Merge pull request #2385 from edx/derf/make_replset_name_overrideable

make replset name overrideable

playbooks/roles/mongo_3_0/defaults/main.yml

@@ -7,7 +7,7 @@ mongo_version: 3.0.6
 mongo_port: "27017"
 mongo_extra_conf: ''
 mongo_key_file: '/etc/mongodb_key'
-mongo_repl_set: rs0
+mongo_repl_set: "{{ MONGO_REPL_SET }}"
 mongo_cluster_members: []
 pymongo_version: 2.8.1
 
@@ -43,6 +43,7 @@ MONGO_USERS:
 
 MONGO_CLUSTERED: !!null
 MONGO_BIND_IP: 127.0.0.1
+MONGO_REPL_SET: "rs0"
 
 # Storage engine options in 3.0: "mmapv1" or "wiredTiger" 
 MONGO_STORAGE_ENGINE: "mmapv1"