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net: prometheus: Add more parameters to metric macros

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Add collector parameter to metric creation macros so that it
is possible to bind the metric to collector already at built
time.

Also add optional user_data to metric macro calls so that user
can add optional data there. This will be used by network statistics
Prometheus support in subsequent commits.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>
This commit is contained in:
Jukka Rissanen 2024-11-20 18:31:22 +02:00 • committed by Anas Nashif
commit c7989b5747
13 changed files with 117 additions and 17 deletions
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37
include/zephyr/net/prometheus/collector.h
View file

@ -26,6 +26,22 @@
#include <stddef.h>
struct prometheus_collector;
/**
* @typedef prometheus_scrape_cb_t
* @brief Callback used to scrape a collector for a specific metric.
*
* @param collector A valid pointer on the collector to scrape
* @param metric A valid pointer on the metric to scrape
* @param user_data A valid pointer to a user data or NULL
*
* @return 0 if successful, otherwise a negative error code.
*/
typedef int (*prometheus_scrape_cb_t)(struct prometheus_collector *collector,
struct prometheus_metric *metric,
void *user_data);
/**
* @brief Prometheus collector definition
*
@ -38,6 +54,12 @@ struct prometheus_collector {
sys_slist_t metrics;
/** Mutex to protect the metrics list manipulation */
struct k_mutex lock;
/** User callback function. If set, then the metric data is fetched
* via the function callback.
*/
prometheus_scrape_cb_t user_cb;
/** User data */
void *user_data;
};
/**
@ -46,12 +68,25 @@ struct prometheus_collector {
* This macro defines a Collector.
*
* @param _name The collector's name.
* @param ... Optional user callback function. If set, this function is called
* when the collector is scraped. The function should be of type
* prometheus_scrape_cb_t.
* Optional user data to pass to the user callback function.
*/
#define PROMETHEUS_COLLECTOR_DEFINE(_name) \
#define PROMETHEUS_COLLECTOR_DEFINE(_name, ...) \
STRUCT_SECTION_ITERABLE(prometheus_collector, _name) = { \
.name = STRINGIFY(_name), \
.metrics = SYS_SLIST_STATIC_INIT(&_name.metrics), \
.lock = Z_MUTEX_INITIALIZER(_name.lock), \
.user_cb = COND_CODE_0( \
NUM_VA_ARGS_LESS_1( \
LIST_DROP_EMPTY(__VA_ARGS__, _)), \
(NULL), \
(GET_ARG_N(1, __VA_ARGS__))), \
.user_data = COND_CODE_0( \
NUM_VA_ARGS_LESS_1(__VA_ARGS__), (NULL), \
(GET_ARG_N(1, \
GET_ARGS_LESS_N(1, __VA_ARGS__)))), \
}
/**

14
include/zephyr/net/prometheus/counter.h
View file

@ -33,6 +33,8 @@ struct prometheus_counter {
struct prometheus_metric base;
/** Value of the Prometheus counter metric */
uint64_t value;
/** User data */
void *user_data;
};
/**
@ -44,22 +46,30 @@ struct prometheus_counter {
* @param _name The counter metric name
* @param _desc Counter description
* @param _label Label for the metric. Additional labels can be added at runtime.
* @param _collector Collector to map this metric. Can be set to NULL if it not yet known.
* @param ... Optional user data specific to this metric instance.
*
* Example usage:
* @code{.c}
*
* PROMETHEUS_COUNTER_DEFINE(http_request_counter, "HTTP request counter",
* ({ .key = "http_request", .value = "request_count" }));
* ({ .key = "http_request", .value = "request_count" }),
* NULL);
* @endcode
*/
#define PROMETHEUS_COUNTER_DEFINE(_name, _desc, _label) \
#define PROMETHEUS_COUNTER_DEFINE(_name, _desc, _label, _collector, ...) \
STRUCT_SECTION_ITERABLE(prometheus_counter, _name) = { \
.base.name = STRINGIFY(_name), \
.base.type = PROMETHEUS_COUNTER, \
.base.description = _desc, \
.base.labels[0] = __DEBRACKET _label, \
.base.num_labels = 1, \
.base.collector = _collector, \
.value = 0ULL, \
.user_data = COND_CODE_0( \
NUM_VA_ARGS_LESS_1(LIST_DROP_EMPTY(__VA_ARGS__, _)), \
(NULL), \
(GET_ARG_N(1, __VA_ARGS__))), \
}
/**

14
include/zephyr/net/prometheus/gauge.h
View file

@ -31,6 +31,8 @@ struct prometheus_gauge {
struct prometheus_metric base;
/** Value of the Prometheus gauge metric */
double value;
/** User data */
void *user_data;
};
/**
@ -42,23 +44,31 @@ struct prometheus_gauge {
* @param _name The gauge metric name.
* @param _desc Gauge description
* @param _label Label for the metric. Additional labels can be added at runtime.
* @param _collector Collector to map this metric. Can be set to NULL if it not yet known.
* @param ... Optional user data specific to this metric instance.
*
* Example usage:
* @code{.c}
*
* PROMETHEUS_GAUGE_DEFINE(http_request_gauge, "HTTP request gauge",
* ({ .key = "http_request", .value = "request_count" }));
* ({ .key = "http_request", .value = "request_count" }),
* NULL);
*
* @endcode
*/
#define PROMETHEUS_GAUGE_DEFINE(_name, _desc, _label) \
#define PROMETHEUS_GAUGE_DEFINE(_name, _desc, _label, _collector, ...) \
STRUCT_SECTION_ITERABLE(prometheus_gauge, _name) = { \
.base.name = STRINGIFY(_name), \
.base.type = PROMETHEUS_GAUGE, \
.base.description = _desc, \
.base.labels[0] = __DEBRACKET _label, \
.base.num_labels = 1, \
.base.collector = _collector, \
.value = 0.0, \
.user_data = COND_CODE_0( \
NUM_VA_ARGS_LESS_1(LIST_DROP_EMPTY(__VA_ARGS__, _)), \
(NULL), \
(GET_ARG_N(1, __VA_ARGS__))), \
}
/**

14
include/zephyr/net/prometheus/histogram.h
View file

@ -51,6 +51,8 @@ struct prometheus_histogram {
double sum;
/** Total count of observations in the histogram */
unsigned long count;
/** User data */
void *user_data;
};
/**
@ -62,26 +64,34 @@ struct prometheus_histogram {
* @param _name The histogram metric name.
* @param _desc Histogram description
* @param _label Label for the metric. Additional labels can be added at runtime.
* @param _collector Collector to map this metric. Can be set to NULL if it not yet known.
* @param ... Optional user data specific to this metric instance.
*
* Example usage:
* @code{.c}
*
* PROMETHEUS_HISTOGRAM_DEFINE(http_request_histogram, "HTTP request histogram",
* ({ .key = "request_latency", .value = "request_latency_seconds" }));
* ({ .key = "request_latency", .value = "request_latency_seconds" }),
* NULL);
*
* @endcode
*/
#define PROMETHEUS_HISTOGRAM_DEFINE(_name, _desc, _label) \
#define PROMETHEUS_HISTOGRAM_DEFINE(_name, _desc, _label, _collector, ...) \
STRUCT_SECTION_ITERABLE(prometheus_histogram, _name) = { \
.base.name = STRINGIFY(_name), \
.base.type = PROMETHEUS_HISTOGRAM, \
.base.description = _desc, \
.base.labels[0] = __DEBRACKET _label, \
.base.num_labels = 1, \
.base.collector = _collector, \
.buckets = NULL, \
.num_buckets = 0, \
.sum = 0.0, \
.count = 0U, \
.user_data = COND_CODE_0( \
NUM_VA_ARGS_LESS_1(LIST_DROP_EMPTY(__VA_ARGS__, _)), \
(NULL), \
(GET_ARG_N(1, __VA_ARGS__))), \
}
/**

7
include/zephyr/net/prometheus/metric.h
View file

@ -49,6 +49,11 @@ struct prometheus_metric {
sys_snode_t node;
/** Back pointer to the collector that this metric belongs to */
struct prometheus_collector *collector;
/** Back pointer to the actual metric (counter, gauge, etc.).
* This is just a temporary solution, ultimate goal is to place
* this generic metrict struct into the actual metric struct.
*/
void *metric;
/** Type of the Prometheus metric. */
enum prometheus_metric_type type;
/** Name of the Prometheus metric. */
@ -59,6 +64,8 @@ struct prometheus_metric {
struct prometheus_label labels[MAX_PROMETHEUS_LABELS_PER_METRIC];
/** Number of labels associated with the Prometheus metric. */
int num_labels;
/** User defined data */
void *user_data;
/* Add any other necessary fields */
};

15
include/zephyr/net/prometheus/summary.h
View file

@ -32,6 +32,8 @@ struct prometheus_summary_quantile {
double quantile;
/** Value of the quantile */
double value;
/** User data */
void *user_data;
};
/**
@ -51,6 +53,8 @@ struct prometheus_summary {
double sum;
/** Total count of observations in the summary metric */
unsigned long count;
/** User data */
void *user_data;
};
/**
@ -62,6 +66,8 @@ struct prometheus_summary {
* @param _name The summary metric name.
* @param _desc Summary description
* @param _label Label for the metric. Additional labels can be added at runtime.
* @param _collector Collector to map this metric. Can be set to NULL if it not yet known.
* @param ... Optional user data specific to this metric instance.
*
*
* Example usage:
@ -69,22 +75,27 @@ struct prometheus_summary {
*
* PROMETHEUS_SUMMARY_DEFINE(http_request_summary, "HTTP request summary",
* ({ .key = "request_latency",
* .value = "request_latency_seconds" }));
* .value = "request_latency_seconds" }), NULL);
*
* @endcode
*/
#define PROMETHEUS_SUMMARY_DEFINE(_name, _desc, _label) \
#define PROMETHEUS_SUMMARY_DEFINE(_name, _desc, _label, _collector, ...) \
STRUCT_SECTION_ITERABLE(prometheus_summary, _name) = { \
.base.name = STRINGIFY(_name), \
.base.type = PROMETHEUS_SUMMARY, \
.base.description = _desc, \
.base.labels[0] = __DEBRACKET _label, \
.base.num_labels = 1, \
.base.collector = _collector, \
.quantiles = NULL, \
.num_quantiles = 0, \
.sum = 0.0, \
.count = 0U, \
.user_data = COND_CODE_0( \
NUM_VA_ARGS_LESS_1(LIST_DROP_EMPTY(__VA_ARGS__, _)), \
(NULL), \
(GET_ARG_N(1, __VA_ARGS__))), \
}
/**

2
samples/net/prometheus/src/main.c
View file

@ -146,7 +146,7 @@ static void setup_tls(void)
}
PROMETHEUS_COUNTER_DEFINE(http_request_counter, "HTTP request counter",
({ .key = "http_request", .value = "request_count" }));
({ .key = "http_request", .value = "request_count" }), NULL);
PROMETHEUS_COLLECTOR_DEFINE(test_collector);

14
subsys/net/lib/prometheus/formatter.c
View file

@ -63,6 +63,20 @@ int prometheus_format_exposition(struct prometheus_collector *collector, char *b
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&collector->metrics, metric, tmp, node) {
/* If there is a user callback, use it to update the metric data. */
if (collector->user_cb) {
ret = collector->user_cb(collector, metric, collector->user_data);
if (ret < 0) {
if (ret == -EAGAIN) {
/* Skip this metric for now */
continue;
}
LOG_ERR("Error in user callback (%d)", ret);
goto out;
}
}
/* write HELP line if available */
if (metric->description[0] != '\0') {
ret = write_metric_to_buffer(buffer + written, buffer_size - written,

8
tests/net/lib/prometheus/collector/src/main.c
View file

@ -10,7 +10,7 @@
#include <zephyr/net/prometheus/collector.h>
PROMETHEUS_COUNTER_DEFINE(test_counter_m, "Test counter",
({ .key = "test_counter", .value = "test" }));
({ .key = "test_counter", .value = "test" }), NULL);
PROMETHEUS_COLLECTOR_DEFINE(test_custom_collector);
@ -31,9 +31,11 @@ ZTEST(test_collector, test_prometheus_collector_register)
prometheus_collector_register_metric(&test_custom_collector, &test_counter_m.base);
counter = (struct prometheus_counter *)prometheus_collector_get_metric(
&test_custom_collector, "test_counter");
&test_custom_collector, "test_counter_m");
zassert_equal(counter, &test_counter_m, "Counter not found in collector");
zassert_equal_ptr(counter, &test_counter_m,
"Counter not found in collector (expected %p, got %p)",
&test_counter_m, counter);
zassert_equal(test_counter_m.value, 0, "Counter value is not 0");

3
tests/net/lib/prometheus/counter/src/main.c
View file

@ -9,7 +9,8 @@
#include <zephyr/net/prometheus/counter.h>
PROMETHEUS_COUNTER_DEFINE(test_counter_m, "Test counter",
({ .key = "test_counter", .value = "test" }));
({ .key = "test_counter", .value = "test" }),
NULL);
/**
* @brief Test prometheus_counter_inc

2
tests/net/lib/prometheus/gauge/src/main.c
View file

@ -9,7 +9,7 @@
#include <zephyr/net/prometheus/gauge.h>
PROMETHEUS_GAUGE_DEFINE(test_gauge_m, "Test gauge",
({ .key = "test", .value = "gauge" }));
({ .key = "test", .value = "gauge" }), NULL);
/**
* @brief Test prometheus_gauge_set

2
tests/net/lib/prometheus/histogram/src/main.c
View file

@ -9,7 +9,7 @@
#include <zephyr/net/prometheus/histogram.h>
PROMETHEUS_HISTOGRAM_DEFINE(test_histogram_m, "Test histogram",
({ .key = "test", .value = "histogram" }));
({ .key = "test", .value = "histogram" }), NULL);
/**
* @brief Test prometheus_histogram_observe

2
tests/net/lib/prometheus/summary/src/main.c
View file

@ -9,7 +9,7 @@
#include <zephyr/net/prometheus/summary.h>
PROMETHEUS_SUMMARY_DEFINE(test_summary_m, "Test summary",
({ .key = "test", .value = "summary" }));
({ .key = "test", .value = "summary" }), NULL);
/**
* @brief Test prometheus_summary_observe