Make the varnish queue id configurable

This is required if the queue is dropped and recreated in pgq as it
gets a new id, which needs to be used when viewing the current status
of the queue in the admin interface.

pgweb/core/views.py

@@ -206,7 +206,7 @@ def admin_purge(request):
 
 	# Fetch list of latest purges
 	curs = connection.cursor()
-	curs.execute("SELECT ev_time, ev_type, ev_data FROM pgq.event_1 WHERE ev_type IN ('P', 'X') ORDER BY ev_time DESC LIMIT 20")
+	curs.execute("SELECT ev_time, ev_type, ev_data FROM pgq.event_%s WHERE ev_type IN ('P', 'X') ORDER BY ev_time DESC LIMIT 20" % settings.VARNISH_QUEUE_ID)
 	latest = [{'t': r[0], 'ty': r[1], 'u': r[2]} for r in curs.fetchall()]
 
 	return render_to_response('core/admin_purge.html', {

pgweb/settings.py

@@ -156,6 +156,7 @@
 FTP_MASTERS=()										   # A tuple containing the *IP addresses* of all machines
                                                        # trusted to upload ftp structure data
 VARNISH_PURGERS=()                                     # Extra servers that can do varnish purges through our queue
+VARNISH_QUEUE_ID=1									   # pgq queue id used for varnish purging
 ARCHIVES_SEARCH_SERVER="archives.postgresql.org"       # Where to post REST request for archives search
 
 # Load local settings overrides