Index: trunk/packages/invirt-web/code/validation.py
===================================================================
--- trunk/packages/invirt-web/code/validation.py	(revision 1472)
+++ trunk/packages/invirt-web/code/validation.py	(revision 1473)
@@ -5,4 +5,5 @@
 import re
 import string
+import dns.resolver
 from invirt.database import Machine, NIC, Type, Disk, CDROM, Autoinstall
 from invirt.config import structs as config
@@ -271,9 +272,19 @@
     if machine is not None and name == machine.name:
         return None
-    if not Machine.query().filter_by(name=name).count():
+    try:
+        f = open('/tmp/log', 'a')
+        dns.resolver.query('%s.%s.' % (name, config.dns.domains[0]), 'A')
+        # If the hostname didn't exist, it would have thrown an
+        # exception by now - error out
+        raise InvalidInput('name', name, 'Name is already taken.')
+    except dns.resolver.NXDOMAIN, e:
         if not validMachineName(name):
             raise InvalidInput('name', name, 'You must provide a machine name.  Max 63 chars, alnum plus \'-\', does not begin or end with \'-\'.')
         return name
-    raise InvalidInput('name', name, "Name is already taken.")
+    except InvalidInput:
+        raise
+    except:
+        # Any other error is a validation failure
+        raise InvalidInput('name', name, 'We were unable to verify that this name is available. If you believe this is in error, please contact us at %s' % config.dns.contact)
 
 def testDescription(user, description, machine=None):
Index: trunk/packages/invirt-web/debian/changelog
===================================================================
--- trunk/packages/invirt-web/debian/changelog	(revision 1472)
+++ trunk/packages/invirt-web/debian/changelog	(revision 1473)
@@ -1,2 +1,8 @@
+invirt-web (0.0.5) unstable; urgency=low
+
+  * Add new dependency on python-dns
+
+ -- Evan Broder <broder@mit.edu>  Fri, 31 Oct 2008 22:57:41 -0400
+
 invirt-web (0.0.4) unstable; urgency=low
 
Index: trunk/packages/invirt-web/debian/control
===================================================================
--- trunk/packages/invirt-web/debian/control	(revision 1472)
+++ trunk/packages/invirt-web/debian/control	(revision 1473)
@@ -9,6 +9,7 @@
 Architecture: all
 Depends: ${misc:Depends}, libapache2-mod-fcgid, python-flup,
- python-cheetah, python-simplejson, invirt-database,
+ python-cheetah, python-simplejson, python-dns, invirt-database,
  invirt-vnc-client, kstart, debathena-afs-config, invirt-base,
- libapache2-svn, libapache2-mod-auth-kerb, postfix, subversion, zephyr-clients
+ libapache2-svn, libapache2-mod-auth-kerb, postfix, subversion,
+ zephyr-clients
 Description: the Invirt web interface