A Kibana dev console POST to API /_flush failed because the needed header was not included (-H 'X-elastic-product-origin: kibana') - should we always include this?

[EricDavisX]

tested on version 8.0 circa early June.

This came up out of a discussion based on a Fleet Server issue, here:
elastic/fleet-server#426

I was trying to POST /_flush in the console and got this 400 error resp:

{
  "error" : {
    "root_cause" : [
      {
        "type" : "illegal_argument_exception",
        "reason" : "Data stream(s) [.fleet-actions-results] use and access is reserved for system operations"
      }
    ],
    "type" : "illegal_argument_exception",
    "reason" : "Data stream(s) [.fleet-actions-results] use and access is reserved for system operations"
  },
  "status" : 400
}

The team helped identify that the call would work if we included the below header in the request:
X-elastic-product-origin: kibana

Is there a reason not to do this (always) from the dev console?

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)

[mshustov]

yes, it's done intentionally to prevent direct access to system indices #90123 as it defeats the purpose of system indices.

[EricDavisX]

thanks so much - I'll close this out then!