Use the same Erlang cookie to enable clustering

Refs #243

data_bags/credentials/ejabberd.json

@@ -27,5 +27,12 @@
     "auth_tag": "yWRLb22JwJjjoK6Wdr1ujg==\n",
     "version": 3,
     "cipher": "aes-256-gcm"
+  },
+  "erlang_cookie": {
+    "encrypted_data": "UDCzEWgVLH0z33Exx5G+OjUXw1odz4xO8qRLXODo5jBzMQdyYQCd\n",
+    "iv": "mm+fYYceD1nPsuo1\n",
+    "auth_tag": "77un6mkgrHAmnBQhrhpPfQ==\n",
+    "version": 3,
+    "cipher": "aes-256-gcm"
   }
 }

site-cookbooks/kosmos-ejabberd/recipes/default.rb

@@ -43,6 +43,13 @@ dpkg_package "ejabberd" do
   notifies :create, "file[/lib/systemd/system/ejabberd.service]", :immediately
 end
 
+file "/opt/ejabberd/.erlang.cookie" do
+  mode "0400"
+  owner "ejabberd"
+  group "ejabberd"
+  content ejabberd_credentials['erlang_cookie']
+end
+
 postgresql_data_bag_item = data_bag_item('credentials', 'postgresql')
 
 hosts = [