Add support for redis to Zaqar's lib

A new redis driver has landed in Zaqar. This patch adds support for that
driver to Zaqar's lib.

Change-Id: I97629a303c55ee098e3bfbc534bfb05ccab94649

files/apts/zaqar-server

@@ -1,3 +1,5 @@
 python-pymongo
 mongodb-server
 pkg-config
+redis-server # NOPRIME
+python-redis # NOPRIME

files/rpms/zaqar-server

@@ -1,3 +1,5 @@
 selinux-policy-targeted
 mongodb-server
 pymongo
+redis # NOPRIME
+python-redis # NOPRIME

lib/zaqar

@@ -125,11 +125,27 @@ function configure_zaqar {
         iniset $ZAQAR_CONF  drivers storage mongodb
         iniset $ZAQAR_CONF 'drivers:storage:mongodb' uri mongodb://localhost:27017/zaqar
         configure_mongodb
+    elif [ "$ZAQAR_BACKEND" = 'redis' ] ; then
+        iniset $ZAQAR_CONF  drivers storage redis
+        iniset $ZAQAR_CONF 'drivers:storage:redis' uri redis://localhost:6379
+        configure_redis
     fi
 
     cleanup_zaqar
 }
 
+function configure_redis {
+    if is_ubuntu; then
+        install_package redis-server
+    elif is_fedora; then
+        install_package redis
+    else
+        exit_distro_not_supported "redis installation"
+    fi
+
+    install_package python-redis
+}
+
 function configure_mongodb {
     # Set nssize to 2GB. This increases the number of namespaces supported
     # # per database.