Architecting Solutions

Yesterday was my one year anniversary with Red Hat specifically with the JBoss the middleware division.  I am a Middleware Solutions Architect or "SA."

I haven't blogged much since joining Red Hat.  The drop in output is partially due to time constraints.  In the past year I have been in
Atlanta, Boston, Canton, GA, Franklin, TN, Ft. Lauderdale, Knoxville, Memphis, Miami, Mt. View, Nashville, Orlando, Pittsburgh, Raleigh, San Francisco, Tampa, and Washington D.C. 

Another reason for the reduced output is that I had not written my disclaimer post either.  This is the disclaimer post.

I have largely avoided opinionated posts focusing instead on solutions to real problems.  However, I don't get my hands dirty in code on a daily basis any more.  I still plan to focus on real solutions, but I might add some opinion, observations and predictions.  So be forewarned, the opinions that you read here belong to a Red Hat employee.

Red Hat is a great place to work, btw.

Rubykoans.com

A few years ago I decided to follow the Pragmatic Programmer's suggestion to learn a new language each year.

I started with Groovy. I make my living coding Java. I figured that I would get the most bang for my buck with Groovy. Groovy's XML utilities alone have saved me tons of time. I've also done a project in Grails, and I would gladly do another one.

I picked up Python next. I like Python, and I have had some fun monkeying with Google AppEngine. I have not had the chance to use it professionally.

I had intended to pick up Ruby last year. Several of the best people I've worked with, one of whom is a best selling Java author, have extolled Ruby's virtues to me. Hectic schedules and a job change threw a wrench into my plans so I'm picking up Ruby this year.

I have been enjoying rubykoans for the past couple of days. The koans consist of a handful of ruby files full of assertions that don't pass. By correcting and filling them in the files of course begin to work.

Simply running "rake" in the directory tells you how many you have completed. You are even rewarded with ASCII art upon completing a koan.

KVM : disabled by BIOS

I had no idea what Intel AMT was before I tried to fire up libvirt.

While working through the Fedora virtualization quick start, I ran :

$ lsmod | grep kvm

which should have returned :

$ lsmod | grep kvm
kvm
kvm_intel

Unfortunately I had only, "kvm." The troubleshooting guide suggested running :

$ dmesg | grep -i kvm

Which returned,

$ dmesg | grep -i kvm
KVM: disabled by BIOS

Happy day. I booted into the BIOS ("Press the blue, ThinkVantage button!") and disabled AMT. Unfortunately that didn't do it either. I rebooted again, pressed "the blue, ThinkVantage button," chose "CPU" and enabled the two settings for virtualization,"Intel Virtualization Technology" and "Intel VT-d Feature."

After the next reboot all was well.

SOAPui

This post is a shameless plug for soapUI.

I came across soapUI while running through the Self-Paced Workshop for the JBoss SOA Platform (pdf download.) It is incredibly simple to create a test for a web service. There is even an Eclipse plugin, but I haven't tried that yet.

Happy coding.

Recursive setfacl or how to add your PostgreSQL data directory to Git

This was an interesting annoyance.

I was working on some examples and wanted to be able to delete everything cleanly after I was done.

I had an instance of JBoss and wanted PostgreSQL to use a local directory for data.

My directory structure was :
example/
data
jboss-eap-5.1
logs

I had a user "postgres" to run PostgreSQL. Since the rest of the directory was created by me, "jeremy," I used setfacl to add "postgres" to the data directory:

setfacl -m u:postgres:rwx ./data/

When I ran :

initdb -D data/

It wasn't happy. I got :

"initdb: could not change permissions of directory"

Next up was :

sudo chown -R postgres:postgres data/

That worked for "initdb." I was able to su to the "postgres" user and execute "initdb" in "data/."

I was happy until I tried to add "data/" to Git :

[jeremy@jeremy example]$ git add data
error: open("data/PG_VERSION"): Permission denied
error: unable to index file data/PG_VERSION
fatal: adding files failed

setfacl to the rescue!

sudo setfacl -Rm u:jeremy:rwx ./data/

Unfortunately I got the same error.
I was missing the important "d" argument. The following worked :

sudo setfacl -Rm u:jeremy:rwx,d:u:jeremy:rwx ./data/

"sudo" was necessary because of changing the ownership to the "postgres" user.

I added everything to Git.

The moral of this rambling story : use the "d" flag with setfacl to cascade permissions to the files.

xlcip or How to copy past from the command line to x-windows

Brain Ashburn, my colleague in the Atlanta Red Hat office, introduced me to the xclip utility today. It copies output from the command line and puts it into x-windows.

For example, to copy the current directory :

 pwd | xclip -i -sel "clip"

There are of course more useful things that can be piped to it. To try it out create a file, add some text and :

cat newfile | xclip -i -sel "clip"

Its available through yum :

sudo yum install xclip

Installing MySQL with Yum

A quick note on installing mysql with yum in case anyone else is lazy (like me) and runs :

sudo yum install mysql

That only installs half of what's needed. nixCraft sums it up nicely for RHEL. It also works for Fedora :

$ sudo yum install mysql
$ sudo yum install mysql-server

To start it up and set the root user/password :

$ sudo yum install mysql
$ sudo chkconfig mysqld on
$ sudo /etc/init.d/mysqld start
$ mysqladmin -u root password PASSWORD
$ mysql -u root -p