OpusVL is an open source development company based in the UK that has been in business since 2000. They provide bespoke software solutions for businesses using Perl and related technologies like Moose and Catalyst. One example project is a large intranet application for a national car dealership with multiple domains. The presentation discusses their modular architecture and use of Catalyst plugins as well as their deployment and packaging practices.

1. Perl in the Real World
Jon Allen (JJ) – jj@opusvl.com
YAPC::Europe 2010
Perl in the Real World
Open Source Business Systems
www.opusvl.com

2. About OpusVL
• Open Source development company
• Based in Rugby, UK
• Founded in 2000
– Celebrated our 10th anniversary in January 2010
• Provide Open Source business systems
– National retailers, financial institutions, SMEs
– Solutions, not code
Perl in the Real World
Open Source Business Systems
www.opusvl.com

3. What do we do?
• Bespoke software development
– Back-office / financial systems
– eCommerce
– Intranet applications
• Proud to use Perl
– And Moose, Catalyst,
DBIx::Class, cpanminus,
Test::More, etc
http://xkcd.com/208/
Perl in the Real World
Open Source Business Systems
www.opusvl.com

4. Intranet project
• National chain of car dealerships (UK)
• Very large feature set
• Multiple domains
– Sales, HR, Customer Service, Finance
• Future plans
– Integrate all back-office systems
Perl in the Real World
Open Source Business Systems
www.opusvl.com

5. Architecture
• Two key design considerations:
• Entensible
– Long life-cycle, always adding new features
• Maintainable
– Modular design, develop and update individual
components independently of the whole system
Perl in the Real World
Open Source Business Systems
www.opusvl.com

6. Pluggable Catalyst apps
• Create a "base" application
– Common functions, views, models etc
– Authentication and access control
– Standard user interface components
• Write application plugins as CatalystX::
components
• Combine these together into a new Catalyst app
Perl in the Real World
Open Source Business Systems
www.opusvl.com

7. CatalystX::AppBuilder
• Programmable configuration for Catalyst
applications
– Define your application in code
– Extend in the next app, then extend again and so on
• Handles inheritance path for components
– e.g. a chain of template directories for
Catalyst::View::TT
– $self->inherited_path_to('root','templates')
Perl in the Real World
Open Source Business Systems
www.opusvl.com

8. CatalystX::InjectComponent
• Injects Controller, Model, and View components
into a Catalyst application
after 'setup_components' => sub {
my $class = shift;
CatalystX::InjectComponent->inject(
into => $class,
component => 'My::Other::Controller::JJ',
as => 'Controller::NewName',
);
}
• Create components with CatalystX::Starter
Perl in the Real World
Open Source Business Systems
www.opusvl.com

9. Deployment
• Base OS – typically Debian
• Three environments
– Development
– Staging
– Production
• Always compile Perl from source
– System Perl belongs to the OS, custom Perl 5.10.1
for applications
Perl in the Real World
Open Source Business Systems
www.opusvl.com

10. First rule of Installation Club
• Everything installed to Staging and Production
must be packaged as CPAN-style modules
– Standard module layout
– Makefile.PL, t/*, Pod documentation
– All modules are versioned
• Very simple to regress to a previous release
• Perl is the OS
– Unlike native OS packages, CPAN works on Debian,
RHEL, Mac OS X, Solaris, etc
Perl in the Real World
Open Source Business Systems
www.opusvl.com

11. Use the toolchain, Luke
• Install using cpanminus
– Resolves dependencies
– Very fast
– Standard install procedure for each project
– cpanm --sudo --installdeps .
• Components of a large system can be managed
and upgraded independently
Perl in the Real World
Open Source Business Systems
www.opusvl.com

12. Future
• Internal CPAN mirror
– Include all custom code
– Task:: modules to set up client environments
• Internal Perldoc
– Develop on top of Perldoc::Server
• Don't fight it, feel it
– CPAN toolchain gives many benefits
– Well worth using!
Perl in the Real World
Open Source Business Systems
www.opusvl.com

13. Conclusion
• Clients care about results, not code
– The technology is our job
• Perl gives us the tools to deliver
• The Perl Community makes it possible
• Thank you!
Perl in the Real World
Open Source Business Systems
www.opusvl.com