Changeset 750 for trunk/DNSDB.pm

Timestamp:

05/29/17 17:05:18 (7 years ago)

Author:

Kris Deugau

Message:

/trunk

Start adding support for "root CNAME" or "apex alias" records:

• record export
• type definition for SQL

Instead of overloading "true" CNAME handling, we'll follow one existing
path and create a managed pseudotype ALIAS instead.

See #55.

File:

• trunk/DNSDB.pm (modified) (1 diff)

trunk/DNSDB.pm

@@ -6654 +6654 @@
     }
 
+  } elsif ($type == 65300) { # ALIAS
+    # Implemented as a unique record in parallel with many other
+    # management tools, for clarity VS formal behviour around CNAME
+    # Mainly for "root CNAME" or "apex alias";  limited value for any
+    # other use case since CNAME can generally be used elsewhere.
+
+    # .arpa zones don't need this hack.  shouldn't be allowed into
+    # the DB in the first place, but Just In Case...
+    return if $revrec eq 'y';
+
+    my ($target,$iplist) = split /:/, $val, 2;
+    my $res = Net::DNS::Resolver->new;
+    my $reply = $res->query($target);
+
+    if ($reply) { 
+      my $liveips;
+      my @newlist;
+      foreach my $rr ($reply->answer) {  #@alist) {
+        next unless $rr->type eq "A";
+        push @newlist, $rr->address;
+      }
+      # we don't need this to be perfectly correct IP address order, just consistent.
+      $liveips = join(':', sort(@newlist));
+      if ($iplist ne $liveips) {
+        # update the cache of IPs from the target
+        $self->{dbh}->do("UPDATE records SET val=? WHERE record_id=?", undef, "$target:$liveips", $recid);
+        $iplist = $liveips;
+      }
+    } else {
+      warn "Failure retrieving IP list for cache validation/update on ALIAS '$host -> $target': ", $res->errorstring, "\n";
+    }
+
+    # output a plain old A record for each IP the target name really points to.
+    foreach my $subip (split ':', $iplist) {
+      print "+$host:$subip:$ttl,$stamp,$loc\n" or die $!;
+    }
+
 ##
 ## Uncommon types.  These will need better UI support Any Day Sometime Maybe(TM).