Fedora, Ant, and Optional Tasks

I've tried to be good.

I've tried a number of times to use the version of ant that Fedora packages up into an RPM from the JPackage repos rather than caving to the temptation to install it myself manually. I also like to use optional tasks like ReplaceRegExp in my scripts to do all sorts of cool things. Of course, I see most of the installation instructions that refer to ant via RPM mention that I need to yum install ant-apache-regexp to get my optional task jars installed for this very nice task. Every time I've tried this, ant yells at me saying that it can't find the taskdef class for ReplaceRegExp.

Huh? But I installed the proper, RPMs...didn't I?

Usually at this point, I fall back to what works and just install ant by hand.

However, I've finally realized why I've had so much trouble with this. There is one additional RPM that should be installed to get the classes that define all the optional tasks for ant called ant-nodeps. Before getting into some background, the way to fix this issue is to yum install ant-nodeps as well as the optional task jars you need.

Tasks are defined in ant via a small class that extends org.apache.tools.ant.Task or some similar class. The Apache team moved to a more separated architecture for the "sanctioned" optional tasks that are provided with the project. All of the optional tasks are now housed in a jar called ant-nodeps.jar in the lib directory under $ANT_HOME. In conjunction with this jar, there are jars that are specific to each of the tasks, such as ant-apache-regexp.jar.

But the separation is fairly hidden on Windows. Basically, when you download the ant distribution and extract it, you get everything. On Linux, the JPackage and Fedora projects split up the components of ant into separate RPMS. I can't say for sure, but it seems this is done because some of the task dependencies in ant are proprietary. Both JPackage and Fedora go to great pains to make sure that they quarantine themselves from proprietary bits, and so they have to split this stuff up a bit more to achieve that.

This being said, RPMs have a mechanism to specify dependencies. Ideally, all of the optional task jars would include ant-nodeps as a dependency. Even if that RPM had proprietary components (which I don't believe it does), the dependency would be noted and the user expected to satisfy this dependency some other way.

I've opened up a bug for this issue.

Comments

Unknown said…
This saved my day! Thank you!
May 18, 2009 9:31 AM
Tony Watkins said…
For Fedora 11 make sure to "yum install ant-commons-net" otherwise builds fail when trying to find
org.apache.tools.ant.taskdefs.optional.net.FTP

Hope that helps someone as I've been looking for quite a while - the commons-net within the shared java folder isn't picked up for some reason.
July 30, 2009 7:25 AM
Martin 'Windgazer' Reurings said…
Thank you!!! I figured out I need some optionals but never would've guessed the correct YUM package if it weren't for you :)
June 08, 2011 4:37 AM
Post a Comment

Popular posts from this blog

Ghetto Cloud Foundry Home Lab

Image
Over the past few months, I've been cobbling together my own Lab to be able to gain experience with Cloud Foundry.  Sure, I could have gone the much simpler route of bosh-lite , but I wanted to get a broader set of experience with the underlying IaaS layer in conjunction with working with Cloud Foundry. My lab hardware was purchased from various places (eBay, Fry's, etc) when I could get deals on it. Rocking the Ghetto Lab At a high level, the hardware looks like this: Machine CPU Memory Storage Notes HP Proliant ML350 G5 2x Intel Xeon CPU E5420 @ 2.50GHz 32 GB (Came with some disks, but mostly unused) vSphere Host 1, Added a 4 port Intel 82571EB Network Adapter HP Proliant ML350 G5 2x Intel Xeon CPU E5420 @ 2.50GHz 32 GB (Came with some disks, but mostly unused) vSphere Host 2, Added a 4 port Intel 82571EB Network Adapter Whitebox FreeNAS server Intel Celeron CPU G1610 @ 2.60GHz 16 GB 3x 240GB MLC SSDs, in a ZFS stripe set, plus spinning d
Read more

Using Snapshot Isolation with SQL Server and Hibernate

In the course of working on some deadlock issues, I found that MS SQL Server exhibits some unexpected (to me, at least) locking behaviors that can affect performance and cause deadlocks. In the end, I found that SQL Server provides an isolation level called Snapshot isolation which removes the need for locks on rows and removes lock contention. To use this isolation level, you need to execute the following SQL on the database that you want to use the isolation level with (replacing MyDatabase with your database name, of course): ALTER DATABASE MyDatabase SET ALLOW_SNAPSHOT_ISOLATION ON ALTER DATABASE MyDatabase SET READ_COMMITTED_SNAPSHOT ON Next, you need to modify your hibernate.cfg.xml file to add a property to tell Hibernate to use the Snapshot Isolation level: <!-- The 4096 isolation level is the setting to use with the jTDS or Microsoft JDBC drivers --> < property name =”hibernate.connection.isolation”>4096</property> Snapshot isolation is not a panacea
Read more