Add option to set time key for elasticsearch (#7459)

Signed-off-by: Thomas Draebing <thomas.draebing@sap.com>

stable/fluent-bit/Chart.yaml

@@ -1,5 +1,5 @@
 name: fluent-bit
-version: 0.9.0
+version: 0.10.0
 appVersion: 0.13.0
 description: Fast and Lightweight Log/Data Forwarder for Linux, BSD and OSX
 keywords:

stable/fluent-bit/README.md

@@ -39,6 +39,7 @@ The following table lists the configurable parameters of the Fluent-Bit chart an
 | `backend.es.port`          | TCP port of the target Elasticsearch instance. | `9200` |
 | `backend.es.index`         | Elastic Index name | `kubernetes_cluster` |
 | `backend.es.type`          | Elastic Type name | `flb_type` |
+| `backend.es.time_key`          | Elastic Time Key | `@timestamp` |
 | `backend.es.logstash_prefix`  | Index Prefix. If Logstash_Prefix is equals to 'mydata' your index will become 'mydata-YYYY.MM.DD'. | `kubernetes_cluster` |
 | `backend.es.http_user`        | Optional username credential for Elastic X-Pack access. | `` |
 | `backend.es.http_passwd:`     | Password for user defined in HTTP_User. | `` |

stable/fluent-bit/templates/config.yaml

@@ -70,6 +70,9 @@ data:
         Logstash_Format On
         Retry_Limit False
         Type  {{ .Values.backend.es.type }}
+{{- if .Values.backend.es.time_key }}
+        Time_Key {{ .Values.backend.es.time_key }}
+{{- end }}
 {{ else if eq .Values.backend.type "splunk" }}
     [OUTPUT]
         Name  splunk

stable/fluent-bit/values.yaml

@@ -30,6 +30,7 @@ backend:
     index: kubernetes_cluster
     type: flb_type
     logstash_prefix: kubernetes_cluster
+    time_key: "@timestamp"
     # Optional username credential for Elastic X-Pack access
     http_user:
     # Password for user defined in HTTP_User