tor: Run configuration update as background task

- Closes: #294.

actions/tor

@@ -309,8 +309,6 @@ def _update_ports():
 
     # port information may not be available immediately after Tor started
     while not ready:
-        time.sleep(5)
-
         ports = get_ports()
         ready = 'orport' in ports and 'obfs3' in ports and 'obfs4' in ports
         if ready:
@@ -319,6 +317,7 @@ def _update_ports():
         tries += 1
         if tries >= 12:
             return
+        time.sleep(10)
 
     lines = """<?xml version="1.0" encoding="utf-8"?>
 <service>

plinth/modules/tor/templates/tor.html

@@ -21,6 +21,15 @@
 {% load bootstrap %}
 {% load i18n %}
 
+{% block page_head %}
+
+  {% if config_running %}
+    <meta http-equiv="refresh" content="3" />
+  {% endif %}
+
+{% endblock %}
+
+
 {% block content %}
 
   <h2>{% trans "Anonymity Network (Tor)" %}</h2>
@@ -38,89 +47,100 @@
 
   <h3>{% trans "Status" %}</h3>
 
-  <p class="running-status-parent">
-    {% if status.is_running %}
+  {% if config_running %}
+
+    <p class="running-status-parent">
       <span class="running-status active"></span>
-      {% trans "Tor is running" %}
-    {% else %}
-      <span class="running-status inactive"></span>
-      {% trans "Tor is not running" %}
+      {% trans "Tor configuration is being updated" %}
+    </p>
+
+  {% else %}
+
+    <p class="running-status-parent">
+      {% if status.is_running %}
+        <span class="running-status active"></span>
+        {% trans "Tor is running" %}
+      {% else %}
+        <span class="running-status inactive"></span>
+        {% trans "Tor is not running" %}
+      {% endif %}
+    </p>
+
+    {% include "diagnostics_button.html" with module="tor" %}
+
+    {% if status.hs_enabled %}
+      <div class="row">
+        <div class="col-sm-3">
+          <table class="table table-bordered table-condensed table-striped">
+            <thead>
+              <tr>
+                <th>{% trans "Hidden Service" %}</th>
+                <th>{% trans "Port" %}</th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr>
+                <td>{{ status.hs_hostname }}</td>
+                <td>{{ status.hs_ports }}</td>
+              </tr>
+            </tbody>
+          </table>
+        </div>
+      </div>
     {% endif %}
-  </p>
 
-  {% include "diagnostics_button.html" with module="tor" %}
+    <h3>{% trans "Configuration" %}</h3>
+
+    <form class="form" method="post">
+      {% csrf_token %}
+
+      {{ form|bootstrap }}
+
+      <input type="submit" class="btn btn-primary btn-md"
+             value="{% trans "Update setup" %}"/>
+    </form>
+
+    <h3>{% trans "Bridge" %}</h3>
+
+    <p>
+      {% blocktrans trimmed %}
+        Your {{ box_name }} is configured as a Tor bridge with obfsproxy,
+        so it can help circumvent censorship. If your {{ box_name }} is
+        behind a router or firewall, you should make sure the following
+        ports are open, and port-forwarded, if necessary:
+      {% endblocktrans %}
+    </p>
 
-  {% if status.hs_enabled %}
     <div class="row">
       <div class="col-sm-3">
         <table class="table table-bordered table-condensed table-striped">
           <thead>
             <tr>
-              <th>{% trans "Hidden Service" %}</th>
+              <th>{% trans "Service" %}</th>
               <th>{% trans "Port" %}</th>
             </tr>
           </thead>
           <tbody>
-            <tr>
-              <td>{{ status.hs_hostname }}</td>
-              <td>{{ status.hs_ports }}</td>
-            </tr>
+            {% for name, port in status.ports.items %}
+              <tr>
+                <td>{{ name }}</td>
+                <td>{{ port }}</td>
+              </tr>
+            {% endfor %}
           </tbody>
         </table>
       </div>
     </div>
+
+    <h3>{% trans "SOCKS" %}</h3>
+
+    <p>
+      {% blocktrans trimmed %}
+        A Tor SOCKS port is available on your {{ box_name }} on TCP port
+        9050.
+      {% endblocktrans %}
+    </p>
+
   {% endif %}
 
-  <h3>{% trans "Configuration" %}</h3>
-
-  <form class="form" method="post">
-    {% csrf_token %}
-
-    {{ form|bootstrap }}
-
-    <input type="submit" class="btn btn-primary btn-md"
-           value="{% trans "Update setup" %}"/>
-  </form>
-
-  <h3>{% trans "Bridge" %}</h3>
-
-  <p>
-    {% blocktrans trimmed %}
-      Your {{ box_name }} is configured as a Tor bridge with obfsproxy,
-      so it can help circumvent censorship. If your {{ box_name }} is
-      behind a router or firewall, you should make sure the following
-      ports are open, and port-forwarded, if necessary:
-    {% endblocktrans %}
-  </p>
-
-  <div class="row">
-    <div class="col-sm-3">
-      <table class="table table-bordered table-condensed table-striped">
-        <thead>
-          <tr>
-            <th>{% trans "Service" %}</th>
-            <th>{% trans "Port" %}</th>
-          </tr>
-        </thead>
-        <tbody>
-          {% for name, port in status.ports.items %}
-            <tr>
-              <td>{{ name }}</td>
-              <td>{{ port }}</td>
-            </tr>
-          {% endfor %}
-        </tbody>
-      </table>
-    </div>
-  </div>
-
-  <h3>{% trans "SOCKS" %}</h3>
-
-  <p>
-    {% blocktrans trimmed %}
-      A Tor SOCKS port is available on your {{ box_name }} on TCP port
-      9050.
-    {% endblocktrans %}
-  </p>
-
 {% endblock %}

plinth/modules/tor/views.py

@@ -31,6 +31,8 @@ from plinth.modules import tor
 from plinth.modules.names import SERVICES
 from plinth.signals import domain_added, domain_removed
 
+config_process = None
+
 
 def on_install():
     """Setup Tor configuration as soon as it is installed."""
@@ -48,6 +50,9 @@ def index(request):
     """Serve configuration page."""
     status = tor.get_status()
 
+    if config_process:
+        _collect_config_result(request, status)
+
     form = None
 
     if request.method == 'POST':
@@ -63,6 +68,7 @@ def index(request):
     return TemplateResponse(request, 'tor.html',
                             {'title': _('Tor Control Panel'),
                              'status': status,
+                             'config_running': bool(config_process),
                              'form': form})
 
 
@@ -95,25 +101,48 @@ def __apply_changes(request, old_status, new_status):
         arguments.extend(['--apt-transport-tor', arg_value])
 
     if arguments:
-        actions.superuser_run('tor', ['configure'] + arguments)
-        tor.socks_service.notify_enabled(None, new_status['enabled'])
-        tor.bridge_service.notify_enabled(None, new_status['enabled'])
-        messages.success(request, _('Configuration updated'))
+        global config_process
+        if not config_process:
+            config_process = actions.superuser_run(
+                'tor', ['configure'] + arguments, async=True)
     else:
         messages.info(request, _('Setting unchanged'))
 
+
+def _collect_config_result(request, status):
+    """Handle config process completion."""
+    global config_process
+    if not config_process:
+        return
+
+    return_code = config_process.poll()
+
+    # Config process is not complete yet
+    if return_code == None:
+        return
+
+    tor.socks_service.notify_enabled(None, status['enabled'])
+    tor.bridge_service.notify_enabled(None, status['enabled'])
+
     # Update hidden service name registered with Name Services module.
     domain_removed.send_robust(
         sender='tor', domain_type='hiddenservice')
 
-    (hs_enabled, hs_hostname, hs_ports) = tor.get_hs()
-    if tor.is_enabled() and tor.is_running() and hs_enabled and hs_hostname:
+    if status['enabled'] and status['is_running'] and \
+       status['hs_enabled'] and status['hs_hostname']:
         hs_services = []
         for service in SERVICES:
-            if str(service[2]) in hs_ports:
+            if str(service[2]) in status['hs_ports']:
                 hs_services.append(service[0])
 
         domain_added.send_robust(
             sender='tor', domain_type='hiddenservice',
-            name=hs_hostname, description=_('Tor Hidden Service'),
+            name=status['hs_hostname'], description=_('Tor Hidden Service'),
             services=hs_services)
+
+    if not return_code:
+        messages.success(request, _('Configuration updated.'))
+    else:
+        messages.info(request, _('Error occurred during configuration.'))
+
+    config_process = None