Ticket #8: autodiscovery4

diff --git a/pydra_server/cluster/amf/interface.py b/pydra_server/cluster/amf/interface.py
index 0df523b..f19840a 100644
--- a/pydra_server/cluster/amf/interface.py
+++ b/pydra_server/cluster/amf/interface.py
@@ -211,6 +211,20 @@ class AMFInterface(pb.Root):
         """
         return self.master._running
 
+    @authenticated
+    def list_known_nodes(self, _):
+        """
+        list know_nodes
+        """
+        # cast to list, doesn't seem to digest set
+        return list(self.master.known_nodes)
+
+    @authenticated
+    def connect(self, _):
+        """
+        allows the gui to make the master aware of the new node without restart
+        """
+        return self.master.connect()
 
     @authenticated
     def run_task(self, _, task_key, args=None):
diff --git a/pydra_server/cluster/auth/master_avatar.py b/pydra_server/cluster/auth/master_avatar.py
index e0e750e..6bf9d99 100644
--- a/pydra_server/cluster/auth/master_avatar.py
+++ b/pydra_server/cluster/auth/master_avatar.py
@@ -38,6 +38,13 @@ class MasterAvatar(RSAAvatar):
         logger.info('Master connected to node')
 
 
+    def perspective_get_key(self):
+        """
+        Return the node's public key, so we can do a duplicate detection on the
+        master side
+        """
+        return self.chunks()
+
     def save_key(self, json_key):
         """
         Callback to save public key from the master        
diff --git a/pydra_server/cluster/auth/rsa_auth.py b/pydra_server/cluster/auth/rsa_auth.py
index 230c1c2..f9767be 100644
--- a/pydra_server/cluster/auth/rsa_auth.py
+++ b/pydra_server/cluster/auth/rsa_auth.py
@@ -142,13 +142,19 @@ class RSAAvatar(pb.Avatar):
         #send the nodes public key.  serialize it and encrypt it
         #the key must be broken into chunks for it to be signed
         #for ease recompiling it we'll store the chunks as a list
+        key_chunks = []
+        for i in self.chunks():
+            enc = self.client_key.encrypt(i, None)
+            key_chunks.append(enc[0])
+
+        return key_chunks
+        
+    def chunks(self):
         json_key = simplejson.dumps(self.server_pub_key)
         key_chunks = []
         chunk = 128
         for i in range(int(math.ceil(len(json_key)/(chunk*1.0)))):
-            enc = self.client_key.encrypt(json_key[i*chunk:i*chunk+chunk], None)
-            key_chunks.append(enc[0])
-
+            key_chunks.append(json_key[i*chunk:i*chunk+chunk])
         return key_chunks
 
 
diff --git a/pydra_server/cluster/master.py b/pydra_server/cluster/master.py
index ef16f30..8859448 100755
--- a/pydra_server/cluster/master.py
+++ b/pydra_server/cluster/master.py
@@ -46,6 +46,12 @@ import datetime
 
 from threading import Lock
 
+# should be executed before any other reactor stuff to prevent from using non
+# glib2 event loop which we need for dbus
+
+from twisted.internet import glib2reactor
+glib2reactor.install()
+
 from zope.interface import implements
 from twisted.cred import portal, checkers
 from twisted.spread import pb
@@ -56,6 +62,8 @@ from twisted.web import server, resource
 from twisted.cred import credentials
 from django.utils import simplejson
 import settings
+import dbus, avahi
+from dbus.mainloop.glib import DBusGMainLoop
 
 from pydra_server.models import Node, TaskInstance
 from pydra_server.cluster.constants import *
@@ -123,6 +131,7 @@ class Master(object):
         #cluster management
         self.workers = {}
         self.nodes = self.load_nodes()
+        self.known_nodes = set()
         self._workers_idle = []
         self._workers_working = {}
 
@@ -143,6 +152,54 @@ class Master(object):
 
         self.host = 'localhost'
         self.port = 18800
+        self.autodiscovery()
+
+    def autodiscovery(self, callback=None):
+        """
+        set up the dbus loop, and add the callbacks for adding nodes on the fly
+
+        based on http://avahi.org/wiki/PythonBrowseExample
+        """
+        from pydra_server.models import pydraSettings
+
+        def service_resolved(*args):
+            # at this point we have all the info about the node we need
+            if pydraSettings.multicast_all:
+
+                # add the node (without the restart)
+                Node.objects.create(host=args[7], port=args[8])
+                self.connect()
+            else:
+                self.known_nodes.add((args[7], args[8]))
+
+        def print_error(*args):
+            logger.info("Couldn't resolve avahi name: %s" % str(args))
+
+        def node_found(interface, protocol, name, stype, domain, flags):
+            if flags & avahi.LOOKUP_RESULT_LOCAL:
+                    # local service, skip
+                    pass
+
+            server.ResolveService(interface, protocol, name, stype,
+                domain, avahi.PROTO_UNSPEC, dbus.UInt32(0),
+                reply_handler=service_resolved, error_handler=print_error)
+
+
+        # initialize dbus stuff needed for discovery
+        loop = DBusGMainLoop()
+
+        bus = dbus.SystemBus(mainloop=loop)
+
+        server = dbus.Interface( bus.get_object(avahi.DBUS_NAME, '/'),
+                'org.freedesktop.Avahi.Server')
+
+        sbrowser = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
+                server.ServiceBrowserNew(avahi.IF_UNSPEC,
+                    avahi.PROTO_UNSPEC, '_pydra._tcp', 'local', dbus.UInt32(0))),
+                avahi.DBUS_INTERFACE_SERVICE_BROWSER)
+
+        sbrowser.connect_to_signal("ItemNew", node_found)
+
 
     def get_services(self):
         """
@@ -215,6 +272,13 @@ class Master(object):
         with self._lock:
             self.connecting=True
 
+            # make sure the verious states are in sync
+            for i in Node.objects.all():
+                if i.id not in self.nodes:
+                    self.nodes[i.id] = i
+                if (i.host, i.port) in self.known_nodes:
+                    self.known_nodes.discard((i.host, i.port))
+
             "Begin the connection process"
             connections = []
             self.attempts = []
@@ -261,14 +325,10 @@ class Master(object):
             if result[0]:
                 # save reference for remote calls
                 node.ref = result[1]
+                d = node.ref.callRemote('get_key')
+                d.addCallback(self.check_node, node)
 
 
-                logger.info('node:%s:%s - connected' % (node.host, node.port))
-
-                # Authenticate with the node
-                pub_key = node.load_pub_key()
-                self.rsa_client.auth(node.ref, self.receive_key_node, server_key=pub_key, node=node)
-
             #failures
             else:
                 logger.error('node:%s:%s - failed to connect' % (node.host, node.port))
@@ -283,6 +343,21 @@ class Master(object):
         else:
             self.reconnect_count = 0
 
+    def check_node(self, key, node):
+        # node.pub_key is set only for paired nodes, make sure we don't attempt
+        # to pair with a known pub key
+        duplicate = ''.join(key) in [i.pub_key for i in self.nodes.values()]
+        if duplicate and not node.pub_key:
+            logger.info('deleting %s:%s - duplicate' % (node.host, node.port))
+            node.delete()
+            return
+
+        # Authenticate with the node
+        pub_key = node.load_pub_key()
+        self.rsa_client.auth(node.ref, self.receive_key_node, server_key=pub_key, node=node)
+
+        logger.info('node:%s:%s - connected' % (node.host, node.port))
+
 
     def reconnect_nodes(self, reset_counter=False):
         """
diff --git a/pydra_server/cluster/node.py b/pydra_server/cluster/node.py
index d6e9d2a..8b54fb7 100755
--- a/pydra_server/cluster/node.py
+++ b/pydra_server/cluster/node.py
@@ -46,6 +46,8 @@ from twisted.application import service, internet
 
 import os
 from subprocess import Popen
+import platform, dbus, avahi
+from django.utils import simplejson
 from pydra_server.cluster.auth.rsa_auth import load_crypto
 from pydra_server.cluster.auth.master_avatar import MasterAvatar
 
@@ -55,6 +57,45 @@ import settings
 from pydra_server.logging.logger import init_logging
 logger = init_logging(settings.LOG_FILENAME_NODE)
 
+class ZeroconfService:
+    """A simple class to publish a network service with zeroconf using
+    avahi.
+
+    Shamelessly stolen from http://stackp.online.fr/?p=35 
+    """
+
+    def __init__(self, name, port, stype="_http._tcp",
+                 domain="", host="", text=""):
+        self.name = name
+        self.stype = stype
+        self.domain = domain
+        self.host = host
+        self.port = port
+        self.text = text
+
+    def publish(self):
+        bus = dbus.SystemBus()
+        server = dbus.Interface(
+                         bus.get_object(
+                                 avahi.DBUS_NAME,
+                                 avahi.DBUS_PATH_SERVER),
+                        avahi.DBUS_INTERFACE_SERVER)
+
+        g = dbus.Interface(
+                    bus.get_object(avahi.DBUS_NAME,
+                                   server.EntryGroupNew()),
+                    avahi.DBUS_INTERFACE_ENTRY_GROUP)
+
+        g.AddService(avahi.IF_UNSPEC, avahi.PROTO_UNSPEC,dbus.UInt32(0),
+                     self.name, self.stype, self.domain, self.host,
+                     dbus.UInt16(self.port), self.text)
+
+        g.Commit()
+        self.group = g
+
+    def unpublish(self):
+        self.group.Reset()
+
 
 class NodeServer:
     """
@@ -81,6 +122,10 @@ class NodeServer:
         # get information about the server
         self.determine_info()
 
+        service = ZeroconfService(name=platform.node(), port=self.port,
+            stype="_pydra._tcp")
+        service.publish()
+
         logger.info('Node - starting server on port %s' % self.port)
 
 
@@ -142,7 +187,6 @@ class NodeServer:
         Exchange public keys with the master.  This allows the Master
         to authenticate in the future using the keypair handshake
         """
-        from django.utils import simplejson
         from Crypto.PublicKey import RSA
         from twisted.conch.ssh.keys import Key
         import math
diff --git a/pydra_server/models.py b/pydra_server/models.py
index 36644f2..c50ce6e 100644
--- a/pydra_server/models.py
+++ b/pydra_server/models.py
@@ -29,8 +29,9 @@ Settings
 from _mysql_exceptions import ProgrammingError
 try:
     class PydraSettings(dbsettings.Group):
-        host        = dbsettings.StringValue('host', 'IP Address or hostname for this server.  This value will be used by all nodes in the cluster to connect', default='localhost')
-        port        = dbsettings.IntegerValue('port','Port for this server', default=18800)
+        host                = dbsettings.StringValue('host', 'IP Address or hostname for this server.  This value will be used by all nodes in the cluster to connect', default='localhost')
+        port             = dbsettings.IntegerValue('port','Port for this server', default=18800)
+        multicast_all    = dbsettings.BooleanValue('multicast_all', 'Automatically use all the nodes found', default=False)
     pydraSettings = PydraSettings('Pydra')
 
 except ProgrammingError:
diff --git a/pydra_server/templates/discover.html b/pydra_server/templates/discover.html
new file mode 100644
index 0000000..657dae8
--- /dev/null
+++ b/pydra_server/templates/discover.html
@@ -0,0 +1,32 @@
+{% extends "base.html" %}
+<!--
+    Copyright 2009 Oregon State University
+
+    This file is part of Pydra.
+
+    Pydra is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Pydra is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Pydra.  If not, see <http://www.gnu.org/licenses/>.
+-->
+{% block content %}
+{% if known_nodes %}
+    Please put the checkbox next to the Node's you would like to see added and hit submit.
+    <form method="post" action=".">
+    {% for field in known_nodes %}
+        <p>{{ field.0 }}:{{ field.1 }} <input type="checkbox" name="{{ field.0 }}:{{ field.1 }}"></p>
+    {% endfor %}
+    <input type="submit">
+    </form>
+{% else %}
+    There appear to be no non active discovered nodes.
+{% endif %}
+{% endblock %}
diff --git a/pydra_server/templates/header.html b/pydra_server/templates/header.html
index 18c8c71..87249e7 100644
--- a/pydra_server/templates/header.html
+++ b/pydra_server/templates/header.html
@@ -88,7 +88,7 @@
     {% if nodes %}
         <div id="submenu">
             <span class="menuitem"><a class="menuitem" href="{{SITE_ROOT}}/nodes/edit">Create Node</a></span>
-            <span class="menuitem lastmenuitem"><a class="menuitem" href="{{SITE_ROOT}}/nodes/discover">Discover Nodes</a></span>
+            <span class="menuitem lastmenuitem"><a class="menuitem" href="{{SITE_ROOT}}/nodes/discover/">Discover Nodes</a></span>
         </div>
     {% endif %}
     {% if tasks %}
diff --git a/pydra_server/templates/nodes.html b/pydra_server/templates/nodes.html
index 74ba998..5e81472 100644
--- a/pydra_server/templates/nodes.html
+++ b/pydra_server/templates/nodes.html
@@ -281,7 +281,7 @@
 {% block submenu %}
     {% if nodes and perms.pydra_server.can_edit_nodes %}
         <span class="menuitem"><a class="menuitem" href="{{SITE_ROOT}}/nodes/edit">Create Node</a></span>
-        <span class="menuitem lastmenuitem"><a class="menuitem" href="{{SITE_ROOT}}/nodes/discover">Discover Nodes</a></span>
+        <span class="menuitem lastmenuitem"><a class="menuitem" href="{{SITE_ROOT}}/nodes/discover/">Discover Nodes</a></span>
     {% endif %}
 {% endblock %}
 
diff --git a/pydra_server/urls.py b/pydra_server/urls.py
index d81873e..b760d24 100644
--- a/pydra_server/urls.py
+++ b/pydra_server/urls.py
@@ -29,6 +29,7 @@ urlpatterns = patterns('',
 
     # node urls
     (r'^nodes/$', nodes),
+    (r'^nodes/discover/$', discover),
     (r'^nodes/edit/(\d?)$', node_edit),
     (r'^nodes/status/$', node_status),
 
diff --git a/pydra_server/views.py b/pydra_server/views.py
index 9bd0142..92189fd 100644
--- a/pydra_server/views.py
+++ b/pydra_server/views.py
@@ -134,6 +134,25 @@ def node_edit(request, id=None):
     }, context_instance=RequestContext(request, processors=[settings_processor]))
 
 
+@user_passes_test(lambda u: u.has_perm('pydra_server.can_edit_nodes'))
+def discover(request):
+    """
+    allow users to activate the nodes that have been discovered via avahi
+    """
+    from django import forms
+    global pydra_controller
+
+    if request.method == 'POST':
+        reconnect = False
+        for i in request.POST.keys():
+            host, port = i.split(':')
+            if not Node.objects.filter(host=host, port=port):
+                Node.objects.create(host=host, port=port)
+                reconnect = True
+        if reconnect:
+            pydra_controller.remote_connect()
+    return render_to_response('discover.html', {'known_nodes': pydra_controller.remote_list_known_nodes()})
+
 def node_status(request):
     """
     Retrieves Status of nodes
diff --git a/urls.py b/urls.py
index fa916a8..a2723ab 100644
--- a/urls.py
+++ b/urls.py
@@ -26,5 +26,6 @@ admin.autodiscover()
 urlpatterns = patterns('',
     (r'^', include('pydra_server.urls')),
     (r'^admin/(.*)', admin.site.root),
+    (r'^settings/', include('dbsettings.urls')),
 
 )