpna2.bea.com/pub/downloads/WS-Eventing.pdf

Java and HTTPS (Globalsign)

It seems that Java 1.4 doesn't have to Globalsign root certificate installed which means it fails to connect to some Websites using HTTPS. You can grab the certificate from: http://secure.globalsign.net/cacert/root.cacert and then install it with a command like:

keytool -keystore /usr/local/j2sdk1.4.2_07/jre/lib/security/cacerts
-import -file root.cacert -alias globalsign

The standard password is "changeit" and after saying you trust it you should be able to connect to sites through HTTPS that are signed with a globalsign root certificate.

CruiseControl for Bodington and WebLearn

One thing we have had running at Oxford for a little while is an automatic build tool for both WebLearn and Bodington which after each change that is made to the software (each CVS commit ) it attempts to build it. If the build fails due to a compilation error it starts spamming the people involved in the last set of CVS commits until the problem is fixed. This helps to keep the projects buildable all the time. Another benifit is you can also grab a built copy the codebase from the Build Artifacts directory (eg the quickstart WAR). http://dev.weblearn.ox.ac.uk/cruisecontrol/ WebLearn Build (4th October 2005) As you might have guessed from the URL it uses CruiseControl which Java project consiting of the build tool and a webapp to publish everything. Which reminds me the new version of CruiseControl has an RSS publisher so people can keep up to date using a normal feed reader, must upgrade sometime...

ChangeLogs from CVS

One nice thing about CVS is that you can get ChangeLogs between versions for very little work. For example we like to know what have changed between two stable versions of WebLearn (the Oxford deployment of Bodington),at the moment we are going from 2.6.4 to 2.6.5 and there is a nice tool called cvs2cl with which you can query your CVS tree and ask for all the changed between two versions. I build my ChangeLogs with the command:

cvs2cl.pl --delta WebLearn_2_6_4:HEAD -F branch_WebLearn_2_6 -r .

and it will give me all the changes between 2.6.4 and the latest version on the branch called branch_WebLearn_2_6.

Linux Router (WRT54G)

I finally started using my Linksys wireless router (WRT54G) which runs Linux in the form of OpenWRT for my home network. Although nothing much has changed from the service point of view, the laptops still see a wireless access point connected to the internet, it means I can run wondershaper (can't recommend it enough) on it which allows me to keep the ADSL link useful for other people even when I am doing a large downloads/uploads. The only other small change is that it runs a DNS cache so recent lookup should be faster and if does hostname resolution for machines on the lan (192.168.20.1 resolves to router.lan). That was my geeky achievement for the weekend.