Option to clear Django cache

bookwyrm/templates/settings/redis.html

@@ -33,19 +33,67 @@
     </div>
 </section>
 
-<section>
-    {{ dead_key_count }}
-    <form name="erase-keys" method="POST" action="{% url 'settings-redis' %}">
-        {% csrf_token %}
-        <button type="submit" class="button">go</button>
-    </form>
-    <form name="erase-keys" method="POST" action="{% url 'settings-redis' %}">
-        {% csrf_token %}
-        <input type="hidden" name="dry_run" value="True">
-        <button type="submit" class="button">dry run</button>
-    </form>
+<section class="block content">
+    <h2>{% trans "Outdated cache keys" %}</h2>
+    <div class="box">
+        <p>
+        {% blocktrans trimmed %}
+        This will scan for keys in the Django redis cache that use no prefix (the current prefix is <code>{{ prefix }}</code>), and identify Activity Streams for users with deleted accounts.
+        {% endblocktrans %}
+        </p>
+
+        {% if outdated_identified is not None %}
+            <p class="notification has-text-weight-bold">
+            {% blocktrans trimmed with keys=outdated_identified|intcomma %}
+                {{ keys }} identified
+            {% endblocktrans %}
+            </p>
+
+            {% if outdated_identified > 0 %}
+            <form name="erase-keys" method="POST" action="{% url 'settings-redis' %}">
+                {% csrf_token %}
+                <button type="submit" class="button is-danger">{% trans "Erase outdated keys" %}</button>
+            </form>
+            {% endif %}
+        {% else %}
+        <form name="erase-keys" method="POST" action="{% url 'settings-redis' %}">
+            {% csrf_token %}
+                <input type="hidden" name="dry_run" value="True">
+                <button type="submit" class="button">
+                    {% trans "Scan for outdated keys" %}
+                </button>
+        </form>
+        {% endif %}
+    </div>
 </section>
+
+<section class="block content">
+    <h2>{% trans "Clear Django cache" %}</h2>
+    <div class="box">
+        <p>
+        {% blocktrans trimmed %}
+        This is <strong>NOT recommended</strong> and should only be used if something has gone very wrong with your cache. All sessions will be cleared and users will be logged out of their accounts.
+        {% endblocktrans %}
+        </p>
+
+        {% if cache_deleted %}
+            <p class="notification has-text-weight-bold">
+            {% blocktrans trimmed with keys=cache_deleted|intcomma %}
+                {{ keys }} keys deleted
+            {% endblocktrans %}
+            </p>
+        {% else %}
+            <form name="erase-keys" method="POST" action="{% url 'settings-redis' %}">
+                {% csrf_token %}
+                <input type="hidden" name="erase_cache" value="True">
+                <button type="submit" class="button is-danger">{% trans "Erase cache" %}</button>
+            </form>
+        {% endif %}
+    </div>
+</section>
+
 {% else %}
+
 <div class="notification is-danger is-flex is-align-items-start">
     <span class="icon icon-warning is-size-4 pr-3" aria-hidden="true"></span>
     <span>

bookwyrm/views/admin/redis.py

@@ -21,12 +21,7 @@ class RedisStatus(View):
 
     def get(self, request):
         """See workers and active tasks"""
-        data = {"errors": []}
-        try:
-            data["info"] = r.info
-        # pylint: disable=broad-except
-        except Exception as err:
-            data["errors"].append(err)
+        data = view_data()
 
         return TemplateResponse(request, "settings/redis.html", data)
 
@@ -34,19 +29,39 @@ class RedisStatus(View):
     def post(self, request):
         """Erase invalid keys"""
         dry_run = request.POST.get("dry_run")
-        patterns = [":*:*"]  # this pattern is a django cache with no prefix
-        for user_id in models.User.objects.filter(
-            is_deleted=True, local=True
-        ).values_list("id", flat=True):
-            patterns.append(f"{user_id}-*")
+        erase_cache = request.POST.get("erase_cache")
+        data_key = "cache" if erase_cache else "outdated"
+
+        if erase_cache:
+            patterns = [f"{settings.CACHE_KEY_PREFIX}:*:*"]
+        else:
+            patterns = [":*:*"]  # this pattern is a django cache with no prefix
+            for user_id in models.User.objects.filter(
+                is_deleted=True, local=True
+            ).values_list("id", flat=True):
+                patterns.append(f"{user_id}-*")
 
         deleted_count = 0
         for pattern in patterns:
             deleted_count += erase_keys(pattern, dry_run=dry_run)
 
+        data = view_data()
         if dry_run:
-            return HttpResponse(f"{deleted_count} keys identified for deletion")
-        return HttpResponse(f"{deleted_count} keys deleted")
+            data[f"{data_key}_identified"] = deleted_count
+        else:
+            data[f"{data_key}_deleted"] = deleted_count
+        return TemplateResponse(request, "settings/redis.html", data)
+
+
+def view_data():
+    """Helper function to load basic info for the view"""
+    data = {"errors": [], "prefix": settings.CACHE_KEY_PREFIX}
+    try:
+        data["info"] = r.info
+    # pylint: disable=broad-except
+    except Exception as err:
+        data["errors"].append(err)
+    return data
 
 
 def erase_keys(pattern, count=1000, dry_run=False):