Saturday, 4 July 2015

How to become a Strehler developer

Strehler is a strange package to develope. It's easy to install from repository and use, but while you are just writing it you have to arrange many tricks to be confortable with the work. For example, Strehler needs a Dancer2 site to run, something the respository doesn't contain.

In this little tutorial I'll try to explain how to setup an environment to become a Strehler developer, because Strehler needs you, as any of the packages published on CPAN. It's a very basic tutorial, useful for beginners too.

I hope it will help.

The repository

You probably already have a sandbox created in one of the many ways available for perl development. I'm still a fan of the good'ol local::lib but it's good to use also, for example, perlbrew. Your sandbox has to be active during Strehler development and you have to put in it Dancer2
cpanm --notest Dancer2
But NOT Strehler. After installing Dancer2 most of the library useful to work with Strehler will be in place, but probably you'll need something more, libraries specific to Strehler work. Just install them in your sandbox the same way using cpanm when running the code point out their absence..

You'll surely need:

All this packages are in the requirements of Strehler package and would come automatically installing Strehler for CPAN. Installing them manually is the cleanest way to obtain them, but you can try some trick, like installing Strehler and then deleting it from repository, keeping all its dependencies.

The code

Just pull down all the source from the git repository in a directory you like
git pull 
Downloading the repository you'll have a directory named $GITURL/src/lib and one named $GITURL/src/script. These two directories will come useful soon.

The environment

Now that you have Strehler code it's easy to modify it and manage changes using git. Less obvious how to use this code and see it working. We just need to customize a little the environment. Open a file named strehler-devel and put in it
alias perl="perl -I$GITURL/src/lib"
alias strehler="perl -I$GITURL/src/lib $GITURL/src/script/strehler"
When the file is ok source it.
source strehler-devel

Testing site

All Strehler power is now available, coming directly from the git repository on your machine. Now you can easly create a testing site with Strehler onboard using strehler script itself.
strehler demo 
Just run it as
perl bin/ 
to see Strehler and (eventually) your modifications in action.