Problem with Warbler

While I was building the war/ear file I was facing problem at the building time as well as after deployment. Here I tried to mention all those problems:

1) Warbler doesn't copy .specifications file: When we execute gems:unpack:dependencies it creates .specifications file for each gem in your vendor/gems folder. Then when we execute 'war' task it doesn't copy this file into the war file. I solved this problem by adding following line in the config/warble.rb file

config.includes = FileList["vendor/gems/*/.specification"]

2) I was getting Don't know how to build task '' when log folder was there: This is something wired I got when I added the gem 'composite_primary_keys'. There are two solutions for this

• rename the log folder to some other name and then execute the war task
• in your warble.rb file use config.gems = []

3) After deployment I was getting undefined method `new' for "Rack::Lock":String: After googling I came to following solution

• download jruby-complete-1.3.1.jar from here in lib folder
• download jruby-rack-0.9.5-20090625.190033-5.jar from here in lib folder
• in config/warble.rb file add following lines
  config.java_libs.delete_if {|f| f =~ /jruby-rack/ || f =~ /jruby-complete/ }
  config.java_libs += FileList["lib/*.jar"]

4) Cannot load gem at [SYSTEM_JRUBY_CACHE_PATH] in MY_APP_FOLDER: I was getting this error when I started using 'composite_primary_keys' gem and trying to execute the war task by jruby rake. The version of this jruby rake is 0.8.7. After some analysis and testing with different version of rake I have identified that if I use older rake (version less then 0.8.4) then the problem is gone. Other thing that you can do is in your warble.rb file use config.gems = []

Some helpful links:

http://kenai.com/jira/browse/JRUBY_RACK-18

http://stufftohelpyouout.blogspot.com/2009/06/how-to-get-warbler-to-include-custom.html

http://stufftohelpyouout.blogspot.com/2009/07/fix-ioerrorio-errorbroken-pipestrange.html

http://wiki.oracle.com/thread/3104945/Error+during+jruby-rack+initialization

JRuby on Rails building with warbler

Here I will mention the steps to create a JRuby (v1.3.1) on Rails (v2.3.3) application and build the war file using Warbler (v0.9.13) gem and then deploy in the JBoss (4.2.3.GA).

See my previous blog Oracle with JRuby using activerecord-jdbc-adapter to install JRuby, Rails and activerecord-jdbc-adapter to

In real life we need to work with gems & plugins for that reason I will now install some gems and plugins. jruby-openssl is required because if you don't install it then you will get JRuby limited openssl loaded. gem install jruby-openssl for full support

- JRUBY_HOME\bin\jruby -S gem install jruby-openssl

- JRUBY_HOME\bin\jruby -S gem install mislav-will_paginate

- install wee_date_picker plugin. To see the installation instruction see http://github.com/pyrat/wee_date_picker

Now create a rails project and in the environment.rb file add followings:

#config all the gems used with this project

config.gem "activerecord-jdbc-adapter", :version => '0.8', :lib => 'jdbc_adapter'

config.gem "jruby-openssl", :version => "0.5.1", :lib => 'openssl'

config.gem 'mislav-will_paginate', :version => '~> 2.3.11', :lib => 'will_paginate', :source => 'http://gems.github.com'

I like to configure my rails app to use gems and rails that are in the vendor folder. To make all the used gems copied to vendor/gems folder execute following rake task:

RAILS_APP_HOME>JRUBY_HOME\bin\rake gems:unpack:dependencies

To freeze rails with my application execute following rake task:

RAILS_APP_HOME>JRUBY_HOME\bin\rake rails:freeze:gems

Now its time to think about building the war/ear file to deploy in JBoss. As I have already said to build the war file I use Warbler. To do that install the gem:

JRUBY_HOME\bin\jruby -S gem install warbler

Its convenient to have warbler as plugins in your application and to make the plugin use following command and then you will have the warbler plugin in your vendor/plugins folder:

JRUBY_HOME\bin\warble pluginize

To customize files, libraries, and gems included in the.war file, you'll need a config/warble.rb file. As you have already created the warble plugin you can execute following to create warble.rb file for you:

RAILS_APP_HOME>JRUBY_HOME\bin\jruby script/generate warble

Now its time to create the war file of your project. To do that execute following rake task:

RAILS_APP_HOME>JRUBY_HOME\bin\rake war

At this point everything should be done but in my case I faced couple of problems. If you face problem please see my next blog 'Problem with Warbler'

Configure Log4j with JRuby on Rails for JBoss

Its very easy to use any Java library from you JRuby code. In one of my JRuby on Rails project I had to use two different logger for logging purpose. One is the Rails default logger for all jruby code and other is log4j logger that is for my java codes and libraries. To use both of the logger I made following changes.

At first I added mylog4j.properties and log4j-1.2.15.jar in my project's lib folder. By default the ruby log file goes to log folder. If we want to keep this log file in this default folder then we don't need to change anything. A sample mylog4j.properties file content is given here:

log4j.rootLogger=DEBUG, R

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

# Pattern to output the caller's file name and line number.

log4j.appender.stdout.layout.ConversionPattern=[%d{ISO8601}] %-5p (%F:%L) - %m%n

log4j.appender.R=org.apache.log4j.RollingFileAppender

log4j.appender.R.File=/opt/jboss/server/default/log/myapp_rails.log

log4j.appender.R.MaxFileSize=10000KB

# Keep one backup file

log4j.appender.R.MaxBackupIndex=5

log4j.appender.R.layout=org.apache.log4j.PatternLayout

log4j.appender.R.layout.ConversionPattern=[%d{ISO8601}] %-5p (%F:%L) - %m%n

log4j.logger.org.apache.commons.digester=WARN

log4j.logger.org.apache.commons.beanutils=WARN

log4j.logger.org.apache.commons.validator=WARN

log4j.logger.org.apache.commons.httpclient=DEBUG

log4j.logger.org.springframework=DEBUG

In my case I developed a JRuby on Rails application that was deployed in JBoss server. Thats why I decided not to use the default log folder of Rails application for log files rather use the JBoss log folder to store the log files.

For that reason I need to know the log folder path of JBoss in my environment.rb file and then change the log file path that will be used by Rails. You can get the JBoss log folder path by:

java.lang.System.getProperty('jboss.server.log.dir')

So the corresponding changes in environment.rb file that I made are:

jboss_server_log_dir = java.lang.System.getProperty('jboss.server.log.dir')

if jboss_server_log_dir

config.log_path = File.join(jboss_server_log_dir,'frengine_admin.log') if (jboss_server_log_dir && !jboss_server_log_dir.strip.empty?)

end

config.logger = Logger.new(config.log_path, 50, 1048576)

And to specify the same log folder in the mylog4j.properties file I used following line:

log4j.appender.R.File=${jboss.server.log.dir}/myapp_java.log

Now you will be able to see two different log file in the JBoss log folder. If you want to use same log file for all kind of logging use single file name.

JRuby on Rails: using JDBC driver

In JRuby world the bridge between Rails activerecord and JDBC driver is activerecord-jdbc-adapter. activerecord-jdbc-adapter allows you to use virtually any JDBC-compliant database with your JRuby on Rails application. You can verify the supported JDBC-compliant database by going to JRUBY_HOME\lib\ruby\gems\1.8\gems\activerecord-jdbc-adapter-0.8\lib\active_record\connection_adapters. For every supported database you will have databasename_adapter.rb file. Please see my blog 'Oracle with JRuby using activerecord-jdbc-adapter' to install JRuby, Rails and activerecord-jdbc-adapter and test your installation is correct.

Now its time to configure the database.yml file. Since version 2.0 Rails automatically look for and load an adapter gem based on the name of the adapter you specify in database.yml. Example:

development:

adapter: jdbc

...

With this database configuration, Rails will attempt to load the activerecord-jdbc-adapter gem. Here is an example for oracle database:

development:

adapter: oracle

driver: oracle.jdbc.driver.OracleDriver

url: jdbc:oracle:thin:@localhost:1521:XE

username: username

password: password

If you want to work with the connection itself then require the active_record/connection_adapters/jdbc_adapter library and call the method ActiveRecord::Base.jdbc_connection in order to obtain a connection to the database:

require 'rubygems'
require 'active_record'
require 'active_record/connection_adapters/oracle_adapter'

ActiveRecord::Base.jdbc_connection

In upcoming blog I am going to write on using JNDI in your JRuby on Rails application and deploying in JBoss.

Oracle with JRuby using activerecord-jdbc-adapter

• Download jruby from http://dist.codehaus.org/jruby/1.3.1/ and install it. For convenience you can set an environment variable JRUBY_HOME = C:\jruby-bin-1.3.1\ (/opt/jruby-1.3.1 for linux/OSX) and optionally you can add this environment variable to the PATH variable.
  
  set PATH=%PATH%;JRUBY_HOME (windows)
  export PATH=$PATH:JRUBY_HOME (linux or OSX)
  
  
• install rails using jruby -S gem install -y rails (in my time the latest one was 2.3.3)
  If you didn't set the environment varilable in the path variable then you will have to execute following command:
  JRUBY_HOME\jruby -S gem install -y rails
  If you want to specify version then
  jruby -S gem install -y rails --version 2.3.3
• install activerecord-jdbc-adapter (version - 0.8) using
  jruby -S gem install -y activerecord-jdbc-adapter --version 0.8 or
  JRUBY_HOME\jruby -S gem install -y activerecord-jdbc-adapter --version 0.8
  
  At first I installed the newer version 0.9.1 but with that version I was getting following error for timestamp type column: "undefined method 'new_date' for JdbcSpec::Oracle::Column:Module". I have a plan to solve this problem later
• Now its time to test activerecord, activerecord-jdbc-adapter, jdbc-driver from jirb. To test we need couple of tables in the database. Lets say we have two tables:
  - authors
  - articles [an author can have multiple articles]
• Now copy the oracle-jdbc-driver jar file (ojdbc14-10.2.0.1.0.jar) in the JRUBY_HOME\lib folder then run 'jirb'. To run "jirb" in command prompt go to JRUBY_HOME\bin and type 'jirb'. Now in the 'irb' console type followings:
  
  require 'rubygems'
  require 'active_record'
  require 'active_record/connection_adapters/oracle_adapter'
  
  class Author < adapter =""> 'jdbc',
  :driver => 'oracle.jdbc.driver.OracleDriver',
  :url => 'jdbc:oracle:thin:@localhost:1521:XE',
  :username => 'username',
  :password => 'password')
  
  Author.all()

Here you go !! You are done !!

Some useful links:

• http://jruby-extras.rubyforge.org/activerecord-jdbc-adapter/
• http://api.rubyonrails.org/classes/ActiveRecord/Base.html

Extending Capistrano (1.x) task

You can extend the default behavior of Capistrano by different ways. Here I am mentioning the ways that I used to extend the default Capistrano behavior.

Writing Custom Task

We used Capistrano for the first time in a project [www.scrumpad.com] to deploy our application. We used Rails 1.2.5 and the default support from Capistrano was fine for us. But in next project when we were trying to use Capistrano to deploy our Rails application we felt the necessity of extending the default behavior of Capistrano.

In the second case we had different servers (6 servers) to deploy the application in development (2 servers), testing (2 servers) and production (2 servers) environment. We were planning to use the same capfile for deployment in all the servers. There were different configurations for different types of environments and we needed something that will do the configuration based on the user command.

Capistrano has nice support to extend its default behavior to write custom tasks. For our purpose we made three tasks (development, testing, production) and each task set the environment of each environment.

desc "this task sets the development environment"

task :development do

role :app, "my.dev1.server.ip"

role :app, "my.dev2.server.ip"

set :environment, "development"

end

Now as we want to set the environment before any standard Capistrano task start running we run the capfile in this way:

cap [environment] [standard_capistrano_task]
i.e. cap development setup

Using the Event Framework

In Capistrano 1.x we can extend a default task my creating new tasks whose names are prefixed with 'before_' and 'after_'. For example depending on the environment we need to change the value of 'deploy_to' in our application. In that case we can write another task 'before_deploy':

desc "this task set the value for deploy_to based on the value of 'environment'"

task :before_deploy do

if environment == 'development'

set :deploy_to = "deploy_folder_path_in_development_server"

elsif environment == 'testing'

set :deploy_to = "deploy_folder_path_in_testing_server"

elsif environment == 'production'

set :deploy_to = "deploy_folder_path_in_production_server"

end

end

So this task will be called before the calling of 'deploy' task. Similarly if you want to do some extra work after 'deploy' task is called in that case you could write a new task 'after_deploy'

Overriding default task

As I have already said, I was using Capistrano for Rails application. Later for a Ruby application I need to use Capistrano to deploy the application in server and here I found a problem. In Rails application there is a folder 'Public' and the default 'update_code' task makes a link to that folder. But as I was trying with Ruby application where there is no 'Public' folder I was getting an error. To solve the problem I override the standard implementation by creating the same task with custom implementation. Here is the code:

desc <<-DESC
Update all servers with the latest release of the source code. All this does is do a checkout (as defined by the selected scm module). This task is modified for Ruby application
DESC

task :update_code, :except => { :no_release => true } do

on_rollback { delete release_path, :recursive => true }

source.checkout(self)

set_permissions

run <<-CMD rm -rf #{release_path}/log #{release_path}/public/system &&

ln -nfs #{shared_path}/log #{release_path}/log

CMD

@releases = nil

end

In future I will post more on how to extend the default Capistrano tasks with other ways.

Connecting with Oracle from you ruby/rails applications on an "Intel Mac OS X" using DBI with OCI8

Prerequisite:

- Mac OS X (10.5.5)
- ruby --version => 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]

NOTE: Here the machine where i am working is 'SBKislamzD1' and the user name is 'islamz'. In your case just replace this user name with your user name

Installing DBI

The easiest way of installing a gem is using gem command [gem install dbi] But here I am going to use OCI8-1.0.3. With this version of OCI8 library not all the version of DBI works. In my case DBI version 0.2.0 worked. You can't install this version (0.2.0) of DBI using gem install. You need to downloaded the tar file and unzip it.

Lets say the unzip folder is /Users/islamz/Downloads/dbi-0.2.2
Now open a terminal/console and goto /Users/islamz/Downloads/dbi-0.2.2 and run following commands:

> ruby setup.rb config --with=dbi
> ruby setup.rb setup

Now you should run the following command with 'sudo'

> sudo ruby setup.rb install

If you have any other version of DBI gem you might need to uninstall that gem

Installing Oracle Instant Client

At first from http://www.oracle.com/technology/software/tech/oci/instantclient/htdocs/intel_macsoft.html download following packages:

• - Instant Client Package - Basic (10.2.0.4)
• - Instant Client Package - SQL*Plus (10.2.0.4)
• - Instant Client Package - SDK (10.2.0.4)

Now unzip all of packages in /Library/Oracle/instantclient_10_2. After unzipping you should have followings in this folder:

• - BASIC_README
• - classes12.jar
• - genezi
• - glogin.sql
• - libclntsh.dylib.10.1
• - libnnz10.dylib
• - libocci.dylib.10.1
• - libociei.dylib
• - libocijdbc10.dylib
• - libocijdbc10.jnilib
• - libsqlplus.dylib
• - libsqlplusic.dylib
• - ojdbc14.jar
• - sdk
• - sqlplus
• - SQLPLUS_README

Its now time to add some environment variables. For this purpose open /etc/profile in edit mode and add the environment variables as stated below:

• Open the file in edit mode using: sudo vi /etc/profile
• Add following in this file:
  
  ORACLE_HOME=/Library/Oracle/instantclient_10_2
  export TNS_ADMIN=$ORACLE_HOME
  export LD_LIBRARY_PATH=$ORACLE_HOME
  export DYLD_LIBRARY_PATH=$ORACLE_HOME
  export PATH=$PATH:$ORACLE_HOME
  
  
• Save the file and logoff then login
• To test whether the environment variables are set or not type 'env' in terminal(console)

Now you need to create symlinks. To do this follow these steps:

• open a terminal/console and goto /Library/Oracle/instantclient_10_2
• sudo ln -s libclntsh.dylib.10.1 libclntsh.dylib
• sudo ln -s libocci.dylib.10.1 libocci.dylib
• in /Library/Oracle/instantclient_10_2 folder you will find two new symlink

Compiling ruby-oci8

To compile ruby-oci8 follow the steps as stated below:

• download the ruby-oci8-1.0.3.tar If you are using Safari then it will be downloaded in /Users/islamz/Downloads/
• unzip it to ruby-oci8-1.0.3 (/Users/islamz/Downloads/ruby-oci8-1.0.3)
• run terminal/console and goto /Users/islamz/Downloads/ruby-oci8-1.0.3
• export SQLPATH=$ORACLE_HOME
• export RC_ARCHS=i386
• ruby setup.rb config
• make
• sudo make install [Don't forget to run this command as 'sudo']
  

So, you are done. Now you need to test whether your compilation is okay or not.

You can easily test by following these steps:

• run terminal/console
• irb
• require 'oci8' #it should return 'true'

If there is no error then you installation is SUCCESSFUL


SIDE NOTES

1) How to check which version of DBI is supported:

- goto /Library/Ruby/Site/1.8/DBD/OCI8/
- open the file OCI8.rb
- check the value of USED_DBD_VERSION. [In my case it was "0.2"]

2) Problems with NetBeans:

If you are using NetBeans for developing your project in that case you might face some problems:

a) You might get some permission related problems. So run Netbeans with sudo

b) When running your application if it throws an error that 'libclntsh.dylib.10.1' is not found in '/scratch/plebld/208/rdbms/lib/' then put the file in the specified path

c) When running your application you are getting this error:

OCIError (Error while trying to retrieve text for error ORA-24812):
lob.c:194:in oci8lib.so
/Library/Ruby/Site/1.8/oci8.rb:1005:in `write'

It means when you are running NetBeans as sudo the environment variables are missing. Follow these steps:

• SBKislamzD1:~ islamz# sudo su
• sh-3.2# ORACLE_HOME=/Library/Oracle/instantclient_10_2
• sh-3.2# export ORACLE_HOME=$ORACLE_HOME
• sh-3.2# export TNS_ADMIN=$ORACLE_HOME
• sh-3.2# export LD_LIBRARY_PATH=$ORACLE_HOME
• sh-3.2# export DYLD_LIBRARY_PATH=$ORACLE_HOME
• sh-3.2# export NLS_LANG=AMERICAN_AMERICA.AL32UTF8
• sh-3.2# /Applications/NetBeans/NetBeans\ 6.1.app/Contents/MacOS/netbeans