path: root/lib/OpenSLX/Basics.pm

# Copyright (c) 2006, 2007 - OpenSLX GmbH
#
# This program is free software distributed under the GPL version 2.
# See http://openslx.org/COPYING
#
# If you have any feedback please consult http://openslx.org/feedback and
# send your suggestions, praise, or complaints to feedback@openslx.org
#
# General information about OpenSLX can be found at http://openslx.org/
# -----------------------------------------------------------------------------
# Basics.pm
#	- provides basic functionality of the OpenSLX config-db.
# -----------------------------------------------------------------------------
package OpenSLX::Basics;

use strict;
use warnings;

our (@ISA, @EXPORT, $VERSION);

use Exporter;
$VERSION = 1.01;
@ISA     = qw(Exporter);

@EXPORT = qw(
	&openslxInit %openslxConfig %cmdlineConfig
	&_tr &trInit
	&warn &die &croak &carp &confess &cluck
	&callInSubprocess &executeInSubprocess &slxsystem
	&vlog
	&checkParams
	&instantiateClass
	&addCleanupFunction &removeCleanupFunction
);

our (%openslxConfig, %cmdlineConfig, %openslxPath);

use subs qw(die warn);

use open ':utf8';

################################################################################
### Module implementation
################################################################################
require Carp;		# do not import anything as we are going to overload carp
					# and croak!
use Carp::Heavy;    # use it here to have it loaded immediately, not at
                    # the time when carp() is being invoked (which might
                    # be at a point in time where the script executes in
                    # a chrooted environment, such that the module can't
                    # be loaded anymore).
use Config::General;
use Encode;
require File::Glob;
use FindBin;
use Getopt::Long;
use POSIX qw(locale_h);

my $translations;

# this hash will hold the active openslx configuration,
# the initial content is based on environment variables or default values.
# Each value may be overridden from config files and/or cmdline arguments.
%openslxConfig = (
	'db-name' => $ENV{SLX_DB_NAME} || 'openslx',
	'db-spec' => $ENV{SLX_DB_SPEC},
	'db-type' => $ENV{SLX_DB_TYPE} || 'SQLite',
	'locale'         => setlocale(LC_MESSAGES),
	'locale-charmap' => `locale charmap`,
	'base-path'      => $ENV{SLX_BASE_PATH} || '/opt/openslx',
	'config-path'    => $ENV{SLX_CONFIG_PATH} || '/etc/opt/openslx',
	'private-path'   => $ENV{SLX_PRIVATE_PATH} || '/var/opt/openslx',
	'public-path'    => $ENV{SLX_PUBLIC_PATH} || '/srv/openslx',
	'temp-path'      => $ENV{SLX_TEMP_PATH} || '/tmp',
	'verbose-level'  => $ENV{SLX_VERBOSE_LEVEL} || '0',

	#
	# options useful during development only:
	#
	'debug-confess' => '0',

	#
	# extended settings follow, which are only supported by slxsettings,
	# but not by any other script:
	#
	'db-user'                            => undef,
	'db-passwd'                          => undef,
	'default-shell'                      => 'bash',
	'default-timezone'                   => 'Europe/Berlin',
	'mirrors-preferred-top-level-domain' => undef,
	'mirrors-to-try-count'               => '20',
	'mirrors-to-use-count'               => '5',
	'ossetup-max-try-count'              => '5',
	'pxe-theme'                          => undef,
	'pxe-theme-menu-margin'              => '9',
);
chomp($openslxConfig{'locale-charmap'});

# specification of cmdline arguments that are shared by all openslx-scripts:
my %openslxCmdlineArgs = (

	# name of database, defaults to 'openslx'
	'db-name=s' => \$cmdlineConfig{'db-name'},

	# full specification of database, a special string defining the
	# precise database to connect to (the contents of this string
	# depend on db-type)
	'db-spec=s' => \$cmdlineConfig{'db-spec'},

	# type of database to connect to (SQLite, mysql, ...), defaults to 'SQLite'
	'db-type=s' => \$cmdlineConfig{'db-type'},

	# activates debug mode, this will show the lines where any error occured
	# (followed by a stacktrace):
	'debug-confess' => \$cmdlineConfig{'debug-confess'},

	# locale to use for translations
	'locale=s' => \$cmdlineConfig{'locale'},

	# locale-charmap to use for I/O (iso-8859-1, utf-8, etc.)
	'locale-charmap=s' => \$cmdlineConfig{'locale-charmap'},

	# file to write logging output to, defaults to STDERR
	'logfile=s' => \$cmdlineConfig{'locale'},

	# path to private data (which is *not* accesible by clients and contains
	# database, vendorOSes and all local extensions [system specific scripts])
	'private-path=s' => \$cmdlineConfig{'private-path'},

	# path to public data (which is accesible by clients and contains
	# PXE-configurations, kernels, initramfs and client configurations)
	'public-path=s' => \$cmdlineConfig{'public-path'},

	# path to temporary data (used during demuxing)
	'temp-path=s' => \$cmdlineConfig{'temp-path'},

	# level of logging verbosity (0-3)
	'verbose-level=i' => \$cmdlineConfig{'verbose-level'},
);

my %cleanupFunctions;

# filehandle used for logging:
my $openslxLog = *STDERR;

$Carp::CarpLevel = 1;

# ------------------------------------------------------------------------------
sub vlog
{
	my $minLevel = shift;
	return if $minLevel > $openslxConfig{'verbose-level'};
	my $str = join("", '-' x $minLevel, @_);
	if (substr($str, -1, 1) ne "\n") {
		$str .= "\n";
	}
	print $openslxLog $str;
	return;
}

# ------------------------------------------------------------------------------
sub openslxInit
{
	# evaluate cmdline arguments:
	Getopt::Long::Configure('no_pass_through');
	GetOptions(%openslxCmdlineArgs);

	# try to read and evaluate config files:
	my $configPath = $cmdlineConfig{'config-path'}
	  || $openslxConfig{'config-path'};
	my $sharePath = "$openslxConfig{'base-path'}/share";
	my $verboseLevel = $cmdlineConfig{'verbose-level'} || 0;
	foreach my $f ("$sharePath/settings.default", "$configPath/settings",
		"$ENV{HOME}/.openslx/settings")
	{
		next unless -e $f;
		if ($verboseLevel >= 2) {
			vlog(0, "reading config-file $f...");
		}
		my $configObject = Config::General->new(
			-AutoTrue       => 1, 
			-ConfigFile     => $f, 
			-LowerCaseNames => 1,
			-SplitPolicy    => 'equalsign',
		);
		my %config = $configObject->getall();
		foreach my $key (keys %config) {
			# N.B.: these config files are used by shell-scripts, too, so in
			# order to comply with shell-style, the config files use shell
			# syntax and an uppercase, underline-as-separator format.
			# Internally, we use lowercase, minus-as-separator format, so we
			# need to convert the environment variable names to our own
			# internal style here (e.g. 'SLX_BASE_PATH' to 'base-path'):
			my $ourKey = $key;
			$ourKey =~ s[^slx_][];
			$ourKey =~ tr/_/-/;
			$openslxConfig{$ourKey} = $config{$key};
		}
	}

	# push any cmdline argument into our config hash, possibly overriding any
	# setting from the config files:
	while (my ($key, $val) = each(%cmdlineConfig)) {
		next unless defined $val;
		$openslxConfig{$key} = $val;
	}

	if (defined $openslxConfig{'logfile'}) {
		open($openslxLog, '>>', $openslxConfig{'logfile'})
		  or croak(
			_tr(
				"unable to append to logfile '%s'! (%s)",    
				$openslxConfig{'logfile'}, $!
			)
		  );
	}
	if ($openslxConfig{'verbose-level'} >= 2) {
		foreach my $key (sort keys %openslxConfig) {
			my $val = $openslxConfig{$key} || '';
			vlog(2, "config-dump: $key = $val");
		}
	}

	# setup translation "engine":
	trInit();

	return 1;
}

# ------------------------------------------------------------------------------
sub trInit
{
	# activate automatic charset conversion on all the standard I/O streams,
	# just to give *some* support to shells in other charsets:
	binmode(STDIN,  ":encoding($openslxConfig{'locale-charmap'})");
	binmode(STDOUT, ":encoding($openslxConfig{'locale-charmap'})");
	binmode(STDERR, ":encoding($openslxConfig{'locale-charmap'})");

	my $locale = $openslxConfig{'locale'};
	if (lc($locale) eq 'c') {
		# treat locale 'c' as equivalent for 'posix':
		$locale = 'posix';
	}

	if (lc($locale) ne 'posix') {
		# parse locale and canonicalize it (e.g. to 'de_DE') and generate
		# two filenames from it (language+country and language only):
		if ($locale !~ m{^\s*([^_]+)(?:_(\w+))?}) {
			die "locale $locale has unknown format!?!";
		}
		my @locales;
		if (defined $2) {
			push @locales, lc($1) . '_' . uc($2);
		}
		push @locales, lc($1);

		# try to load any of the Translation modules (starting with the more
		# specific one [language+country]):
		my $loadedTranslationModule;
		foreach my $trName (@locales) {
			vlog(2,	"trying to load translation module $trName...");
			my $trModule = "OpenSLX/Translations/$trName.pm";
			my $trModuleSpec = "OpenSLX::Translations::$trName";
			if (eval { require $trModule } ) {
				# copy the translations available in the given locale into our 
				# hash:
				$translations = $trModuleSpec->getAllTranslations();
				$loadedTranslationModule = $trModule;
				vlog(
					1,
					_tr(
						"translations module %s loaded successfully", $trModule
					)
				);
				last;
			}
		}
		if (!defined $loadedTranslationModule) {
			vlog(1,
				"unable to load any translations module for locale '$locale' ($!)."
			);
		}
	}
	return;
}

# ------------------------------------------------------------------------------
sub _tr
{
	my $trOrig = shift;

	my $trKey = $trOrig;
	$trKey =~ s[\n][\\n]g;
	$trKey =~ s[\t][\\t]g;

	my $formatStr;
	if (defined $translations) {
		$formatStr = $translations->{$trKey};
	}
	if (!defined $formatStr) {
		$formatStr = $trOrig;
	}
	return sprintf($formatStr, @_);
}

# ------------------------------------------------------------------------------
sub callInSubprocess
{
	my $childFunc = shift;

	my $pid = fork();
	if (!$pid) {

		# child...
		# ...execute the given function and exit:
		my $ok = eval { $childFunc->(); 1 };
		if (!$ok) {
			print STDERR "*** $@";
			exit 5;
		}
		exit 0;
	}

	# parent...
	# ...pass on interrupt- and terminate-signals to child...
	local $SIG{INT}  = sub { kill 'INT',  $pid; waitpid($pid, 0); exit $? };
	local $SIG{TERM} = sub { kill 'TERM', $pid; waitpid($pid, 0); exit $? };

	# ...and wait for child to do its work:
	waitpid($pid, 0);
	if ($?) {
		exit $?;
	}
	return;
}

# ------------------------------------------------------------------------------
sub executeInSubprocess
{
	my @cmdlineArgs = @_;

	my $pid = fork();
	if (!$pid) {

		# child...
		# ...exec the given cmdline:
		exec(@cmdlineArgs);
	}

	# parent...
	return $pid;
}

# ------------------------------------------------------------------------------
sub addCleanupFunction
{
	my $name = shift;
	my $func = shift;

	$cleanupFunctions{$name} = $func;
	return;
}

# ------------------------------------------------------------------------------
sub removeCleanupFunction
{
	my $name = shift;

	delete $cleanupFunctions{$name};
	return;
}

# ------------------------------------------------------------------------------
sub invokeCleanupFunctions
{
	my @funcNames = keys %cleanupFunctions;
	foreach my $name (@funcNames) {
		vlog(2, "invoking cleanup function '$name'...");
		$cleanupFunctions{$name}->();
	}
	return;
}

# ------------------------------------------------------------------------------
sub slxsystem
{
	vlog(2, _tr("executing: %s", join ' ', @_));
	my $res = system(@_);
	if ($res > 0) {
		# check if child got killed, if so we stop, too (unless the signal is
		# SIGPIPE, which we ignore in order to loop over failed FTP connections
		# and the like):
		my $signalNo = $res & 127;
		if ($signalNo > 0 && $signalNo != 13) {
			die _tr("child-process reveived signal '%s', parent stops!",
				$signalNo);
		}
	}
	return $res;
}

# ------------------------------------------------------------------------------
sub cluck
{
	_doThrowOrWarn('cluck', @_);
	return;
}

# ------------------------------------------------------------------------------
sub carp
{
	_doThrowOrWarn('carp', @_);
	return;
}

# ------------------------------------------------------------------------------
sub warn
{
	_doThrowOrWarn('warn', @_);
	return;
}

# ------------------------------------------------------------------------------
sub confess
{
	invokeCleanupFunctions();
	_doThrowOrWarn('confess', @_);
	return;
}

# ------------------------------------------------------------------------------
sub croak
{
	invokeCleanupFunctions();
	_doThrowOrWarn('croak', @_);
	return;
}

# ------------------------------------------------------------------------------
sub die
{
	invokeCleanupFunctions();
	_doThrowOrWarn('die', @_);
	return;
}

# ------------------------------------------------------------------------------
sub _doThrowOrWarn
{
	my $type = shift;
	my $msg = shift;
	
	# use '°°°' for warnings and '***' for errors
	if ($type eq 'carp' || $type eq 'warn' || $type eq 'cluck') {
		$msg =~ s[^°°° ][]igms;
		$msg =~ s[^][°°° ]igms;
	}
	else {
		$msg =~ s[^\*\*\* ][]igms;
		$msg =~ s[^][*** ]igms;
	}

	if ($openslxConfig{'debug-confess'}) {
		my %functionFor = (
			'carp' => sub { Carp::cluck @_ },
			'cluck' => sub { Carp::cluck @_ },
			'confess' => sub { Carp::confess @_ },
			'croak' => sub { Carp::confess @_ },
			'die' => sub { Carp::confess @_ },
			'warn' => sub { Carp::cluck @_ },
		);
		my $func = $functionFor{$type};
		$func->($msg);
	}
	else {
		chomp $msg;
		my %functionFor = (
			'carp' => sub { Carp::carp @_ },
			'cluck' => sub { Carp::cluck @_ },
			'confess' => sub { Carp::confess @_ },
			'croak' => sub { Carp::croak @_ },
			'die' => sub { CORE::die @_},
			'warn' => sub { CORE::warn @_ },
		);
		my $func = $functionFor{$type};
		$func->("$msg\n");
	}
	return;
}

=item checkParams()

Utility function that can be used by any method that accepts param-hashes
to check if the given parameters actually match the expectations.

Each individual parameter has a specification that describes the expectation
that the calling function has towards this param. The following specifications
are supported:

* '!'          - the parameter is required
* '?'          - the parameter is optional
* 'm{regex}'   - the parameter must match the given regex
* '!class=...' - the parameter is required and must be an object of the given class
* '?class=...' - if the parameter has been given, it must be an object of the given class

The function will confess for any unknown, missing, or non-matching param.

If accepted as useful, this function could be moved to a utility module of
the framework in order to be available to all other OTRS-modules.

=cut

sub checkParams
{
    my $params     = shift or confess('need to pass in params-hashref!');
    my $paramsSpec = shift or confess('need to pass in params-spec-hashref!');

    # print a warning for any unknown parameters that have been given:
    my @unknownParams
        =   grep { !exists $paramsSpec->{$_}; }
            keys %$params;
    if (@unknownParams) {
        my $unknownParamsStr = join ',', @unknownParams;
        confess("Enocuntered unknown params: '$unknownParamsStr'!\n");
    }

    # check if all required params have been specified:
    foreach my $param (keys %$paramsSpec) {
        my $spec = $paramsSpec->{$param};
        if (ref($spec) eq 'HASH') {
            # Handle nested specs by recursion:
            my $subParams = $params->{$param};
            if (!defined $subParams) {
                confess("Required param '$param' is missing!");
            }
            checkParams($subParams, $spec);
        }
        elsif (ref($spec) eq 'ARRAY') {
            # Handle nested spec arrays by looped recursion:
            my $subParams = $params->{$param};
            if (!defined $subParams) {
                confess("Required param '$param' is missing!");
            }
            elsif (ref($subParams) ne 'ARRAY') {
                confess("Value for param '$param' must be an array-ref!");
            }
            foreach my $subParam (@$subParams) {
                checkParams($subParam, $spec->[0]);
            }
        }
        elsif ($spec eq '!') {
            # required parameter:
            if (!exists $params->{$param}) {
                confess("Required param '$param' is missing!");
            }
        }
        elsif ($spec =~ m{^\!class=(.+)$}i) {
            my $class = $1;
            # required parameter ...
            if (!exists $params->{$param}) {
                confess("Required param '$param' is missing!");
            }
            # ... of specific class
            if (!$params->{$param}->isa($class)) {
                confess("Param '$param' is not a '$class', but that is required!");
            }
        }
        elsif ($spec eq '?') {
            # optional parameter - nothing to do
        }
        elsif ($spec =~ m{^\?class=(.+)$}i) {
            my $class = $1;
            # optional parameter ...
            if (exists $params->{$param}) {
                # ... has been given, so it must match specific class
                if (!$params->{$param}->isa($class)) {
                    confess("Param '$param' is not a '$class', but that is required!");
                }
            }
        }
        elsif ($spec =~ m{^m{(.+)}$}) {
            # try to match given regex:
            my $regex = $1;
            my $value = $params->{$param};
            if ($value !~ m{$regex}) {
                confess("Required param '$param' isn't matching regex '$regex' (given value was '$value')!");
            }
        }
        else {
            # complain about unknown spec:
            confess("Unknown param-spec '$spec' encountered!");
        }
    }

    return scalar 1;
}

# ------------------------------------------------------------------------------
sub instantiateClass
{
	my $class = shift;
	my $flags = shift || {};

	checkParams($flags, { 
		'pathToClass' => '?', 
		'version'     => '?' 
	});
	my $pathToClass      = $flags->{pathToClass};
	my $requestedVersion = $flags->{version};

	my $moduleName = defined $pathToClass ? "$pathToClass/$class" : $class;
	$moduleName =~ s[::][/]g;
	$moduleName .= '.pm';
	unless (eval { require $moduleName } ) {
		if ($! == 2) {
			die _tr("Module '%s' not found!\n", $moduleName);
		}
		else {
			die _tr("Unable to load module '%s' (%s)\n", $moduleName, $@);
		}
	}
	if (defined $requestedVersion) {
		my $classVersion = $class->VERSION;
		if ($classVersion < $requestedVersion) {
			die _tr(
				'Could not load class <%s> (Version <%s> required, but <%s> found)',
				$class, $requestedVersion, $classVersion);
		}
	}
	return $class->new;
}

1;