Zeroconf support for headless server

.travis.yml

@@ -19,6 +19,9 @@ before_install:
   - sudo apt-get -qq install gstreamer0.10-plugins-bad gstreamer0.10-plugins-ugly
   - sudo apt-get -qq install gstreamer0.10-pulseaudio
   - sudo apt-get -qq install gstreamer0.10-alsa
+  - sudo apt-get -qq install python-avahi
+  - python -c 'import avahi'
+  - python -c 'import dbus'
 # command to install dependencies, e.g. pip install -r requirements.txt --use-mirrors
 install:
   - pip install -r dev_requirements.txt --use-mirrors

requirements.txt

@@ -7,3 +7,4 @@ oauth<1.1
 simplejson<3.4
 tabulate==0.7.2
 yapsy<1.11
+zeroconf<=0.15.1

src/freeseer/framework/announcer.py

@@ -0,0 +1,56 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# freeseer - vga/presentation capture software
+#
+#  Copyright (C) 2014  Free and Open Source Software Learning Centre
+#  http://fosslc.org
+#
+#  This program 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.
+#
+#  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# For support, questions, suggestions or any other inquiries, visit:
+# http://wiki.github.com/Freeseer/freeseer/
+
+import avahi
+import dbus
+
+
+class ServiceAnnouncer:
+    """ServiceAnnouncer publishes Freeseer service over Zeroconf/Avahi protocol"""
+    def __init__(self, name, service, port, txt):
+        """
+        Args:
+            name - instance name i.e Freeseer Host
+            service - service type i.e _freeseer._tcp
+            port - port number
+            txt - List containing strings of information you wish to include.
+        """
+        bus = dbus.SystemBus()
+        server = dbus.Interface(bus.get_object(avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER), avahi.DBUS_INTERFACE_SERVER)
+        self.group = dbus.Interface(bus.get_object(avahi.DBUS_NAME, server.EntryGroupNew()), avahi.DBUS_INTERFACE_ENTRY_GROUP)
+        self.service = service
+        self.name = name
+        self.port = port
+        self.txt = txt
+
+    def advertise(self):
+        """Announces Freeseer service over Zeroconf/Avahi"""
+        self.group.AddService(avahi.IF_UNSPEC, avahi.PROTO_INET, 0,
+                              self.name, self.service, '', '', self.port,
+                              avahi.string_array_to_txt_array(self.txt))
+        self.group.Commit()
+
+    def unpublish(self):
+        """Removes service from Zeroconf/Avahi"""
+        self.group.Reset()

src/freeseer/framework/listener.py

@@ -0,0 +1,64 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# freeseer - vga/presentation capture software
+#
+#  Copyright (C) 2014  Free and Open Source Software Learning Centre
+#  http://fosslc.org
+#
+#  This program 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.
+#
+#  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# For support, questions, suggestions or any other inquiries, visit:
+# http://wiki.github.com/Freeseer/freeseer/
+
+import socket
+from time import sleep
+
+from zeroconf import ServiceBrowser, Zeroconf
+
+
+class Listener(object):
+
+    def __init__(self):
+        self.servers = {}
+
+    def removeService(self, zeroconf, type, name):
+        """Updates dictionary of available freeseer servers"""
+        info = zeroconf.getServiceInfo(type, name)
+        ipaddr = socket.inet_ntoa(info.getAddress())
+        port = info.getPort()
+        del self.servers[(ipaddr, port)]
+
+    def addService(self, zeroconf, type, name):
+        """Updates dictionary of available freeseer servers"""
+        info = zeroconf.getServiceInfo(type, name)
+        if info:
+            ipaddr = socket.inet_ntoa(info.getAddress())
+            port = info.getPort()
+            self.servers[(ipaddr, port)] = {
+                'name': name,
+                'type': type,
+            }
+
+
+def search(timeout):
+    results = []
+    zeroconf = Zeroconf(socket.gethostbyname(socket.gethostname()))
+    listener = Listener()
+    ServiceBrowser(zeroconf, '_freeseer._tcp.local.', listener)
+    sleep(timeout)
+    for (ipaddr, port), value in listener.servers.iteritems():
+        results.append('{}\t{}:{}'.format(value['name'].split('.')[0], ipaddr, port))
+    zeroconf.close()
+    return results

src/freeseer/frontend/cli.py

@@ -27,6 +27,7 @@
 import signal
 import sys
 import textwrap
+from time import sleep
 
 import pygst
 import yapsy
@@ -70,6 +71,7 @@ def setup_parser():
     setup_parser_report(subparsers)
     setup_parser_upload(subparsers)
     setup_parser_server(subparsers)
+    setup_parser_browse(subparsers)
     return parser
 
 
@@ -155,7 +157,13 @@ def setup_parser_upload_youtube(subparsers):
 def setup_parser_server(subparsers):
     """Setup server command parser"""
     parser = subparsers.add_parser("server", help="Setup a freeseer restful server")
-    parser.add_argument("-f", "--filename", type=unicode, help="file to load recordings")
+    parser.add_argument("--filename", type=unicode, help="file to load recordings")
+
+
+def setup_parser_browse(subparsers):
+    """Setup browse command parser"""
+    parsers = subparsers.add_parser('browse', help='Search for freeseer servers on the network')
+    parsers.add_argument('-t', '--timeout', help='Poll for freeseer servers continually', type=int)
 
 
 def parse_args(parser, parse_args=None):
@@ -272,6 +280,13 @@ def parse_args(parser, parse_args=None):
         else:
             launch_server()
 
+    elif args.app == 'browse':
+        if args.timeout:
+            timeout = args.timeout
+            launch_browser(timeout)
+        else:
+            launch_browser()
+
 
 def launch_recordapp():
     """Launch the Recording GUI if no arguments are passed"""
@@ -341,3 +356,14 @@ def launch_server(storage_file="recording_storage"):
     import freeseer.frontend.controller.server as server
 
     server.start_server(storage_file)
+
+
+def launch_browser(timeout=5):
+    """Search for Freeseer hosts on client's network"""
+    import freeseer.framework.listener as listener
+
+    print('Searching for Freeseer Hosts\n')
+    results = listener.search(max(timeout, 5))
+    print('Results:')
+    print('\n'.join(results))
+    sleep(0.1)  # workaround hack. Without sleep(0.1) exception is thrown on shutdown on my ubuntu vm.

src/freeseer/frontend/controller/server.py

@@ -23,21 +23,33 @@
 # http://wiki.github.com/Freeseer/freeseer/
 
 import functools
+import signal
+import sys
 
 from flask import jsonify
 
 from freeseer.frontend.controller import app
+from freeseer.framework.announcer import ServiceAnnouncer
 
 
-def start_server(storage_file):
+def start_server(storage_file, port=7079):
     """Starts the restapi server.
 
     Args:
         storage_file - name of storage file to which you are saving recordings
+        port - the port you wish to broadcast your server on.
     """
 
     app.storage_file_path = storage_file
-    app.run()
+    app.service_announcer = ServiceAnnouncer('Freeseer Host', '_freeseer._tcp', port, [])
+    app.service_announcer.advertise()
+    signal.signal(signal.SIGTERM, remove)
+    app.run('::0.0.0.0', port)
+
+
+def remove(signal, frame):
+    app.service_announcer.remove_service()
+    sys.exit(0)
 
 
 def http_response(status_code):