Config::Model::Dpkg::Dependency(3pm)

NAME
Config::Model::Dpkg::Dependency - Checks Debian dependency declarations

SYNOPSIS
 use Config::Model ;
 use Log::Log4perl qw(:easy) ;
 use Data::Dumper ;

 Log::Log4perl->easy_init($WARN);

 # define configuration tree object
 my $model = Config::Model->new ;
 $model ->create_config_class (
    name => "MyClass",
    element => [
        Depends => {
            'type'       => 'leaf',
            'value_type' => 'uniline',
            class => 'Config::Model::Dpkg::Dependency',
        },
    ],
 ) ;

 my $inst = $model->instance(root_class_name => 'MyClass' );

 my $root = $inst->config_root ;

 $root->load( 'Depends="libc6 ( >= 1.0 )"') ;
 # Connecting to qa.debian.org to check libc6 versions. Please wait ...
 # Warning in 'Depends' value 'libc6 ( >= 1.0 )': unnecessary
 # versioned dependency: >= 1.0. Debian has lenny-security ->
 # 2.7-18lenny6; lenny -> 2.7-18lenny7; squeeze-security ->
 # 2.11.2-6+squeeze1; squeeze -> 2.11.2-10; wheezy -> 2.11.2-10; sid
 # -> 2.11.2-10; sid -> 2.11.2-11;

DESCRIPTION
This class is derived from Config::Model::Value. Its purpose is to check the value of a Debian package dependency for the following:

•   syntax as described in http://www.debian.org/doc/debian-policy/ch-relationships.html

•   Whether the version specified with ">" or ">=" is necessary. This module checks with Debian server whether older versions can be found in Debian old-stable or not. If no older version can be found, a warning is issued (unless the package is known or calculated to be virtual)

•   Whether a Perl library is dual life. In this case the dependency is checked according to Debian Perl policy <http://pkg-perl.alioth.debian.org/policy.html#debian_control_handling>. Because Debian auto-build systems (buildd) will use the first available alternative, the dependency should be in the form :

    •   "perl (>= 5.10.1) | libtest-simple-perl (>= 0.88)" when the required perl version is available in sid. ".

    •   "libcpan-meta-perl | perl (>= 5.13.10)" when the Perl version is not available in sid

Cache
Queries to Debian server are cached in "~/.config_model_depend_cache" for about one month.

BUGS

•   Dependencies containing variables (e.g. "${foo}") are accepted as-is. No check are performed.

•   Virtual package names are found scanning local apt cache. Hence an unknown package on your system may be a virtual package on another system.

•   More advanced checks can probably be implemented. The author is open to new ideas. He's even more open to patches (with tests).

AUTHOR
Dominique Dumont, ddumont [AT] cpan [DOT] org

SEE ALSO
Config::Model, Config::Model::Value, Memoize, Memoize::Expire