Fix domain being None in opensearch results

The domain came from HTTP_HOST which in our nginx configuration is not
set, furthermore other code already uses Site to obtain the domain.

Closes: #541

packages/tests/test_search.py

@@ -67,6 +67,7 @@ def test_sort(client, package):
 def test_packages(client, package):
     response = client.get('/opensearch/packages/')
     assert response.status_code == 200
+    assert 'template="example.com/opensearch/packages/"' in response.content.decode()
 
 
 def test_packages_suggest(client, package):

packages/views/__init__.py

@@ -5,6 +5,7 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import permission_required
 from django.contrib.auth.models import User
+from django.contrib.sites.models import Site
 from django.core.cache import cache
 from django.db.models import Q
 from django.http import HttpResponse, HttpResponseBadRequest
@@ -21,10 +22,10 @@
 @require_safe
 @cache_control(public=True, max_age=86400)
 def opensearch(request):
-    domain = "%s://%s" % (request.scheme, request.META.get('HTTP_HOST'))
+    current_site = Site.objects.get_current()
 
     return render(request, 'packages/opensearch.xml',
-                  {'domain': domain},
+                  {'domain': current_site.domain},
                   content_type='application/opensearchdescription+xml')
 
 

public/views.py

@@ -3,6 +3,7 @@
 from operator import attrgetter
 
 from django.contrib.auth.models import User
+from django.contrib.sites.models import Site
 from django.db.models import Count, Q
 from django.http import HttpResponse
 from django.shortcuts import get_object_or_404, render
@@ -25,12 +26,12 @@ def updates():
     else:
         def updates():
             return get_recent_updates()
-    domain = "%s://%s" % (request.scheme, request.META.get('HTTP_HOST'))
+    current_site = Site.objects.get_current()
     context = {
         'news_updates': News.objects.order_by('-postdate', '-id')[:15],
         'pkg_updates': updates,
         'staff_groups': StaffGroup.objects.all(),
-        'domain': domain,
+        'domain': current_site.domain,
     }
     return render(request, 'public/index.html', context)