Detect empty array

Elastic Stack Logstash
1

Hi,

how could I detect when an array in a json is empty with logstash ?

example:

  • EMPTY

      "serviceContexts": [
	]

  • FULL:

    "serviceContexts": [{
  		"service": "JIRA",
  		"monitor": true,
  		"client": null,
  		"org": null,
  		"app": null,
  		"method": "KeyGet",
  		"status": "failure",
  		"duration": 1
  	}
  ]
2 
if [serviceContexts] and [serviceContexts][0] {
  # array has at least one element
} else {
  # array has no elements
}
3

Yes this is what I come up with. Wasn't sure if that was the best way to do it.

Thanks