Fixed #73 -- Add memcached configuration options

deployment/docker/standalone/Dockerfile

@@ -3,7 +3,7 @@ FROM debian:jessie
 RUN apt-get update && apt-get install -y supervisor python3 git python3-pip \
 	libxml2-dev libxslt1-dev python-dev python-virtualenv locales libffi-dev \
 	build-essential python3-dev zlib1g-dev libssl-dev npm gettext git \
-	libpq-dev libmysqlclient-dev \ 
+	libpq-dev libmysqlclient-dev libmemcached-dev \
 	--no-install-recommends
 
 WORKDIR /
@@ -27,6 +27,7 @@ WORKDIR /pretix/src
 RUN pip3 install -r requirements.txt
 RUN pip3 install -r requirements/mysql.txt
 RUN pip3 install -r requirements/postgres.txt
+RUN pip3 install -r requirements/memcached.txt
 RUN pip3 install gunicorn
 
 RUN make

doc/admin/config.rst

@@ -93,7 +93,7 @@ Example::
     Connection details for the database connection. Empty by default.
 
 URLs
------
+----
 
 Example::
 
@@ -161,4 +161,17 @@ Example::
     .. WARNING:: Never set this to ``True`` in production!
 
 
+Memcached
+---------
+
+You can use an existing memcached server as pretix's caching backend::
+
+    [memcached]
+    location=127.0.0.1:11211
+
+``location``
+    The location of memcached, either a host:port combination or a socket file.
+
+If no memcached is configures, pretix will use Django's built-in local-memory caching method.
+
 .. _Python documentation: https://docs.python.org/3/library/configparser.html?highlight=configparser#supported-ini-file-structure

src/pretix/settings.py

@@ -74,6 +74,14 @@ SESSION_COOKIE_SECURE = SESSION_COOKIE_HTTPONLY = config.getboolean(
 LANGUAGE_COOKIE_DOMAIN = SESSION_COOKIE_DOMAIN = CSRF_COOKIE_DOMAIN = config.get(
     'pretix', 'cookiedomain', fallback=None)
 
+if config.has_option('memcached', 'location'):
+    CACHES = {
+        'default': {
+            'BACKEND': 'django.core.cache.backends.memcached.PyLibMCCache',
+            'LOCATION': config.get('memcached', 'location'),
+        }
+    }
+
 # Internal settings
 
 STATIC_ROOT = '_static'

src/requirements/memcached.txt

@@ -0,0 +1 @@
+pylibmc