Manually delete unused keys from redis activity cache

bookwyrm/settings.py

@@ -243,6 +243,7 @@
 # timeout for a query to an individual connector
 QUERY_TIMEOUT = env.int("INTERACTIVE_QUERY_TIMEOUT", env.int("QUERY_TIMEOUT", 5))
 
+CACHE_KEY_PREFIX = "django_cache"
 # Redis cache backend
 if env.bool("USE_DUMMY_CACHE", False):
     CACHES = {
@@ -259,6 +260,7 @@
         "default": {
             "BACKEND": "django.core.cache.backends.redis.RedisCache",
             "LOCATION": REDIS_ACTIVITY_URL,
+            "KEY_PREFIX": CACHE_KEY_PREFIX,
         },
         "file_resubmit": {
             "BACKEND": "django.core.cache.backends.filebased.FileBasedCache",

bookwyrm/templates/settings/layout.html

@@ -85,6 +85,10 @@ <h2 class="menu-label">{% trans "System" %}</h2>
                 {% url 'settings-celery' as url %}
                 <a href="{{ url }}"{% if url in request.path %} class="is-active" aria-selected="true"{% endif %}>{% trans "Celery status" %}</a>
             </li>
+            <li>
+                {% url 'settings-redis' as url %}
+                <a href="{{ url }}"{% if url in request.path %} class="is-active" aria-selected="true"{% endif %}>{% trans "Redis status" %}</a>
+            </li>
             <li>
                 {% url 'settings-schedules' as url %}
                 <a href="{{ url }}"{% if url in request.path %} class="is-active" aria-selected="true"{% endif %}>{% trans "Scheduled tasks" %}</a>

bookwyrm/templates/settings/redis.html

@@ -0,0 +1,125 @@
+{% extends 'settings/layout.html' %}
+{% load humanize %}
+{% load i18n %}
+
+{% block title %}{% trans "Redis Status" %}{% endblock %}
+
+{% block header %}{% trans "Redis Status" %}{% endblock %}
+
+{% block panel %}
+
+{% if info %}
+<section class="block content">
+    <h2>{% trans "Info" %}</h2>
+    <div class="columns has-text-centered is-multiline">
+        <div class="column is-4">
+            <div class="notification">
+                <p class="header">{% trans "Used memory" %}</p>
+                <p class="title is-5">{{ info.used_memory_human }}</p>
+            </div>
+        </div>
+        <div class="column is-4">
+            <div class="notification">
+                <p class="header">{% trans "Total system memory" %}</p>
+                <p class="title is-5">{{ info.total_system_memory_human }}</p>
+            </div>
+        </div>
+        <div class="column is-4">
+            <div class="notification">
+                <p class="header">{% trans "Keys" %}</p>
+                <p class="title is-5">{{ info.db0.keys | intcomma }}</p>
+            </div>
+        </div>
+    </div>
+</section>
+
+<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="scan-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 "Advanced" %}</h2>
+    <details class="details-panel box">
+        <summary>
+            <span class="title is-5" role="headind" aria-level="3">
+                {% trans "Clear Django Cache" %}
+            </span>
+            <span class="details-close icon icon-x" aria-hidden="true"></span>
+        </summary>
+
+        <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-cache" method="POST" action="{% url 'settings-redis' %}">
+                {% csrf_token %}
+                <input type="hidden" name="erase_cache" value="True">
+                <div class="control">
+                    <button type="submit" class="button is-danger">{% trans "Erase cache" %}</button>
+                </div>
+            </form>
+        {% endif %}
+    </details>
+</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>
+        {% trans "Could not connect to Redis Activity" %}
+    </span>
+</div>
+
+{% endif %}
+
+{% if errors %}
+<div class="block content">
+    <h2>{% trans "Errors" %}</h2>
+    {% for error in errors %}
+    <pre>{{ error }}</pre>
+{% endfor %}
+
+</div>
+{% endif %}
+
+{% endblock %}

bookwyrm/tests/views/admin/test_redis.py

@@ -0,0 +1,93 @@
+""" test for app action functionality """
+from unittest.mock import patch
+
+from django.contrib.auth.models import Group
+from django.template.response import TemplateResponse
+from django.test import TestCase
+from django.test.client import RequestFactory
+
+from bookwyrm import models, views
+from bookwyrm.management.commands import initdb
+from bookwyrm.tests.validate_html import validate_html
+
+
+class RedisStatusViews(TestCase):
+    """every response to a get request, html or json"""
+
+    @classmethod
+    def setUpTestData(cls):
+        """we need basic test data and mocks"""
+        with (
+            patch("bookwyrm.suggested_users.rerank_suggestions_task.delay"),
+            patch("bookwyrm.activitystreams.populate_stream_task.delay"),
+            patch("bookwyrm.lists_stream.populate_lists_task.delay"),
+        ):
+            cls.local_user = models.User.objects.create_user(
+                "[email protected]",
+                "[email protected]",
+                "password",
+                local=True,
+                localname="mouse",
+            )
+        initdb.init_groups()
+        initdb.init_permissions()
+        group = Group.objects.get(name="admin")
+        cls.local_user.groups.set([group])
+        models.SiteSettings.objects.create()
+
+    def setUp(self):
+        """individual test setup"""
+        self.factory = RequestFactory()
+
+    def test_redis_status_get(self):
+        """there are so many views, this just makes sure it LOADS"""
+        view = views.RedisStatus.as_view()
+        request = self.factory.get("")
+        request.user = self.local_user
+
+        result = view(request)
+        self.assertIsInstance(result, TemplateResponse)
+        validate_html(result.render())
+        self.assertEqual(result.status_code, 200)
+
+    def test_redis_status_post_scan_keys(self):
+        """count keys in redis"""
+        view = views.RedisStatus.as_view()
+        request = self.factory.post("", {"dry_run": True})
+        request.user = self.local_user
+
+        result = view(request)
+        self.assertIsInstance(result, TemplateResponse)
+        validate_html(result.render())
+        self.assertEqual(result.status_code, 200)
+        self.assertTrue("outdated_identified" in result.context_data)
+        self.assertFalse("outdated_deleted" in result.context_data)
+        self.assertFalse("cache_deleted" in result.context_data)
+
+    def test_redis_status_post_erase_keys(self):
+        """count keys in redis"""
+        view = views.RedisStatus.as_view()
+        request = self.factory.post("")
+        request.user = self.local_user
+
+        result = view(request)
+        self.assertIsInstance(result, TemplateResponse)
+        validate_html(result.render())
+        self.assertEqual(result.status_code, 200)
+        self.assertFalse("outdated_identified" in result.context_data)
+        self.assertTrue("outdated_deleted" in result.context_data)
+        self.assertFalse("cache_deleted" in result.context_data)
+
+    def test_redis_status_post_erase_cache(self):
+        """count keys in redis"""
+        view = views.RedisStatus.as_view()
+        request = self.factory.post("", {"erase_cache": True})
+        request.user = self.local_user
+
+        result = view(request)
+        self.assertIsInstance(result, TemplateResponse)
+        validate_html(result.render())
+        self.assertEqual(result.status_code, 200)
+        self.assertFalse("outdated_identified" in result.context_data)
+        self.assertFalse("outdated_deleted" in result.context_data)
+        self.assertTrue("cache_deleted" in result.context_data)

bookwyrm/urls.py

@@ -369,6 +369,7 @@
     re_path(
         r"^settings/celery/ping/?$", views.celery_ping, name="settings-celery-ping"
     ),
+    re_path(r"^settings/redis/?$", views.RedisStatus.as_view(), name="settings-redis"),
     re_path(
         r"^settings/schedules/(?P<task_id>\d+)?$",
         views.ScheduledTasks.as_view(),

bookwyrm/views/__init__.py

@@ -5,6 +5,7 @@
 from .admin.automod import AutoMod, automod_delete, run_automod
 from .admin.automod import schedule_automod_task, unschedule_automod_task
 from .admin.celery_status import CeleryStatus, celery_ping
+from .admin.redis import RedisStatus
 from .admin.schedule import ScheduledTasks
 from .admin.dashboard import Dashboard
 from .admin.federation import Federation, FederatedServer

bookwyrm/views/admin/redis.py

@@ -0,0 +1,76 @@
+""" redis cache status """
+from django.contrib.auth.decorators import login_required, permission_required
+from django.template.response import TemplateResponse
+from django.utils.decorators import method_decorator
+from django.views import View
+import redis
+
+from bookwyrm import models, settings
+
+r = redis.from_url(settings.REDIS_ACTIVITY_URL)
+
+# pylint: disable= no-self-use
+@method_decorator(login_required, name="dispatch")
+@method_decorator(
+    permission_required("bookwyrm.edit_instance_settings", raise_exception=True),
+    name="dispatch",
+)
+class RedisStatus(View):
+    """Are your tasks running? Well you'd better go catch them"""
+
+    def get(self, request):
+        """See workers and active tasks"""
+        data = view_data()
+
+        return TemplateResponse(request, "settings/redis.html", data)
+
+    def post(self, request):
+        """Erase invalid keys"""
+        dry_run = request.POST.get("dry_run")
+        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:
+            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):
+    """Delete all redis activity keys according to a provided regex pattern"""
+    pipeline = r.pipeline()
+    key_count = 0
+    for key in r.scan_iter(match=pattern, count=count):
+        key_count += 1
+        if dry_run:
+            continue
+        pipeline.delete(key)
+    if not dry_run:
+        pipeline.execute()
+    return key_count