Prometheus API

Data Structures
struct	prometheus_collector
	Prometheus collector definition. More...
struct	prometheus_counter
	Type used to represent a Prometheus counter metric. More...
struct	prometheus_gauge
	Type used to represent a Prometheus gauge metric. More...
struct	prometheus_histogram_bucket
	Prometheus histogram bucket definition. More...
struct	prometheus_histogram
	Type used to represent a Prometheus histogram metric. More...
struct	prometheus_label
	Prometheus label definition. More...
struct	prometheus_metric
	Type used to represent a Prometheus metric base. More...
struct	prometheus_summary_quantile
	Prometheus summary quantile definition. More...
struct	prometheus_summary
	Type used to represent a Prometheus summary metric. More...

Macros
#define	PROMETHEUS_COLLECTOR_DEFINE(_name)
	Prometheus Collector definition.
#define	PROMETHEUS_COUNTER_DEFINE(_name, _detail)
	Prometheus Counter definition.
#define	PROMETHEUS_GAUGE_DEFINE(_name, _detail)
	Prometheus Gauge definition.
#define	PROMETHEUS_HISTOGRAM_DEFINE(_name, _detail)
	Prometheus Histogram definition.
#define	MAX_PROMETHEUS_LABEL_KEY_LENGTH   16
#define	MAX_PROMETHEUS_LABEL_VALUE_LENGTH   16
#define	MAX_PROMETHEUS_LABELS_PER_METRIC   5
#define	MAX_METRIC_NAME_LENGTH   32
#define	MAX_METRIC_DESCRIPTION_LENGTH   64
#define	PROMETHEUS_SUMMARY_DEFINE(_name, _detail)
	Prometheus Summary definition.

Enumerations
enum	prometheus_metric_type { PROMETHEUS_COUNTER = 0 , PROMETHEUS_GAUGE , PROMETHEUS_SUMMARY , PROMETHEUS_HISTOGRAM }
	Prometheus metric types. More...

Functions
int	prometheus_collector_register_metric (struct prometheus_collector *collector, struct prometheus_metric *metric)
	Register a metric with a Prometheus collector.
const void *	prometheus_collector_get_metric (const struct prometheus_collector *collector, const char *name)
	Get a metric from a Prometheus collector.
int	prometheus_counter_inc (struct prometheus_counter *counter)
	Increment the value of a Prometheus counter metric Increments the value of the specified counter metric by one.
int	prometheus_format_exposition (const struct prometheus_collector *collector, char *buffer, size_t buffer_size)
	Format exposition data for Prometheus.
int	prometheus_gauge_set (struct prometheus_gauge *gauge, double value)
	Set the value of a Prometheus gauge metric.
int	prometheus_histogram_observe (struct prometheus_histogram *histogram, double value)
	Observe a value in a Prometheus histogram metric.
int	prometheus_summary_observe (struct prometheus_summary *summary, double value)
	Observes a value in a Prometheus summary metric.

Detailed Description

Since

4.0

Version

0.1.0

Macro Definition Documentation

MAX_METRIC_DESCRIPTION_LENGTH

#define MAX_METRIC_DESCRIPTION_LENGTH   64

#include <zephyr/net/prometheus/metric.h>

MAX_METRIC_NAME_LENGTH

#define MAX_METRIC_NAME_LENGTH   32

#include <zephyr/net/prometheus/metric.h>

MAX_PROMETHEUS_LABEL_KEY_LENGTH

#define MAX_PROMETHEUS_LABEL_KEY_LENGTH   16

#include <zephyr/net/prometheus/label.h>

MAX_PROMETHEUS_LABEL_VALUE_LENGTH

#define MAX_PROMETHEUS_LABEL_VALUE_LENGTH   16

#include <zephyr/net/prometheus/label.h>

MAX_PROMETHEUS_LABELS_PER_METRIC

#define MAX_PROMETHEUS_LABELS_PER_METRIC   5

#include <zephyr/net/prometheus/label.h>

PROMETHEUS_COLLECTOR_DEFINE

#define PROMETHEUS_COLLECTOR_DEFINE

(

_name

)

#include <zephyr/net/prometheus/collector.h>

Value:

        static STRUCT_SECTION_ITERABLE(prometheus_collector, _name) = {                            \
                .name = STRINGIFY(_name), .size = 0, .metric = {0}}

Prometheus Collector definition.

This macro defines a Collector.

Parameters

_name

The collector's name.

PROMETHEUS_COUNTER_DEFINE

#define PROMETHEUS_COUNTER_DEFINE	(		_name,
			_detail )

#include <zephyr/net/prometheus/counter.h>

Value:

        static STRUCT_SECTION_ITERABLE(prometheus_counter, _name) = {.base = (void *)(_detail),    \
                                                                     .value = 0}

Prometheus Counter definition.

This macro defines a Counter metric.

Parameters

_name	The channel's name.
_detail	The metric base.

Example usage:

 struct prometheus_metric http_request_counter = {
        .type = PROMETHEUS_COUNTER,
        .name = "http_request_counter",
        .description = "HTTP request counter",
        .num_labels = 1,
        .labels = {
                { .key = "http_request", .value = "request_count",}
        },
};
 
 PROMETHEUS_COUNTER_DEFINE(test_counter, &test_counter_metric);

PROMETHEUS_GAUGE_DEFINE

#define PROMETHEUS_GAUGE_DEFINE	(		_name,
			_detail )

#include <zephyr/net/prometheus/gauge.h>

Value:

        static STRUCT_SECTION_ITERABLE(prometheus_gauge, _name) = {.base = (void *)(_detail),      \
                                                                   .value = 0}

Prometheus Gauge definition.

This macro defines a Gauge metric.

Parameters

_name	The channel's name.
_detail	The metric base.

Example usage:

struct prometheus_metric http_request_gauge = {
     .type = PROMETHEUS_GAUGE,
     .name = "http_request_gauge",
     .description = "HTTP request gauge",
     .num_labels = 1,
     .labels = {
        { .key = "http_request", .value = "request_count",}
     },
};
 
PROMETHEUS_GAUGE_DEFINE(test_gauge, &test_gauge_metric);

PROMETHEUS_HISTOGRAM_DEFINE

#define PROMETHEUS_HISTOGRAM_DEFINE	(		_name,
			_detail )

#include <zephyr/net/prometheus/histogram.h>

Value:

        static STRUCT_SECTION_ITERABLE(prometheus_histogram, _name) = {.base = (void *)(_detail),  \
                                                                       .buckets = NULL,            \
                                                                       .num_buckets = 0,           \
                                                                       .sum = 0,                   \
                                                                       .count = 0}

Prometheus Histogram definition.

This macro defines a Histogram metric.

Parameters

_name	The channel's name.
_detail	The metric base.

Example usage:

struct prometheus_metric http_request_gauge = {
     .type = PROMETHEUS_HISTOGRAM,
     .name = "http_request_histograms",
     .description = "HTTP request histogram",
     .num_labels = 1,
     .labels = {
        { .key = "request_latency", .value = "request_latency_seconds",}
     },
};
 
PROMETHEUS_HISTOGRAM_DEFINE(test_histogram, &test_histogram_metric);

PROMETHEUS_SUMMARY_DEFINE

#define PROMETHEUS_SUMMARY_DEFINE	(		_name,
			_detail )

#include <zephyr/net/prometheus/summary.h>

Value:

        static STRUCT_SECTION_ITERABLE(prometheus_summary, _name) = {.base = (void *)(_detail),    \
                                                                     .quantiles = NULL,            \
                                                                     .num_quantiles = 0,           \
                                                                     .sum = 0,                     \
                                                                     .count = 0}

Prometheus Summary definition.

This macro defines a Summary metric.

Parameters

_name	The channel's name.
_detail	The metric base.

Example usage:

struct prometheus_metric http_request_gauge = {
     .type = PROMETHEUS_SUMMARY,
     .name = "http_request_summary",
     .description = "HTTP request summary",
     .num_labels = 1,
     .labels = {
        { .key = "request_latency", .value = "request_latency_seconds",}
     },
};
 
PROMETHEUS_SUMMARY_DEFINE(test_summary, &test_summary_metric);

Enumeration Type Documentation

prometheus_metric_type

enum prometheus_metric_type

#include <zephyr/net/prometheus/metric.h>

Prometheus metric types.

• References
• See https://prometheus.io/docs/concepts/metric_types

Enumerator
PROMETHEUS_COUNTER	Prometheus Counter.
PROMETHEUS_GAUGE	Prometheus Gauge.
PROMETHEUS_SUMMARY	Prometheus Summary.
PROMETHEUS_HISTOGRAM	Prometheus Histogram.

Function Documentation

prometheus_collector_get_metric()

const void * prometheus_collector_get_metric	(	const struct prometheus_collector *	collector,
		const char *	name )

#include <zephyr/net/prometheus/collector.h>

Get a metric from a Prometheus collector.

Retrieves the metric with the specified name from the given collector.

Parameters

collector	Pointer to the collector to retrieve the metric from.
name	Name of the metric to retrieve.

Returns

Pointer to the retrieved metric, or NULL if not found.

prometheus_collector_register_metric()

int prometheus_collector_register_metric	(	struct prometheus_collector *	collector,
		struct prometheus_metric *	metric )

#include <zephyr/net/prometheus/collector.h>

Register a metric with a Prometheus collector.

Registers the specified metric with the given collector.

Parameters

collector	Pointer to the collector to register the metric with.
metric	Pointer to the metric to register.

Returns

0 if successful, otherwise a negative error code.

Return values

-EINVAL	Invalid arguments.
-ENOMEM	Not enough memory to register the metric.

prometheus_counter_inc()

int prometheus_counter_inc

(

struct prometheus_counter *

counter

)

#include <zephyr/net/prometheus/counter.h>

Increment the value of a Prometheus counter metric Increments the value of the specified counter metric by one.

Parameters

counter

Pointer to the counter metric to increment.

Returns

0 on success, negative errno on error.

prometheus_format_exposition()

int prometheus_format_exposition	(	const struct prometheus_collector *	collector,
		char *	buffer,
		size_t	buffer_size )

#include <zephyr/net/prometheus/formatter.h>

Format exposition data for Prometheus.

Formats the exposition data collected by the specified collector into the provided buffer. Function to format metric data according to Prometheus text-based format

Parameters

collector	Pointer to the collector containing the data to format.
buffer	Pointer to the buffer where the formatted exposition data will be stored.
buffer_size	Size of the buffer.

Returns

0 on success, negative errno on error.

prometheus_gauge_set()

int prometheus_gauge_set	(	struct prometheus_gauge *	gauge,
		double	value )

#include <zephyr/net/prometheus/gauge.h>

Set the value of a Prometheus gauge metric.

Sets the value of the specified gauge metric to the given value.

Parameters

gauge	Pointer to the gauge metric to set.
value	Value to set the gauge metric to.

Returns

0 on success, -EINVAL if the value is negative.

prometheus_histogram_observe()

int prometheus_histogram_observe	(	struct prometheus_histogram *	histogram,
		double	value )

#include <zephyr/net/prometheus/histogram.h>

Observe a value in a Prometheus histogram metric.

Observes the specified value in the given histogram metric.

Parameters

histogram	Pointer to the histogram metric to observe.
value	Value to observe in the histogram metric.

Returns

0 on success, -EINVAL if the value is negative.

prometheus_summary_observe()

int prometheus_summary_observe	(	struct prometheus_summary *	summary,
		double	value )

#include <zephyr/net/prometheus/summary.h>

Observes a value in a Prometheus summary metric.

Observes the specified value in the given summary metric.

Parameters

summary	Pointer to the summary metric to observe.
value	Value to observe in the summary metric.

Returns

0 on success, -EINVAL if the value is negative.