prometheus_callback Struct Reference

Defines a callback that will be invoked when the HTTP route is called. More...

#include <res_prometheus.h>

Data Fields
void(*	callback_fn )(struct ast_str **output)
	The callback function to invoke. More...
const char *	name
	The name of our callback (always useful for debugging) More...

Detailed Description

Defines a callback that will be invoked when the HTTP route is called.

This callback presents the second way of passing metrics to a Prometheus server. For metrics that are generated often or whose value needs to be stored, metrics can be created and registered. For metrics that can be obtained "on-the-fly", this mechanism is preferred. When the HTTP route is queried by prometheus, the registered callbacks are invoked. The string passed to the callback should be populated with stack-allocated metrics using prometheus_metric_to_string.

Example Usage:

static void prometheus_metric_callback(struct ast_str **output)
{
   struct prometheus_metric test_counter =
       PROMETHEUS_METRIC_STATIC_INITIALIZATION(
           PROMETHEUS_METRIC_COUNTER,
           "test_counter",
           "A test counter",
           NULL);
 
   prometheus_metric_to_string(&test_counter, output);
}
 
static void load_module(void)
{
   struct prometheus_callback callback = {
       .name = "test_callback",
       .callback_fn = &prometheus_metric_callback,
   };
 
   prometheus_callback_register(&callback);
}

Definition at line 404 of file res_prometheus.h.

Field Documentation

callback_fn

void(* callback_fn) (struct ast_str **output)

The callback function to invoke.

Definition at line 412 of file res_prometheus.h.

Referenced by prometheus_callback_register(), and scrape_metrics().

name

const char* name

The name of our callback (always useful for debugging)

Definition at line 408 of file res_prometheus.h.

Referenced by AST_TEST_DEFINE(), PathSegment::get_child(), Parameter::load(), Property::load(), SwaggerType::load(), prometheus_callback_register(), and prometheus_callback_unregister().

---

The documentation for this struct was generated from the following file:

• res_prometheus.h