feat: add heap_size_limit field for input.kibana (#10243)

plugins/inputs/kibana/README.md

@@ -42,6 +42,7 @@ The `kibana` plugin queries the [Kibana][] API to obtain the service status.
     - heap_total_bytes (integer)
     - heap_max_bytes (integer; deprecated in 1.13.3: use `heap_total_bytes` field)
     - heap_used_bytes (integer)
+    - heap_size_limit (integer)
     - uptime_ms (integer)
     - response_time_avg_ms (float)
     - response_time_max_ms (integer)

plugins/inputs/kibana/kibana.go

@@ -77,6 +77,7 @@ type memory struct {
 type heap struct {
 	TotalInBytes int64 `json:"total_in_bytes"`
 	UsedInBytes  int64 `json:"used_in_bytes"`
+	SizeLimit    int64 `json:"size_limit"`
 }
 
 const sampleConfig = `
@@ -222,6 +223,7 @@ func (k *Kibana) gatherKibanaStatus(baseURL string, acc telegraf.Accumulator) er
 		fields["heap_max_bytes"] = kibanaStatus.Metrics.Process.Memory.Heap.TotalInBytes
 		fields["heap_total_bytes"] = kibanaStatus.Metrics.Process.Memory.Heap.TotalInBytes
 		fields["heap_used_bytes"] = kibanaStatus.Metrics.Process.Memory.Heap.UsedInBytes
+		fields["heap_size_limit"] = kibanaStatus.Metrics.Process.Memory.Heap.SizeLimit
 	} else {
 		fields["uptime_ms"] = int64(kibanaStatus.Metrics.UptimeInMillis)
 		fields["heap_max_bytes"] = kibanaStatus.Metrics.Process.Mem.HeapMaxInBytes

plugins/inputs/kibana/testdata_test6_5.go

@@ -219,6 +219,7 @@ var kibanaStatusExpected6_5 = map[string]interface{}{
 	"heap_total_bytes":       int64(149954560),
 	"heap_max_bytes":         int64(149954560),
 	"heap_used_bytes":        int64(126274392),
+	"heap_size_limit":        int64(1501560832),
 	"uptime_ms":              int64(2173595337),
 	"response_time_avg_ms":   float64(12.5),
 	"response_time_max_ms":   int64(123),