Not fully convinced by Maven 2

After several weeks of trying to migrate our build process to Maven 2, we decided to stop due to:

• Incompatibility with WebLogic: we use BEA Weblogic ant tasks that are not compatible with Maven build lifecycle phases. For instance, appc mixes generate-sources, compile and package; for this reason the maven-weblogic-plugin that uses these tasks has same flaw. So if you need to use other Maven plugins you must implement workarounds and attach them to unnatural phases to ensure they get executed before or after appc. See my previous post.
  

• Lack of flexibility: by nature, Maven is not flexible, the only ways to get more flexibility is to use profiles, maven-antrun-plugin or to write your own plugin in java: not really simple nor very productive especially if you need to write simple workarounds. It's strange because there seems to be a growing tendency in open source build tools to enable more flexibility: ant 1.8 feature list includes logic/control flow features from ant-contrib (for, if, while, etc…), gant uses groovy as build scripting language on top of ant, buildr uses Ruby.

• Lack of auditability: with Maven's convenient way to download missing parts and self update, it's difficult to know exactly what was used to build one version of your product. The fact that Maven mixes tool's dependencies of the tool (maven+plugins) and dependencies of the projects being built into one single local repository surely does not help here. it would be better if separation of concerns was implemented in local repository to ensure that the dependencies managed by the developers do not get polluted by dependencies that are out of its control scope.

• Issues are difficult to diagnose: I've got examples about classpath, system properties where it's difficult to find the culprit between Maven, plugins or dependencies.

• Plugins quality ranks from excellent to terrible: this is not a Maven issue by itself but combined with above mentioned difficulty to diagnose it can lead to painful situations.

• Maven's defect backlog is quite impressive and I'm not sure that the situation is going to improve soon.

So, our next approach will be to use ant for building and restrict Maven to managing dependencies and generating project site and quality reports.

How to connect to an MS Access database using Ruby and ODBC

If you search for an answer to this question in Google, you will get mostly sarcastic answers and if you're lucky maybe some help.

You must first download Ruby ODBC from Christian Werner's site and copy odbc.so and odbc_utf8.so into the ...\ruby\1.8\i386-msvcrt directory where you installed Ruby. Uf you have installed InstantRails in default location, it should be under C:\InstantRails\ruby\lib\ruby\1.8\i386-mswin32

In the example below I connect to an Access file (c:\ruby.mdb) and print the contents of a table (Table1)

require 'DBI'

access_dsn_base = 'DBI:ODBC:Driver=Microsoft Access Driver (*.mdb);DBQ='
access_file = 'C:\ruby.mdb'

DBI.connect(access_dsn_base+access_file) do |dbh|
  dbh.select_all('Select * From Table1') {|row| p row}
end

Similarly, you can use DBI:ODBC to read MS Excel files.
In the example below I connect to an Excel file (c:\my_file.xls) and print the contents of a spreadsheet (Sheet1)

require 'DBI'

excel_dsn_base = 'DBI:ODBC:Driver={Microsoft Excel Driver (*.xls)};DBQ='
excel_file = 'C:\my_file.xls'

DBI.connect(excel_dsn_base+excel_file) do |dbh|
  dbh.select_all('Select * From [Sheet1$]') {|row| p row}
end

My configuration is Windows XP + MS Access 2000 + MS Excel 2002 + Ruby 1.8.6 + Ruby ODBC 0.9995

WebLogic 9.2 is not Maven 2 friendly

Using Maven 2 is more difficult when you use a platform like BEA WebLogic 9.2 because of their "split directory" convention which creates a gap with Maven's own conventions.

A first approach could be to avoid using the split directory structure, however it's not that easy because it comes with a set of specific ant tasks to pre-compile your JSPs, generate a web service from an EJB, package an ear file, ...
These tasks are not open sourced and are too high level to be easily integrated into Maven: for instance, if you want to pre-compile your JSPs, you cannot use anymore jspc because it has been deprecated in favor of appc which depends on the split directory structure.
This makes almost impossible to write an equivalent Maven plugin for a 3rd party, only BEA could do it.

Another issue with these tasks is that they are defined in weblogic.jar: a 50 MB jar which contains a lot of stuff that may collides with dependencies in your classpath, especially because BEA chose to specify a relative classpath in its jar manifest.

An alternative is to use the WebLogic ant tasks from Maven using the antrun plugin, unfortunately this plugin is poorly documented and does not offer easy options to configure a classpath to integrate weblogic.jar. Also, antrun retrieves its own version of ant from Maven's repository that may collide with the one required by WebLogic's tasks; you can find workarounds for this but then you will have to trick Maven to make it think that it has generated the artifact generated by appc.

So, unless BEA endorses Maven and provides its own plugins, it will be difficult to use Maven for a non trivial WebLogic application. My next step will be to try to use ant and Maven's antlib in order to be able to use Maven's dependency management.

P.S.: I just found Hussein Badakhchani's excellent post about maven and appc, I may try his approach as well.

Windows Environment Variables Trap

In Windows, you can easily define environment variables from the "My Computer" icon on your desktop. It's convenient but you can't define the evaluation order, so Windows does it for you but it does it wrongly (at least on Windows XP).

Define these variables:

V1=1
V2=%V1%-2
V3=%V2%-3
V4=4-%V5%
V5=5-%V6%
V6=6

Here is what you get:

V1=1
V2=1-2
V3=1-2-3
V4=4-%V5%
V5=5-6
V6=6


So, V4 was not correctly expanded.
We can also see that the evaluation is partly based on alphabetical order (V1, V2, V3) but that there were 2 passes as V5 is correct.

So, if you want to get safe set an evaluation order on your variables by setting them in your autoexec.bat file.

My First Ruby on Rails project

It's been a while since I wanted to refactor my PHP+Smarty web site and also to implement additional database driven features. The main purpose of this application is to manage table tennis tournament results.

CakePHP

Being hosted on a PHP box, my first idea was to look for Ruby on Rails clone in PHP.
I found CakePHP to be the only serious one able to run on PHP4 so the choice was easy.
I spent few hours during 3 weeks to learn the framework and start my project, there was no book to help so I relied mostly on simple tutorials and users forums.
CakePHP is a good framework with may useful features (some of them are even more advanced than Ruby on Rails equivalent ones) and a great community but documentation is sparse and worse: it suffers from PHP's poor syntax (at least from a Java developer's standpoint).
After 3 weeks, I decided to stop and switched to Ruby on Rails even if it meant switching to a new web hosting company.

Switching to Ruby on Rails

I bought the "Agile Web Development with Rails" book and read several tutorials.

Using existing database

First, I created my application using rails ipttc then I created a migration from my existing database.


ruby script/generate migration Initial
rake db:schema:dump


Then I copy/pasted from schema.rb into the up method of db/migrate/001_initial.rb

rake db:migrate

I found that my legacy schema was not following some of Rails conventions like having a numerical id for tables, I decided to keep it simple and adapt the rails conventions, maybe I'll dig further if needed.

Being a lazy typist, I looked at ways to generate my models from existing database and I found Dr Nic's Magic Model Generator which created 7 models with validation rules in a snap, Thanks Doc! By reviewing the generated models, I was able to learn quickly about validations and relations and I really discovered something unexpected: it did create some kind of indirect relations: "has many through".

Tournament has many Medals.
Player has many Medals.
Tournament has many Players through Medals.

And it does make a lot of sense, it's like saying:

Tournament has many Medalists.

After that, I started to play with scaffolding and I was a bit disappointed because it did not take into account relations between models. I searched for better scaffolding and found ActiveScaffold and Hobo. ActiveScaffold provides dynamic scaffolding using Ajax and nice presentation. Hobo is more a framework on top of Rails and provide additional nice features like a security model with users, roles and permissions. Both of them are very promising but they provide only dynamic scaffolding while I am more looking for a code generator to be able to learn and modify things for my needs. Also, I'm still too new in Rails to be able to select an additional framework, I must try to understand the standard Rails features first.

Fortunately, I was also looking at RESTful implementation in Rails and found that there was a new scaffold code generator that was deprecating the original one.
The good thing about scaffold_resource is that it lets you to generate the model, the views, the controller and the database table in migration at once.
You just have to list the name of your fields and types, for instance for Player and Country:


ruby script/generate scaffold_resource Player full_name:string first_name:string last_name:string birth_date:date country_id:integer gender:string class:integer dead:boolean eligible:boolean

ruby script/generate scaffold_resource Country code:string name:string

rake db:migrate


Conclusion

My application will be RESTful and I will create a new database schema.

Code Red Alert

A little story that happened to me as a hobbyist webmaster of www.ipttc.org

In previous months, I have seen our network bandwidth consumption increasing, 2 months ago I found that there was a lot of traffic coming from servers in Vietnam where our sport is not very developed but at this was at the end of the month I did not pay too much attention.

On June, 13^th, I noted a major traffic increase, I looked at the most downloaded pages and was surprised to find audio files (.wma) while we don't distribute music of course.

Then, I found that there were about 1500 such files in one directory which was the upload directory of forum for attachments. So, everything indicated that a hacker did exploit a vulnerability in the file upload module of the forum.
I decided to remove the files but it was not possible, so I renamed the directory and I logged a support ticket to get administrators to do the job.
I un-installed the file upload module and updated the forum software to most recent version.

I sent a mail to my committee qnnouncing that our web site would probably get unavailable because our network bandwidth for the month could be exceeded within next hours or days and that the downtime could last until end of the month.

Next morning, I got a mail from support saying that they deleted the files.

Unfortunately, our bandwidth got exceeded during the night and so our site was down.

I decided to look carefully at the web server log files and I found that all requests for music files came from one site www.muzic9.com. In fact, this site proposes "free" music, you choose an album and then click on a song, it then redirects transparently to an external site. So it means that when clicking on some songs you actually downloaded them from www.ipttc.org! I sent an email to the webmaster asking him to delete all links pointing to our site get and that he no longer accepts such links.

I did a "whois" query to find the site owner:

TUAN
TUAN TUAN (tuan.maxviet@gmail.com)
1.8633630
Fax: 1.8633630
Some where in VN
address
HCM, HCM 70000
VN

So the owner was from Vietnam, same country that consumed our bandwidth last month.
I did send same email to this address. No need to say, I never got any reply.

I put some additional protections in place and now monitor more seriously my bandwidth consumption report and web log files.

Subversion quick protocol benchmark

Subversion lets you choose the protocol used to connect from client to server, it has an impact on the authentication scheme but also on data transfer rate.

I ran a checkout on 2500 files and 50 MB with client running locally on server. As expected, "svn" was the fastest: "http" was 66% slower and "https" was 135% slower.

Also an export of same source tree is much faster than a checkout (up to 3 times faster in my tests depending on the number of files) because svn client does not need to create a local copy of each file nor metadata files (checksums, logs, ...) in .svn directories. So, it could be a little optimization for a build that does not need to commit any change.

Of course, when the client is remote, the impact of a slow network connection tends to lower these differences.