Adjust cache TTL for old posts (#545)

Author: simonw

blog/tests.py

@@ -7,6 +7,8 @@
     NoteFactory,
 )
 from blog.models import Tag, PreviousTagName
+from django.utils import timezone
+import datetime
 import json
 
 
@@ -73,6 +75,19 @@ def test_note(self):
         self.assertTemplateUsed(response, "note.html")
         self.assertEqual(response.context["note"].pk, note.pk)
 
+    def test_cache_header_for_old_content(self):
+        old_date = timezone.now() - datetime.timedelta(days=181)
+        entry = EntryFactory(created=old_date)
+        response = self.client.get(entry.get_absolute_url())
+        assert response.headers["cache-control"] == "s-maxage=%d" % (
+            24 * 60 * 60
+        )
+
+    def test_no_cache_header_for_recent_content(self):
+        recent_entry = EntryFactory(created=timezone.now())
+        response = self.client.get(recent_entry.get_absolute_url())
+        assert "cache-control" not in response.headers
+
     def test_archive_year(self):
         quotation = QuotationFactory()
         response = self.client.get("/{}/".format(quotation.created.year))

blog/views.py

@@ -14,6 +14,7 @@
 )
 from django.http import Http404, HttpResponsePermanentRedirect as Redirect, HttpResponse
 from django.test import Client
+from django.utils import timezone
 from .models import (
     Blogmark,
     Entry,
@@ -133,6 +134,10 @@ def archive_item(request, year, month, day, slug):
         )
         if obj.is_draft:
             set_no_cache(response)
+        else:
+            six_months = datetime.timedelta(days=180)
+            if obj.created < timezone.now() - six_months:
+                response["Cache-Control"] = "s-maxage={}".format(24 * 60 * 60)
         response["x-enable-card"] = "1"
         return response