How to make elasticsearch add the timestamp field to every document in all indices?

Question

Elasticsearch experts,

I have been unable to find a simple way to just tell ElasticSearch to insert the _timestamp field for all the documents that are added in all

Answer 1

Elasticsearch used to support automatically adding timestamps to documents being indexed, but deprecated this feature in 2.0.0

From the version 5.5 documentation:

The _timestamp and _ttl fields were deprecated and are now removed. As a replacement for _timestamp, you should populate a regular date field with the current timestamp on application side.