[TUTORIAL] Runtime Fields - Date Diff

runtime-example.txt

# Runtime Painless Example - Retrieve two date fields, diff them, then output a DDHHMMSS time. 
GET .ds-ilm-history-*/_search
{
  "fields": ["date.diff.create-step"],
  "runtime_mappings": {
    "date.diff.create-step": {
      "type": "keyword",
      "script": {
        "source": """
        ZonedDateTime step = ZonedDateTime.ofInstant(doc['state.step_time'].value.toInstant(), ZoneId.of('Z'));
        ZonedDateTime create = ZonedDateTime.ofInstant(doc['state.creation_date'].value.toInstant(), ZoneId.of('Z'));
        def days = ChronoUnit.DAYS.between(create, step);
        def hours = ChronoUnit.HOURS.between(create, step) % 24;
        def minutes = ChronoUnit.MINUTES.between(create, step) % (24*60);
        def seconds = ChronoUnit.SECONDS.between(create, step) % 60;
        emit(days + ' days ' + hours + ' hours ' + minutes + ' minutes ' + seconds + ' seconds')
        """
      }
    }
  }
}