#! /usr/bin/perl
#
# slxconfig-demuxer - OpenSLX configuration demultiplexer
#
# (c) 2006 - OpenSLX.com
#
# Oliver Tappe <ot@openslx.com>
#
use strict;

my $abstract = q[
slxconfig-demuxer
    This script will read information about all systems, clients and
    groups from the OpenSLX configuration database, mix & match the individual
    configurational attributes and then demultiplex the resulting information
    to a set of configuration files. These files are used by any OpenSLX-client
    during boot to find out which systems to offer for booting.

    The resulting files will be put into the OpenSLX-tftpboot-path (you can use
    the option --tftpboot-path to override the default taken from the OpenSLX
    default settings).

    Please use the --man option in order to read the full manual.
];

use Fcntl qw(:DEFAULT :flock);
use File::Basename;
use Getopt::Long qw(:config pass_through);
use Pod::Usage;

# add the lib-folder and the folder this script lives in to perl's search
# path for modules:
use FindBin;
use lib "$FindBin::RealBin/../lib";
	# production path
use lib "$FindBin::RealBin";
	# development path

use OpenSLX::Basics;
use OpenSLX::ConfigDB qw(:access :aggregation :support);

my $pxeConfigDefaultTemplate = q[# generated by openslx
NOESCAPE 0
PROMPT 0
TIMEOUT 10
DEFAULT menu.c32
IMPLICIT 1
ALLOWOPTIONS 1
MENU TITLE What would you like to do? (use cursor to select)
MENU MASTER PASSWD secret
];

my (
	$dhcpType,
		# type of DHCP export format
	$dryRun,
		# dryRun won't touch any file
	$systemConfCount,
		# number of system configurations written
	$clientSystemConfCount,
		# number of (system-specific) client configurations written
	$helpReq,
	$manReq,
	$versionReq,
);

$dhcpType = 'ISC';

GetOptions(
	'dhcp-type=s' => \$dhcpType,
	'dry-run' => \$dryRun,
	'help|?' => \$helpReq,
	'man' => \$manReq,
	'version' => \$versionReq,
) or pod2usage(2);
pod2usage(-msg => $abstract, -verbose => 0, -exitval => 1) if $helpReq;
pod2usage(-verbose => 2) if $manReq;
if ($versionReq) {
	system('slxversion');
	exit 1;
}

openslxInit();

my $openslxDB = connectConfigDB();

my $clientConfigPath = "$openslxConfig{'private-path'}/config";
if (!-d $clientConfigPath) {
	die _tr("Unable to access client-config-path '%s'!", $clientConfigPath);
}
my $tempPath = "$openslxConfig{'temp-path'}/slxconfig-demuxer";
if (!$dryRun) {
	mkdir $tempPath;
	if (!-d $tempPath) {
		die _tr("Unable to create or access temp-path '%s'!", $tempPath);
	}
}
my $tftpbootPath = $openslxConfig{'tftpboot-path'};
if (!$dryRun) {
	system("rm -rf $tftpbootPath/client-config/* $tftpbootPath/pxe/*");
	system("mkdir -p $tftpbootPath/client-config $tftpbootPath/pxe/pxelinux.cfg");
	if (!-d $tftpbootPath) {
		die _tr("Unable to create or access tftpboot-path '%s'!", $tftpbootPath);
	}
}

my $lockFile = "$tftpbootPath/config-demuxer.lock";
lockScript($lockFile);

writeConfigurations();

my $wr = ($dryRun ? "would have written" : "wrote");
print "$wr $systemConfCount systems and $clientSystemConfCount client-configurations to $tftpbootPath/client-config\n";

disconnectConfigDB($openslxDB);

system("rm -rf $tempPath")		unless $dryRun || length($tempPath) < 12;

unlockScript($lockFile);

exit;

################################################################################
###
################################################################################
sub lockScript
{
	my $lockFile = shift;

	return		if $dryRun;

	# use a lock-file to singularize execution of this script:
	if (-e $lockFile) {
		my $ctime = (stat($lockFile))[10];
		my $now = time();
		if ($now - $ctime > 15*60) {
			# existing lock file is older than 15 minutes, wipe it:
			unlink $lockFile;
		}
	}
	if (!sysopen(LOCKFILE, $lockFile, O_RDWR|O_CREAT|O_EXCL)) {
		if ($! == 13) {
			die _tr(qq[Unable to create lock-file <%s>, exiting!\n], $lockFile);
		} else {
			die _tr(qq[Lock-file <%s> exists, script is already running.
Please remove the logfile and try again if you are sure that no one else
is executing this script.\n], $lockFile);
		}
	}
}

sub unlockScript
{
	my $lockFile = shift;

	return		if $dryRun;

	unlink $lockFile;
}

sub writeAttributesToFile
{
	my $attrHash = shift;
	my $fileName = shift;

	return		if $dryRun;

	open(ATTRS, "> $fileName")		or die "unable to write to $fileName";
	my @attrs = sort grep { isAttribute($_) } keys %$attrHash;
	foreach my $attr (@attrs) {
		if (length($attrHash->{$attr}) > 0) {
			my $externalAttrName = externalAttrName($attr);
			print ATTRS "$externalAttrName=$attrHash->{$attr}\n";
		}
	}
	close(ATTRS);
}

sub copyExternalSystemConfig
{	# copies local configuration extensions of given system from private
	# config folder (var/lib/openslx/config/...) into a temporary folder
	my $systemName = shift;
	my $targetPath = shift;

	return		if $dryRun;

	if ($targetPath !~ m[$tempPath]) {
		die _tr("system-error: illegal target-path <%s>!", $targetPath);
	}
	system("rm -rf $targetPath");
	mkdir $targetPath;

	# first copy default files...
	my $defaultConfigPath = "$clientConfigPath/default";
	if (-d $defaultConfigPath) {
		system("cp -r $defaultConfigPath/* $targetPath");
	}
	# now pour system-specific configuration on top (if any):
	my $systemConfigPath = "$clientConfigPath/$systemName";
	if (-d $systemConfigPath) {
		system("cp -r $systemConfigPath/* $targetPath");
	}
}

sub createTarOfPath
{
	my $buildPath = shift;
	my $tarName = shift;
	my $destinationPath = shift;

	my $tarFile = "$destinationPath/$tarName";
	vlog 1, _tr('creating tar %s', $tarFile);
	return		if $dryRun;

	mkdir $destinationPath;
	my $tarCmd = "cd $buildPath && tar czf $tarFile *";
	if (system("$tarCmd") != 0) {
		die _tr("unable to execute shell-command:\n\t%s \n\t(%s)", $tarCmd, $!);
	}
}

################################################################################
###
################################################################################
sub writePXEMenus
{
	my $pxePath = "$tftpbootPath/pxe";
	my $pxeConfigPath = "$tftpbootPath/pxe/pxelinux.cfg";

	if (!-e "$pxePath/pxelinux.0") {
		my $pxelinux0Path
			= "$openslxConfig{'share-path'}/tftpboot/pxelinux.0";
		system(qq[cp -a "$pxelinux0Path" $pxePath/]);
	}
	if (!-e "$pxePath/menu.c32") {
		my $menuc32Path
			= "$openslxConfig{'share-path'}/tftpboot/menu.c32";
		system(qq[cp -a "$menuc32Path" $pxePath/]);
	}

	my @clients = fetchClientsByFilter($openslxDB);
	foreach my $client (@clients) {
		my $externalClientID = externalIDForClient($client);
		my $pxeFile = "$pxeConfigPath/$externalClientID";
		my $clientAppend = $client->{kernel_params};
		vlog 1, _tr("writing PXE-file %s", $pxeFile);
		open(PXE, "> $pxeFile")		or die "unable to write to $pxeFile";
		print PXE $pxeConfigDefaultTemplate;
		my @systemIDs = aggregatedSystemIDsOfClient($openslxDB, $client);
		my @systems = fetchSystemsByID($openslxDB, \@systemIDs);
		foreach my $system (@systems) {
			my @infos = aggregatedSystemFileInfosOfSystem($openslxDB, $system);
			foreach my $info (@infos) {
				my $extSysID = externalIDForSystem($info);
				my $append = $system->{kernel_params};
				$append .= " initrd=$extSysID/initramfs";
				$append .= " $clientAppend";
				$append .= " rootfs=$info->{'export-uri'} file";
				print PXE "LABEL openslx-$extSysID\n";
#				print PXE "\tMENU DEFAULT\n";
				print PXE "\tMENU LABEL ^$info->{label}\n";
				print PXE "\tKERNEL $extSysID/kernel\n";
				print PXE "\tAPPEND $append\n";
				print PXE "\tIPAPPEND 1\n";
			}
		}
		close(PXE);
 	}
}

sub generateInitalRamFS
{
	my $setup = shift;
	my $vendorOS = shift;
	my $pxeSysPath = shift;

	vlog 1, _tr('generating initialramfs %s/initramfs', $pxeSysPath);
	my $cmd = "$openslxConfig{'bin-path'}/slxmkramfs ";
	if ($setup->{ramfs_use_glibc}) {
		$cmd .= '-g ';
	}
	if ($setup->{ramfs_use_busybox}) {
		$cmd .= '-b ';
	}
	my $debugLevel = $setup->{ramfs_debug_level};
	if ($debugLevel) {
		$cmd .= qq[-d $debugLevel ];
	}
	if (length($setup->{ramfs_nicmods}) > 0) {
		$cmd .= qq[-n "$setup->{ramfs_nicmods}" ];
	}
	if (length($setup->{ramfs_fsmods}) > 0) {
		$cmd .= qq[-f "$setup->{ramfs_fsmods}" ];
	}
	my $rootPath
		= "$openslxConfig{'private-path'}/stage1/$vendorOS->{path}";
	$cmd .= "-i $pxeSysPath/initramfs -r $rootPath";

	$ENV{'SLX_PRIVATE_PATH'} = $openslxConfig{'private-path'};
	$ENV{'SLX_PUBLIC_PATH'} = $openslxConfig{'public-path'};
	$ENV{'SLX_SHARE_PATH'} = $openslxConfig{'share-path'};
	vlog 2, _tr('executing %s', $cmd);
	system($cmd)		unless $dryRun;
}

sub writeSystemPXEFiles
{
	my $system = shift;

	my $pxePath = "$tftpbootPath/pxe";

	my $vendorOS = fetchVendorOSesByID($openslxDB, $system->{vendor_os_id});
	my @infos = aggregatedSystemFileInfosOfSystem($openslxDB, $system);
	foreach my $info (@infos) {
		my $kernelFile = $info->{'kernel-file'};
		my $extSysID = externalIDForSystem($info);
		my $pxeSysPath = "$pxePath/$extSysID";
		if (-e $pxeSysPath) {
			die _tr('PXE-system %s already exists!', $pxeSysPath);
		}
		mkdir $pxeSysPath;
		vlog 1, _tr('copying kernel %s to %s/kernel', $kernelFile, $pxeSysPath);
		system(qq[cp -a "$kernelFile" $pxeSysPath/kernel])		unless $dryRun;

		generateInitalRamFS($info, $vendorOS, $pxeSysPath);
	}
}

sub writeDhcpConfig
{
	return unless defined $dhcpType;
	my $dhcpModule = "OpenSLX::Export::DHCP::$dhcpType";
	if (!eval "require $dhcpModule") {
		die _tr("unable to load DHCP-Export backend '%s'! (%s)\n", $dhcpModule, $@);
	}
	my $dhcpBackend = $dhcpModule->new();
	my @clients = fetchClientsByFilter($openslxDB);
	$dhcpBackend->execute(\@clients);
}

sub writeClientConfigurationsForSystem
{
	my $system = shift;
	my $buildPath = shift;
	my $attrFile = shift;

	my @clientIDs = aggregatedClientIDsOfSystem($openslxDB, $system);
	my @clients = fetchClientsByID($openslxDB, \@clientIDs);
	foreach my $client (@clients) {
		vlog 2, _tr("exporting client %d:%s", $client->{id}, $client->{name});
		$clientSystemConfCount++;

		# merge configurations of client, it's groups, default client and
		# system and write the resulting attributes to a configuration file:
		mergeDefaultAndGroupAttributesIntoClient($openslxDB, $client);
		mergeAttributes($client, $system);
		writeAttributesToFile($client, $attrFile);

		# create tar containing external system configuration
		# and client attribute file:
		my $externalClientID = externalIDForClient($client);
		my $externalSystemID = externalIDForSystem($system);
		createTarOfPath($buildPath, "${externalClientID}.tgz",
						"$tftpbootPath/client-config/$externalSystemID");
	}
}

sub writeSystemConfigurations
{
	my @systems = fetchSystemsByFilter($openslxDB);
	foreach my $system (@systems) {
		next 	unless $system->{id} > 0;

		vlog 2, _tr('exporting system %d:%s', $system->{id}, $system->{name});
		$systemConfCount++;

		my $buildPath = "$tempPath/build";
		copyExternalSystemConfig($system->{name}, $buildPath);

		my $attrFile = "$buildPath/initramfs/machine-setup";
		mergeDefaultAttributesIntoSystem($openslxDB, $system);
		writeAttributesToFile($system, $attrFile);

		my $externalSystemID = externalIDForSystem($system);
		my $systemPath = "$tftpbootPath/client-config/$externalSystemID";
		createTarOfPath($buildPath, "default.tgz", $systemPath);

		writeSystemPXEFiles($system);

		writeClientConfigurationsForSystem($system, $buildPath, $attrFile);

		system("rm -rf $buildPath")		unless $dryRun;
	}
}

sub writeConfigurations
{
	$systemConfCount = $clientSystemConfCount = 0;
	writeSystemConfigurations();
	writePXEMenus();
	writeDhcpConfig();
}

__END__

=head1 NAME

slxconfig-demuxer - OpenSLX configuration demultiplexer

=head1 SYNOPSIS

slxconfig-demuxer [options]

  Script Options:
      --dhpc-type=s              specifies the type of DHCP-server (ISC,...)
      --dry-run                  avoids writing anything, for testing

  OpenSLX Options:
      --base-path=<string>       basic path to project files
      --bin-path=<string>        path to binaries and scripts
      --config-path=<string>     path to configuration files
      --db-basepath=<string>     basic path to openslx database
      --db-datadir=<string>      data folder created under db-basepath
      --db-name=<string>         name of database
      --db-spec=<string>         full DBI-specification of database
      --db-type=<string>         type of database to connect to
      --export-path=<string>     path to root of all exported filesystems
      --locale=<string>          locale to use for translations
      --logfile=<string>         file to write logging output to
      --private-path=<string>    path to private data
      --public-path=<string>     path to public (client-accesible) data
      --share-path=<string>      path to sharable data
      --temp-path=<string>       path to temporary data
      --tftpboot-path=<string>   path to root of tftp-server
      --verbose-level=<int>      level of logging verbosity (0-3)

  General Options:
      --help                     brief help message
      --man                      full documentation
      --version                  show version

=head1 OPTIONS

=head3 Script Options

=over 8

=item B<--dhcp-type>

Specifies the type of DHCP-export that shall be used. Currently, only 'ISC' is
supported.

=item B<--dry-run>

Runs the script but avoids writing anything. This is useful for testing, as
you can learn from the logging output what would have been done.

=back

=head3 OpenSLX Options

=over 8

=item B<--base-path=<string>>

Sets basic path to project files.

Default is $SLX_BASE_PATH (usually F</opt/openslx>).

=item B<--bin-path=<string>>

Sets path to binaries and scripts.

Default is $SLX_BASE_PATH/bin (usually F</opt/openslx/bin>).

=item B<--config-path=<string>>

Sets path to configuration files.

Default is $SLX_CONFIG_PATH (usually F</etc/opt/openslx>).

=item B<--db-basepath=<string>>

Sets basic path to openslx database.

Default is $SLX_DB_PATH (usually F</var/opt/openslx/db>).

=item B<--db-datadir=<string>>

Sets data folder created under db-basepath.

Default is $SLX_DB_DATADIR (usually empty as it depends on db-type
whether or not such a directory is required at all).

=item B<--db-name=<string>>

Gives the name of the database to connect to.

Default is $SLX_DB_NAME (usually C<openslx>).

=item B<--db-spec=<string>>

Gives the full DBI-specification of database to connect to. Content depends
on the db-type.

Default is $SLX_DB_SPEC (usually empty as it will be built automatically).

=item B<--db-type=<string>>

Sets the type of database to connect to (CSV, SQLite, mysql, ...).

Default $SLX_DB_TYPE (usually C<CSV>).

=item B<--export-path=<string>>

Sets path to root of all exported filesystems. For each type of export (NFS,
NBD, ...) a separate folder will be created in here.

Default is $SLX_EXPORT_PATH (usually F</srv/openslx/export>.

=item B<--locale=<string>>

Sets the locale to use for translations.

Defaults to the system's standard locale.

=item B<--logfile=<string>>

Specifies a file where logging output will be written to.

Default is to log to STDERR.

=item B<--private-path=<string>>

Sets path to private data, where the config-db, vendor_oses and configurational
extensions will be stored.

Default is $SLX_PRIVATE_PATH (usually F</var/opt/openslx>.

=item B<--public-path=<string>>

Sets path to public (client-accesible) data.

Default is $SLX_PUBLIC_PATH (usually F</srv/openslx>.

=item B<--share-path=<string>>

Sets path to sharable data, where distro-specs and functionality templates
will be stored.

Default is $SLX_SHARE_PATH (usually F</opt/openslx/share>.

=item B<--temp-path=<string>>

Sets path to temporary data.

Default is $SLX_TEMP_PATH (usually F</tmp>.

=item B<--tftpboot-path=<string>>

Sets path to root of tftp-server from which clients will access their files.

Default is $SLX_TFTPBOOT_PATH (usually F</srv/openslx/tftpboot>.

=item B<--verbose-level=<int>>

Sets the level of logging verbosity (0-3).

Default is $SLX_VERBOSE_LEVEL (usually 0, no logging).

=back

=head3 General Options

=over 8

=item B<--help>

Prints a brief help message and exits.

=item B<--man>

Prints the manual page and exits.

=item B<--version>

Prints the version and exits.

=back

=head1 DESCRIPTION

B<slxconfig-demuxer.pl> will read information about all systems, clients and
groups from the OpenSLX configuration database, mix & match the individual
configurational attributes and then demultiplex the resulting information
to a set of configuration files. These files are used by any OpenSLX-client
during boot to find out which systems to offer for booting.

The resulting files will be put into the OpenSLX-tftpboot-path (you can use the
option B<--tftpboot-path> to override the default taken from the OpenSLX
default settings).

=head2 FILE CREATION

The following set of files will be created:

=over 8

=item B<Basic PXE Setup>

The basic PXE files (F<menu.c32>, F<pxelinux.0>) will be copied into
F<$SLX_TFTPBOOT_PATH/pxe> to make them available to any PXE-client via tftp.

=item B<PXE Client Configurations>

For each client, a PXE configuration file will be generated and written to
F<$SLX_TFTPBOOT_PATH/pxe/pxelinux.cfg/01-<MAC-of-client>>. This file will
contain information about the systems this client shall offer for booting.
For each of these systems, the kernel cmdline options required for that
particular system setup is specified (via PXE's APPEND option).

=item B<System Kernels and Initialram-Filesystems>

For each bootable system, that system's kernel will be copied to
F<$SLX_TFTPBOOT_PATH/pxe/<system-name>/kernel and an OpenSLX-specific initramfs
required for booting that particular system is generated (by means of
slxmkramfs) and put into F<$SLX_TFTPBOOT_PATH/pxe/<system-name>/initramfs.

These two files (kernel & initramfs) will be referenced by the PXE client
configuration of all clients that offer this specific system for booting.

=item B<OpenSLX Client Configurations>

For each combination of system and client, an OpenSLX configuration archive
will be generated and written to
F<$SLX_TFTPBOOT_PATH/client-config/<system-name>/01-<MAC-of-client>.tgz>.
This archive will contain the file F<initramfs/machine-setup>, specifying all
the attributes of that particular client (e.g. whether or not it should start
the X-server).

Furthermore, the archive may contain additional system files that are
required for the client (e.g. a special PAM-module required for LDAP
authentication). These files are copied from F<$SLX_PRIVATE_PATH/config/default>
and F<$SLX_PROVATE_PATH/config/<system-name>>.

=back

=head2 MIXING & MATCHING (THE DEMUXER)

In the OpenSLX configuration database, each system, group and client may have
several configurational attributes set to a specific value that will cause
a client booting that system to behave in a certain way. The mixing of all
these different attributes into one set that is relevant for a specific client
booting one specific system is one important task of the slxconfig-demuxer.

As an example, let's assume one system setup that is configured to boot directly
into a special application that demands a rather low screen-resolution of
1024x768 pixels, as otherwise the text would be unreadable due to very small
fonts being used by that app. In order to achieve this, the administrator can
set the I<hw_monitor>-attribute of the B<system> to '1024x768'.
Let's say one of the clients, however, is connected to a very old monitor that
has problems with this resolution and only supports 800x600 pixels. In that
case, the administrator can set the I<hw_monitor>-attribute of that B<client> to
'800x600'. The mixing & matching process would make sure that this specific
client would run that system with a resolution of 800x600, while all other
clients would run that system in 1024x768.

So the slxconfig-demuxer demultiplexes the individual configurational attributes
into a concrete set of configuration settings for specific clients and their
offered systems, making sure that each client/system combination uses the
appropriate settings.

=cut