basic functionality

DDNS.pm

@@ -2,7 +2,106 @@ package Martnet::DDNS;
 
 use strict;
 use warnings;
+use Net::DNS;
+use File::Temp qw/tempfile/;
 
 our $VERSION = '0.1';
 
+sub new {
+    my $me = shift;
+    my %opts = @_;
+    
+    return bless {
+	'keyfile' => '/etc/bind/Kprivate.invalid.+157+14348.key',
+	%opts
+    }, $me;
+}
+
+sub _fqdn {
+    my ($dom) = @_;
+
+    return $dom . "_vhosts.private.invalid.";
+}
+
+sub _validateOrDie {
+    my ($dom) = @_;
+
+    die "No domain provided"
+	unless $dom;
+    die "Invalid domain name (must end in a dot)"
+	unless ($dom =~ /^[a-zA-Z0-9\.]+\.$/);
+}
+
+sub _lookupOrDie {
+    my ($dom) = @_;
+
+    _validateOrDie($dom);
+    my $fqdn = _fqdn($dom);
+
+    my $res   = Net::DNS::Resolver->new;
+    my $query = $res->query($fqdn, "TXT");
+
+    if ($query) {
+	foreach my $rr (grep { $_->type eq 'TXT' } $query->answer) {
+	    # We found a record; that's all that I care about.
+	    #print $rr->nsdname, "\n";
+	    return 1;
+	}
+    }
+    else {
+	die "query failed: ", $res->errorstring, "\n";
+    }
+
+    die "Failed to find existing DNS record for $fqdn";
+}
+
+sub __docmd {
+    my ($this, $cmd) = @_;
+
+    my ($tmpfh, $filename) = tempfile();
+    close $tmpfh;
+    
+    my $fh;
+    open($fh, "|nsupdate -d -k $this->{keyfile} > $filename")
+	|| die "Can't open nsupdate: $!";
+    
+    print $fh "server localhost\nzone private.invalid.\n$cmd\nshow\nsend\n";
+    close $fh;
+
+    open($fh, $filename) || die "Can't re-open tmpfile $filename: $!";
+    while (<$fh>) {
+	print;
+    }
+    close $fh;
+
+    unlink $filename;
+}
+
+# Add a new vhost domain by adding a DDNS record that the slaves will notice.
+sub addvhost {
+    my ($this, $dom, $master) = @_;
+
+    _validateOrDie($dom);
+    my $fqdn = _fqdn($dom);
+
+    $this->__docmd("update add $fqdn 60 TXT $master");
+    $this->cleanup();
+}
+
+sub delvhost {
+    my ($this, $dom) = @_;
+
+    _lookupOrDie($dom);
+    my $fqdn = _fqdn($dom);
+
+    $this->__docmd("update delete $fqdn TXT");
+    $this->cleanup();
+}
+
+sub cleanup {
+    my ($this) = @_;
+    # Merge the .jnl file in with the domain file
+    system("rndc sync -clean private.invalid");
+}
+
 1;

Makefile.PL

@@ -3,6 +3,9 @@ use ExtUtils::MakeMaker;
 WriteMakefile(
     'NAME'         => 'Martnet::DDNS',
     'VERSION_FROM' => 'DDNS.pm',
-    'PREREQ_PM'    => { Net::DNS => 0.8 },
+    'PREREQ_PM'    => { Net::DNS => 0.8,
+			File::Temp => 0.234,
+			Regexp::Common => 2013031301,
+    },
     'AUTHOR'       => 'Jorj Bauer <jorj@jorj.org>',
     );

bin/addvhost.pl

@@ -0,0 +1,19 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use Martnet::DDNS;
+use Regexp::Common qw/net/;
+
+my $host = shift || die "No vhost provided";
+my $master = shift || die "No master DNS IP provided";
+
+die "Hostname must end in a dot"
+    unless ($host =~ /^[a-zA-Z0-9\.]+\.$/);
+
+my $regex = $RE{net}{IPv4} . '|' . $RE{net}{IPv6};
+die "Master must be an IPv4 or IPv6 address"
+    unless ($master =~ /^$regex$/);
+
+my $ddns = Martnet::DDNS->new();
+$ddns->addvhost($host, $master);

bin/delvhost.pl

@@ -0,0 +1,14 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+use Martnet::DDNS;
+use Regexp::Common qw/net/;
+
+my $host = shift || die "No vhost provided";
+
+die "Hostname must end in a dot"
+    unless ($host =~ /^[a-zA-Z0-9\.]+\.$/);
+
+my $ddns = Martnet::DDNS->new();
+$ddns->delvhost($host);