Add hostconfig

Import hostconfig from its own repository mariux64/hostconfig. No need
to import history, because there are only three commits (one import, one
infrastructure and a single change).

hostconfig/hostconfig

@@ -0,0 +1,141 @@
+#! /usr/bin/perl
+use strict;
+use warnings;
+use Getopt::Long;
+
+my %TAGS;		# ( host => { tag=>1, ... }, ... )
+my %options;
+
+$0 =~ /get-hostconfig/ and warn "$0: deprecated. Please use hostconfig\n";
+
+sub read_hostconfig {
+	open my $in,'<','/etc/hostconfig' or die "/etc/hostconfig: $!\n";
+	while (<$in>) {
+		s/#.*//;
+		chomp;
+		my ($host,$attr,$value)=split ' ',$_,3;
+		$host or next;
+		$attr or next;
+		$attr ne 'tag' and $TAGS{$host}->{$attr}=2;
+		$attr eq 'tag' or next;
+		$TAGS{$host}||={};
+		my @tag=split ' ',$value;
+		for my $tag (@tag) {
+			my ($neg,$tag)=$tag=~/^(!?)(.+)/;
+			$neg and next;
+			$TAGS{$host}->{$tag}=1;
+		}
+	}
+}
+
+
+sub evalue_expression {
+
+	my ($hostname,$expression)=@_;
+
+	exists $TAGS{$hostname} or warn "$0: hostname $hostname : no info\n";
+	my $tags=$TAGS{$hostname};
+
+	my @l = grep /\S/,split /([&\|\(\)!]|\s+)/,$expression;
+
+	$options{'debug'} and warn join(' ',map("'$_'",@l)),"\n";
+	for (@l) {
+		s/\s*(.+?)\s*/$1/;
+		if (/^[a-z][a-z0-9$_-]*$/i) {
+			$_=exists $tags->{$_} ? 1 : 0;
+		}
+	}
+	$options{'debug'} and warn join(' ',map("'$_'",@l)),"\n";
+
+	my $result=eval join(' ',@l);
+	$@ and die "$0: syntax error in expression: $expression\n";
+	$options{'debug'}  and warn "result: ".($result ? 'true' : 'false'),"\n";
+
+	return $result;
+}
+
+sub populate_node {
+	my ($hostname)=@_;
+	my $DIR='/node/tags';
+	-d $DIR and system "rm -rf $DIR" and exit 1;
+	mkdir $DIR or die "$DIR: $!\n";
+	my $tags=$TAGS{$hostname};
+	for (keys %$tags) {
+		open my $touch,'>',"$DIR/$_";
+	}	
+}
+
+sub list {
+	my ($expression)=@_;
+	my @ret;
+	for my $hostname (sort keys %TAGS) {
+		if (evalue_expression($hostname,$expression)) {
+			push @ret,$hostname;
+		}
+	}
+	return @ret;
+}
+
+
+sub USAGE {
+	<<"EOF";
+
+  usage: $0 [options]                 - show tags
+         $0 [options] expression...   - evaluate and set exit status
+         $0 --list [options] expression...   - enumerate hosts for which expression is true
+
+         $0 [options] --populate-node - (re-)create /node/tags/
+
+  options:
+
+    --hostname host   : evaluate for another host
+    --debug           : guess what this does
+
+  expressions:
+
+     boolean terms:    tags from hostconfig
+     unary operator:   '!'
+     binary operators: '&','|'
+     precedence:       '(',')'
+
+  expression example:
+  
+    if $0 distmaster                     ;then echo "lala";fi
+    if $0 'mx64 & desktop'               ;then echo "lala";fi
+    if $0 'testing | (mx64b & !desktop)' ;then echo "lala";fi
+
+EOF
+}
+
+my $hostname;
+
+GetOptions
+(
+        'hostname=s'	=>   \$options{'hostname'},
+	'debug'		=>   \$options{'debug'},
+	'populate-node'	=>   \$options{'populate-node'},
+	'list'		=>   \$options{'list'},
+
+) or die USAGE;
+
+chomp($hostname = $options{'hostname'} ? $options{'hostname'} : `uname -n`);$hostname=~s/\..*//;
+read_hostconfig();
+
+my $expression = join ' ',@ARGV;
+
+if ($options{'populate-node'}) {
+	populate_node($hostname);
+} elsif ($options{'list'}) {
+	@ARGV or die USAGE;
+	print join(' ',list($expression)),"\n";
+} else {
+	if (@ARGV) {
+		exit (evalue_expression($hostname,$expression) ? 0 : 1);
+	} else {
+		exists $TAGS{$hostname} or warn "$0: hostname $hostname : no info\n";
+		my $tags=$TAGS{$hostname};
+		print join (' ',sort keys %$tags),"\n";
+	}
+}
+
+

install.sh

@@ -129,4 +129,5 @@ install_exec setuid/setuid                               "$DESTDIR$usr_sbindir/s
 install_exec uvpn/uvpn                                   "$DESTDIR$usr_bindir/uvpn"
 install_exec mxmount/mxmount                             "$DESTDIR$usr_bindir/mxmount"
 install_data mxmount/mxmount.service                     "$DESTDIR$systemdunitdir/mxmount.service"
+install_exec hostconfig/hostconfig                       "$DESTDIR$usr_sbindir/hostconfig"
 exit