Add drop for sensitive and incompatible fields

Nested timestamp in openstack context contains data with
incompatible for elasticsearch format.

Drop all token related fields

Change-Id: If3b228a7d1f0cab5446bc08f4b3838b9b03b738f
diff --git a/fluentd/label/default_output/elasticsearch.yml b/fluentd/label/default_output/elasticsearch.yml
index 3c26d15..84b2dc1 100644
--- a/fluentd/label/default_output/elasticsearch.yml
+++ b/fluentd/label/default_output/elasticsearch.yml
@@ -9,6 +9,19 @@
       config:
         label:
           default_output:
+            filter:
+              drop_nested_timestamp_and_sensitive_data:
+                tag: "openstack.**"
+                type: record_transformer
+                enable_ruby: true
+                remove_keys: '["_dummy_1", "_dummy_2", "_dummy_3"]'
+                record:
+                  - name: _dummy_1
+                    value: ${fluentd:dollar}{if record.has_key?("context"); record["context"].delete("timestamp") ; end; nil }
+                  - name: _dummy_2
+                    value: ${fluentd:dollar}{if record.has_key?("context"); record["context"].delete("auth_token"); end; nil}
+                  - name: _dummy_3
+                    value: ${fluentd:dollar}{if record.has_key?("context"); record["context"].delete("auth_token_info"); end; nil}
             match:
               elasticsearch_output:
                 host: ${_param:fluentd_elasticsearch_host}