Implement basic varnish purging

This allows all models inherited from PgModel to specify which
URLs to purge by either setting a field or defining a function
called purge_urls, at which point they will be purged whenever
the save signal is fired.

Also implements a form under /admin/purge/ that allows for manual
purging. This should probably be extended in the future to show
the status of the pgq slaves, but that will come later.

Includes a SQL function that posts the expires to a pgq queue. For
a local deployment, this can be replaced with a simple void function
to turn off varnish purging.

1 files changed, 9 insertions, 0 deletions

diff --git a/pgweb/docs/models.py b/pgweb/docs/models.py
index 931d868a..7295c69c 100644
--- a/pgweb/docs/models.py
+++ b/pgweb/docs/models.py
@@ -1,6 +1,7 @@
 from django.db import models
 from django.contrib.auth.models import User
 from pgweb.util.bases import PgModel
+from pgweb.core.models import Version
 
 from datetime import datetime
 
@@ -24,6 +25,14 @@ class DocComment(PgModel, models.Model):
 
 	send_notification = True
 
+	def purge_urls(self):
+		yield '/docs/%s/interactive/%s' % (self.version, self.file)
+		try:
+			if Version.objects.get(tree=self.version).current:
+				yield '/docs/current/interactive/%s' % self.file
+		except Version.DoesNotExist:
+			pass
+
 	class Meta:
 		ordering = ('-posted_at',)