perlmod_bldr
============

The Perl Module Builder package uses the improved CPANPLUS mechanism of CPAN
to harvest the CPAN modules needed and store them in a local CPAN repo.
This local repo and some scripts are tar'd with the autoconf "make dist" 
mechanism.  This defines a versioned release of a group of CPAN perl modules.

The release is now a package just like any other autotools package that can be
unpacked, configured with "./configure" and installed.

This pacakge was long in coming and took alot of "experimentation"...

CPAN doesn't really like the concept of what the Free Software Foundation calls
a "Staged Install".  The scripts in this package have to bend over backwards to 
get CPANPLUS to setup perl to deal with the DESTDIR scratch directory as a 
installation target prior to packaging.  Also got the tests to run in the staged
install directory so you are resonably sure your are getting the software
functioning like the developer upstream intended.



This package is currently very early...
It doesn't yet deal with firewall proxies.
   This is a bootstrap problem as you need several perlmods to interact
   with a proxy and you need to force LWP as a transport.
It doesn't yet deal with itself being installed!!!
   This may get tricky to fix...
Doesn't yet modularize CPAN modules into package groups
Is a first attempt from a non-perl coder (Lee Thompson)

That said, it is potentially a cure for numerous problems.

1) Give you versioned releases of bundles of perl modules and, since it is
   versioned, gives you an easy backout if the upgrades introduce side 
   effects.
2) Very easy to get current with the latest upgrades introduced on CPAN
   by updating the version in "configure.ac" and running "configure_pkg.sh"
3) This technique defends against a scary phenomena where perl modules
   dissapear off of CPAN.  We have had apps running against old versions
   of perl modules which could not be upgraded for various reasons to 
   the latest version of the depedent perl modules.  When you use this 
   package, you have all the source code of your upstream dependencies.
4) Adding to this bundle, while not as straightforward as rubygems_bldr,
   is somewhat straightforward for most perl modules on cpan.
5) Supports what the free software foundation calls a "staged install"
   http://www.gnu.org/software/automake/manual/html_node/DESTDIR.html#DESTDIR
   Staged install is a mandatory feature for package managers like
   RPM, gentoo, debian...

Errata...

1) You have to hit carraige return a few times during the CPANPLUS fetches.
   A decent perl programmer should be able to figure this out.  Somewhat
   aleviated by autconf script redirecting STDIN when calling the 
   get_cpan_modules.pl script...
2) RPM2 should be left out until CPANPLUS can deal with patches.  RPM2 only
   runs on linux at current time even though RPM is portable to Mac, Solaris,
   Cygwin, etc
3) As mentioned, this doesn't work yet underneath the firewall, this should be
   addressed as soon as possible somehow.  Has a bootstrap issue as you have
   to get several perl modules before you can get SOCKS5 support
4) The package knows that it can't run if it is already installed and does
   some basic checks and bails out if an installation is detected.

Five anti-patterns were seen in upstream CPAN modules

1) Unspecified dependencies; DBIx::Recordset for instance
2) Fails to complete tests properly
3) Module needs user input like "Yes", "No" or simple carraige return
4) Circular dependencies (DateTime and DateTime::TimeZone for example)
5) Even though a module has Build.PL implemented, it won't work unless
   the older "makemaker" Makefile.PL build script is used.

An idea I had was to implement a Perl object CPANPLUS::Stager which
would take a hash of perlmodule names and flags specifying 

    o  build phase (deals with missing or circular deps)
    o  skiptest
    o  STDIN input
    o  makemaker use
    o  Proxy server, username, password

Another idea is to investigate the CPANPLUS distribution support, see
"cpan2dist", "CPANPLUS::Dist::Deb", "CPANPLUS::Dist::Build", and 
"CPANPLUS::Dist::Sample"



                        Lee Thompson
                        20-Feb-2008