can not add plugins without making change on modules.conf files

[support.os]

Hello, 

We are installing the ocsinventory client on debian (more specifically we repackage and install ocsinventory-agent-2.8 on a debian 8 chroot).

Our problem is that we now need to provide a plugin to list the usb devices connected to the machine.
But adding a plugin on ocsinventory-agent requires modifying the configuration file "/etc/ocsinventory/modules.conf" provided by the ocsinventory-agent package.

In order to repackage the agent, we have considered 2 solutions that require modifying the " UnixAgent\lib\Ocsinventory\Agent\Hooks.pm" file :
1.	Comment out the line "last ;" in the new function when browsing the folder list $self->{config}->{etcdir}
a.	With this we can load modules.conf files from '/etc/ocsinventory' AND '/usr/local/etc/ocsinventory' AND '/etc/ocsinventory-agent' AND $ENV{HOME}.'/.ocsinventory'
b.	Not verif good but simple
2.	Add a loop that looks for a sub-folder "modules.conf.d" in the folder containing the "modules.conf" file to load additional configuration files.

In the end, we choose the second solution, so the function « new » look like this now :

sub new {
    my (undef, $context) = @_;

    my $self = {};
    $self->{accountinfo} = $context->{accountinfo};
    $self->{accountconfig} = $context->{accountconfig};
    my $logger = $self->{logger}=$context->{logger};

    $self->{config} = $context->{config};

    $self->{dontuse} = 1;

    my $modulefile;
    foreach (@{$self->{config}->{etcdir}}) {
        $modulefile = $_.'/modules.conf';
        if (-f $modulefile) {
            if (do $modulefile) {
                $logger->debug("Turns hooks on for $modulefile");

                # Check and load additionnal files from modules.conf.d directory
                if (-d $_.'/modules.conf.d') {
                    my $pluginsdir = $_.'/modules.conf.d';
                    my $dh;
                    if ( opendir($dh, $pluginsdir) ){
                        my @dots = readdir($dh);
                        foreach (@dots) {
                            next unless (-f $pluginsdir."/".$_);
                            next unless ($pluginsdir."/".$_ =~ m/\.conf$/);
                            if ( -f $pluginsdir."/".$_ ){
                                my $modulepluginfile = $pluginsdir."/".$_;
                                if (do $modulepluginfile) {
                                    $logger->debug("Turns hooks plugins on for $modulepluginfile");
                                    $self->{dontuse} = 0;
                                } else {
                                    $logger->debug("Failed to load `$modulepluginfile': $?");
                                }
                            }
                        }
                    }
                    closedir $dh;
                }

                $self->{dontuse} = 0;
                last;
            } else {
                $logger->debug("Failed to load `$modulefile': $?");
            }
        }
    }

    if ($self->{dontuse}) {
        $logger->debug("No modules will be used.");
    } else {
        my $ocsAgentServerUri;

        # to avoid a warning if $self->{config}->{server} is not defined
        if ($self->{config}->{server}) {
            $ocsAgentServerUri = "http://".$self->{config}->{server}.$self->{config}->{remotedir};
        }

        if ($self->{config}->{debug}) {
            $::debug = 2;
        }
    }

    # Create objects for modules 
    foreach my $package (searchModules(\%Ocsinventory::Agent::Modules::)){
        my $module = new $package($context);
        my $name = $module->{structure}->{name};
     
        # Store the reference in a key to access modules easily  
        $self->{modules}->{$name}=$module;

    }

    bless $self;
}

In few month we will move to Debian 10 and we hope used the default ocsinventory-agent.