[RFC 1/4] Automatically remove old events

[Stephen Finucane]

Events are created for most state changes in Patchwork which means
they're fairly numerous. Start removing them after a (configurable)
interval.

Signed-off-by: Stephen Finucane <stephen at that.guru>
---
 docs/deployment/configuration.rst                      |  7 +++++++
 docs/usage/overview.rst                                |  2 ++
 patchwork/management/commands/cron.py                  |  2 ++
 patchwork/notifications.py                             | 18 ++++++++++++++----
 patchwork/settings/base.py                             |  3 +++
 ...tomatically-remove-old-events-4ee222aaf4a6ea6c.yaml |  8 ++++++++
 6 files changed, 36 insertions(+), 4 deletions(-)
 create mode 100644 releasenotes/notes/automatically-remove-old-events-4ee222aaf4a6ea6c.yaml

diff --git a/docs/deployment/configuration.rst b/docs/deployment/configuration.rst
index 34748563..3494bd39 100644
--- a/docs/deployment/configuration.rst
+++ b/docs/deployment/configuration.rst
@@ -51,6 +51,13 @@ This is customizable on a per-user basis from the user configuration page.
     This option was previously named ``DEFAULT_PATCHES_PER_PAGE``. It was
     renamed as cover letters are now supported also.
 
+``EVENT_VALIDITY_DAYS``
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The number of days to retain :ref:`events` for. After this interval, the
+:ref:`cron management command <deployment-final-steps>` will delete the
+request.
+
 ``CONFIRMATION_VALIDITY_DAYS``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/docs/usage/overview.rst b/docs/usage/overview.rst
index 802de2f1..7ac265f7 100644
--- a/docs/usage/overview.rst
+++ b/docs/usage/overview.rst
@@ -207,6 +207,8 @@ To-do Lists
 
 Patchwork users can store a to-do list of patches.
 
+.. _events:
+
 Events
 ------
 
diff --git a/patchwork/management/commands/cron.py b/patchwork/management/commands/cron.py
index 2be234b1..653fb0b3 100644
--- a/patchwork/management/commands/cron.py
+++ b/patchwork/management/commands/cron.py
@@ -19,6 +19,7 @@
 
 from django.core.management.base import BaseCommand
 
+from patchwork.notifications import expire_events
 from patchwork.notifications import expire_notifications
 from patchwork.notifications import send_notifications
 
@@ -34,3 +35,4 @@ class Command(BaseCommand):
                               (recipient.email, error))
 
         expire_notifications()
+        expire_events()
diff --git a/patchwork/notifications.py b/patchwork/notifications.py
index 88e96628..b604d579 100644
--- a/patchwork/notifications.py
+++ b/patchwork/notifications.py
@@ -1,5 +1,6 @@
 # Patchwork - automated patch tracking system
 # Copyright (C) 2008 Jeremy Kerr <jk at ozlabs.org>
+# Copyright (C) 2017 Stephen Finucane <stephen at that.guru>
 #
 # This file is part of the Patchwork package.
 #
@@ -31,6 +32,7 @@ from django.template.loader import render_to_string
 
 from patchwork.models import EmailConfirmation
 from patchwork.models import EmailOptout
+from patchwork.models import Event
 from patchwork.models import PatchChangeNotification
 
 
@@ -109,8 +111,16 @@ def expire_notifications():
     EmailConfirmation.objects.filter(q).delete()
 
     # remove inactive users with no pending confirmation
-    pending_confs = EmailConfirmation.objects.values('user')
-    users = User.objects.filter(is_active=False).exclude(id__in=pending_confs)
+    pending_conf = EmailConfirmation.objects.values('user')
+    User.objects.filter(is_active=False).exclude(id__in=pending_conf).delete()
 
-    # delete users
-    users.delete()
+
+def expire_events():
+    """Drop excess events.
+
+    Events are generated for almost everything and shouldn't be allowed
+    to grow unchecked. This task cleans them up.
+    """
+    event_validity = datetime.timedelta(days=settings.EVENTS_VALIDITY_DAYS)
+    q = Q(date__lt=datetime.datetime.now() - event_validity)
+    Event.objects.filter(q).delete()
diff --git a/patchwork/settings/base.py b/patchwork/settings/base.py
index 4b0d5513..30734ece 100644
--- a/patchwork/settings/base.py
+++ b/patchwork/settings/base.py
@@ -204,9 +204,12 @@ LOGGING = {
 #
 # Patchwork settings
 #
+# https://patchwork.readthedocs.io/en/latest/deployment/configuration/
 
 DEFAULT_ITEMS_PER_PAGE = 100
 
+EVENTS_VALIDITY_DAYS = 14
+
 CONFIRMATION_VALIDITY_DAYS = 7
 
 NOTIFICATION_DELAY_MINUTES = 10
diff --git a/releasenotes/notes/automatically-remove-old-events-4ee222aaf4a6ea6c.yaml b/releasenotes/notes/automatically-remove-old-events-4ee222aaf4a6ea6c.yaml
new file mode 100644
index 00000000..92590e49
--- /dev/null
+++ b/releasenotes/notes/automatically-remove-old-events-4ee222aaf4a6ea6c.yaml
@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    The ``EVENTS_VALIDITY_DAYS`` configuration option is added. This configures
+    the number of days that an event should be retained for.
+  - |
+    The ``cron`` management command will now remove events older than
+    ``EVENTS_VALIDITY_DAYS`` days.
-- 
2.14.3