net: prometheus: Configure max number of labels from Kconfig

Allow user to configure the label count from Kconfig.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

include/zephyr/net/prometheus/label.h

@@ -16,8 +16,12 @@
  * @{
  */
 
-/* maximum namber of labels per metric */
-#define MAX_PROMETHEUS_LABELS_PER_METRIC  5
+#if defined(CONFIG_PROMETHEUS)
+/** Maximum number of labels per metric */
+#define MAX_PROMETHEUS_LABELS_PER_METRIC CONFIG_PROMETHEUS_LABEL_MAX_COUNT
+#else
+#define MAX_PROMETHEUS_LABELS_PER_METRIC 1
+#endif /* CONFIG_PROMETHEUS */
 
 /**
  * @brief Prometheus label definition.

subsys/net/lib/prometheus/Kconfig

@@ -10,6 +10,13 @@ menuconfig PROMETHEUS
 
 if PROMETHEUS
 
+config PROMETHEUS_LABEL_MAX_COUNT
+	int "Max label count in metric"
+	range 1 8
+	default 1
+	help
+	  Specify how many labels can be attached to a metric.
+
 module = PROMETHEUS
 module-dep = NET_LOG
 module-str = Log level for PROMETHEUS