November 30, 2009

The Nov’09 Changes in My Life

Posted in Uncategorized at 6:31 PM by bsnaresh

This November, I saw some major changes in my professional life. This is the month, I served my last working day at Sun Microsystems. I had to undergo a lot of mental struggle in deciding whether or not to leave this great organization. But considering my personal commitments and career ambitions I had to take this tough decision.

I have joined a cloud computing startup, Sonoa Systems. There’s a sudden understandable change in the work environment – from a company with 30000+ people to a company with less that 100 employees. It might be a small organization, but is one with a great vision.

I’m happy that the new job would let me put in practice all that I have learned throughout the past five years of my career, specially, the SOAP and REST web services that  I got a chance to work on when at Sun.

One great coincidence is that I have joined Sonoa on the 27th of Nov, the same day on which I joined my Engineering College nine years back. I hope the coming days would be as lovely and fruitful as my college days 🙂 .

November 11, 2009

JTF: Running tests against an app deployed on a staging server

Posted in REST tagged , at 1:14 AM by bsnaresh

Few days back I saw somebody asking whether the Jersey Test Framework allows you to run your tests on an application which is deployed on a staging server. The answer was NO at that point of time. Then I realized that this is a common use case and that it would be good to add this support.

With this release of Jersey 1.1.4, the Jersey Test Framework now lets you run your tests against your application deployed on a staging server. All that you have to do is just set this property JERSEY_HOST_NAME to the IP Address or the domain name of the machine, i.e., the staging server, on which your application is pre-deployed.

Lets say you have your application deployed on a machine with IP 129.132.212.54, tests could be run using the following command on your local machine:

 mvn clean test 
-Dtest.containerFactory=com.sun.jersey.test.framework.spi.container.external.ExternalTestContainerFactory  
-DJERSEY_HOST_NAME=129.132.212.54 -DJERSEY_HTTP_PORT=<http_port>
  • The support for specifying the JERSEY_HOST_NAME is limited only to the external container types.
  • Apart from the JERSEY_HOST_NAME you would also need to set the JERSEY_HTTP_PORT to the port on which your server is listening.
  • For more information on the various container types supported by the framework, please refer the previous blog entry on the framework.

November 4, 2009

Hudson: A Continous Integration Tool

Posted in misc at 7:06 AM by bsnaresh

Continuous Integration Tools

     A continuous integration tool is an automated build system that
checks out the most current code from the source code repository,
builds it, and makes the resulting artifacts available for download. Such tools come handy when your application has multiple modules and there are multiple engineers working on them. These tools could be used to integrate these various modules, build the system and also maybe run some tests to ensure that everything is fine.

Hudson: What is it?

     Hudson is an open-source continous integration tool, which has become very popular for some time now. It provides various features like options for checking out the source code from various version controlling systems like CVS, SVN, etc., setting the version of Java to be used, the machine(s) on which to run the integrations/builds, notifying an user or a group of users about a build failure, scheduling the job execution, etc. More information can be obtained from the Hudson project site at http://hudson-ci.org/.

Master-Slave Configuration

          One interesting feature of Hudson is its provision to run a job in a master-slave configuration, i.e., there would be a Hudson master machine which would take up all the requests like defining a job, configuring it, triggering it, etc., while there will be a set of slave machines on which the executions would actually happen.

        Lets say you want to define a job which has to be run on more than one platform. You define it in the Hudson master, the interface for all your configurations, and then tie it to all the machines that you would want to run the job on. The underlying mechanism of Hudson takes care of all the communication between the Hudson master and each of the slaves which are registered with it.

        Now, we will see how to setup Hudson – the master and slave(s).

Setting up the Hudson Master

    The master could be setup on any OS, for convenience lets assume we are setting it up on Linux.

  • If you are using Ubuntu, be sure to upgrade to 8.04 to avoid
    problems with RSA keys (keys generated by keygenerator in 7.10 are
    blacklisted!)
  • Login as someone with root role (e.g. uadmin)
  • sudo useradd -d /space/hudson -m hudson – this creates user hudson with home in /space/hudson (Folder hudson does not need to exist)
  • sudo passwd hudson changes the password for user hudson
  • Login as hudson user
  • Create folder $HOME/jdks and install there jdk1.6.0
  • ssh-keygen -t rsa generate public / private RSA key, public key is used for ssh login to slaves without passwords
  • =touch /space/hudsonserver/master = – creates foo file master as a workaround for hudson issue #936– parent project occuppies executor on slave
  • Download hudson.war bits the Hudson site at http://hudson-ci.org/
  • Install webserver (e.g. tomcat) and deploy Hudson
  • If you do not want to run Hudson in Tomcat, use built-in server Winstone:
    • run java -jar hudson.war to start Hudson master on port 8080
    • NOTE: best idea is to use something like this script (we use in
      this script non-default port 18080 because this is second instance of
      Hudson on the same machine): 
               #!/bin/bash
# kill running hudson
kill `ps aux|awk '$13 == "./hudson.war" {print $2}'` 2> /dev/null
# nohup new hudson
nohup /space/jdks/jdk1.6.0_05/bin/java -jar ./hudson.war --httpPort=18080 --ajp13Port=18009 &

  • Once you have the war file deployed, you could launch the application.
  • Various settings like different JDKs, MAVEN_HOME could be made at the "Manage Hudson" page by clicking on the "Manage Hudson" link in the side pane.

Setting up the Hudson Slave

The following steps could be used to create a slave on a linux/solaris machine:

  • Create an user "hudson" with home in /space/hudson.
    • sudo useradd -d /space/hudson -m hudson
  • Set a password for this user
    • sudo passwd hudson
  • Login as user "hudson".
  • Create folders "ant" and "jdks" in /space/hudson.
  • Download and unzip ant into folder "ant".
  • Download and unzip various versions of jdk into jdks.
  • Copy the id_rsa.pub of the Hudson master to file
    /space/hudson/.ssh/authorized_keys. This enables the Hudson master to
    establish a remote connection to the slave without having to enter the
    login credentials. To do this:

    • Setup a FTP connection to the Hudson master.
    • Get the id_rsa.pub file from the hidden folder ".ssh".
    • Close the FTP connection.
    • Copy this id_rsa.pub file to /space/hudson/.ssh/authorized_keys. Create the directory .ssh if it doesn’t exist already.
    • To verify that the Hudson master’s key is successfully added to
      this slave’s "ssh" keys, try setting up a ssh connection from the
      Hudson master to this slave node, as "ssh hudson@your_hudson_slave".
      This should setup a connection without prompting for a password.
  • Copy the slave agent "slave.jar" to /space/hudson. The jar file
    can be obtained from the archive "hudson.war" which has been downloaded
    to setup the Hudson master. The hudson.war file may be downloaded from
    the site http://hudson.dev.java.net.
  • Write a small shell script which sets the various paths and starts
    the slave agent. Name it runSlave.sh. A typical script file would be
    like:

    • cat /space/hudson/runSlave.sh
    • echo "Starting the slave agent on the node XYZ…"
    • export JAVA_HOME=/space/hudson/jdks/jdk1.6.0_06
    • export ANT_HOME=/space/hudson/ant/apache-ant-1.7.1
    • export PATH=$JAVA_HOME/bin:$ANT_HOME/bin:$PATH
    • java -jar slave.jar
    • echo "Slave agent started…"
      • This shell script would be called by the Hudson master. Running
        the script directly would not start the slave agent, this gets started
        only when run from the Hudson master.
  • Register this slave machine with the Hudson master in the "Manage Hudson" page.

You have your Hudson Master/Slave configuration ready. Now, you could just go ahead and define, configure and schedule your jobs to run according to your choice.

 In case you have any queries you could consider sending a mail to the Hudson user’s mailing list – users@hudson.dev.java.net  which is a pretty active mailing list.