logging configure fluent to merge_json_log

roles/openshift_logging_fluentd/defaults/main.yml

@@ -27,6 +27,10 @@ openshift_logging_fluentd_app_port: 9200
 openshift_logging_fluentd_ops_host: "{{ openshift_logging_fluentd_app_host }}"
 openshift_logging_fluentd_ops_port: "{{ openshift_logging_fluentd_app_port }}"
 
+# openshift_logging_fluentd_merge_json_log configures fluentd to parse
+# JSON log messages into the top level payload envelope
+openshift_logging_fluentd_merge_json_log: "true"
+
 ### Used by "hosted" and "secure-aggregator" deployments
 openshift_logging_fluentd_journal_source: "{{ openshift_hosted_logging_journal_source | default('') }}"
 openshift_logging_fluentd_journal_read_from_head: "{{ openshift_hosted_logging_journal_read_from_head | default('') }}"

roles/openshift_logging_fluentd/templates/fluentd.j2

@@ -96,6 +96,8 @@ spec:
           readOnly: true
 {% endif %}
         env:
+        - name: "MERGE_JSON_LOG"
+          value: "{{ openshift_logging_fluentd_merge_json_log }}"
         - name: "K8S_HOST_URL"
           value: "{{ openshift_logging_fluentd_master_url }}"
         - name: "ES_HOST"