Re: Extending AutoRequires for mod_perl, etc.

[Richard Siddall <cobalt elirion net>]

Richard Siddall wrote:
> I'm packaging up a Perl application that uses mod_perl and HTML::Mason 
> and was wondering if anyone could point me at some information on 
> extending rpm's AutoRequires as I'd like to automatically pull Perl 
> dependencies from at least the HTML::Mason handler file.  RPM's standard 
> AutoRequires ignores that file as it has a .pl extension.

This is what I wound up doing as a first pass (sorry about the line
wrapping):

%prep
# Override find-requires/find-provides to supplement Perl requires for
# HTML::Mason file handler.pl
cat << \EOF > %{name}-req
#!/bin/sh
tee %{_tmppath}/filelist | %{_rpmlibdir}/rpmdeps --requires | sort -u
grep handler.pl %{_tmppath}/filelist \
| xargs %{_rpmlibdir}/perldeps.pl --requires \
| grep -v -E '^perl\((lib|strict|vars)\)$' \
| sort -u
EOF

%define __find_provides %{_rpmlibdir}/rpmdeps --provides
%define __find_requires %{_builddir}/%{name}-%{version}/%{name}-req
%{__chmod} +x %{__find_requires}
%define _use_internal_dependency_generator 0

To summarize:
- You have to define _use_internal_dependency_generator to 0 to turn off
the internal dependency generator.  I couldn't find any information on
expanding the internal dependency generator.
- I found a heated discussion between Jeff and people on the RH dev list
in which he pointed out that you shouldn't use this method for filtering
dependencies.
- From that discussion I learned that rpmdeps gives similar results to
the internal dependency generator, so I used that instead of the old
find_provides and find_requires.
- The replacement requires script saves the list of files being
processed into a temporary file, then searches it for the HTML::Mason
handler file (by file name, yuck) and runs that through a dependency
checker.
- I'm assuming that there are no significant Provides to be found in the
HTML::Mason handler file.

While this works well enough for now, I may go back and revisit it.  The
elegant way to do it is to find the Apache conf files and parse out the
PerlModule, PerlRequires, and PerlHandler lines (possibly using
Apache::ConfFile?).  The conf files may not be in /etc/httpd/conf.d as
the RPM might symlink to them.  Files referenced in PerlRequires lines
need to be run through a Perl dependency checker.  PerlHandler lines
tell you which module-specific parser has to be run on the files
referenced in the enclosing Directory and/or Files directive.
PerlModule lines are simple dependencies.  (The presence of any mod_perl
directives in the Apache conf files indicates that mod_perl is required,
but that gets to be a chicken and egg situation: if you didn't know
mod_perl was required, why would you run the conf file through a
mod_perl dependency checker?)

I hope this helps should anyone have to expand dependency checking in
the future.

Regards,

	Richard Siddall