Switch result backend to redis

The AMQP result backend proved as impractical, this commit switches to
redis instead. The redis server is setup on the webinterface host but
can be configured on another host.

gnuviechadmin/gnuviechadmin/settings/base.py

@@ -349,8 +349,7 @@ WSGI_APPLICATION = '%s.wsgi.application' % SITE_NAME
 
 # ######### CELERY CONFIGURATION
 BROKER_URL = get_env_variable('GVA_BROKER_URL')
-CELERY_RESULT_BACKEND = 'amqp'
-CELERY_RESULT_PERSISTENT = True
+CELERY_RESULT_BACKEND = get_env_variable('GVA_RESULTS_REDIS_URL')
 CELERY_TASK_RESULT_EXPIRES = None
 CELERY_ROUTES = (
     'gvacommon.celeryrouters.GvaRouter',

requirements/base.txt

@@ -19,3 +19,4 @@ requests==2.9.1
 requests-oauthlib==0.6.0
 simplejson==3.8.1
 -e git+https://git.gnuviech-server.de/gvacommon.git@0.2.1#egg=gvacommon
+redis==2.10.5

salt/bootstrap.sh

@@ -27,6 +27,7 @@ EOF
 
 cat >/etc/salt/grains <<EOF
 roles:
+  - redis-server
   - rabbitmq-server
   - gnuviechadmin.database
   - gnuviechadmin.queues