commit cc2947c0070faac0805478381f13956bb2775621 Author: David Goulet dgoulet@torproject.org Date: Thu May 6 10:54:50 2021 -0400
metrics: Print once the Promtheus comments
An entry can have multiple labels but only print once the comments at the first one. This follows the Promtheus best practices.
Signed-off-by: David Goulet dgoulet@torproject.org --- src/lib/metrics/metrics_store.c | 10 ++++++++-- src/lib/metrics/prometheus.c | 11 +++++++---- src/lib/metrics/prometheus.h | 2 +- 3 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/src/lib/metrics/metrics_store.c b/src/lib/metrics/metrics_store.c index 4cab5245f3..1a520f4921 100644 --- a/src/lib/metrics/metrics_store.c +++ b/src/lib/metrics/metrics_store.c @@ -34,7 +34,8 @@ struct metrics_store_t { };
/** Function pointer to the format function of a specific driver. */ -typedef void (fmt_driver_fn_t)(const metrics_store_entry_t *, buf_t *); +typedef void (fmt_driver_fn_t)(const metrics_store_entry_t *, buf_t *, + bool no_comment);
/** Helper: Free a single entry in a metrics_store_t taking a void pointer * parameter. */ @@ -47,6 +48,8 @@ metrics_store_free_void(void *p) smartlist_free(list); }
+#include <stdio.h> + /** Put the given store output in the buffer data and use the format function * given in fmt to get it for each entry. */ static void @@ -57,8 +60,11 @@ get_output(const metrics_store_t *store, buf_t *data, fmt_driver_fn_t fmt) tor_assert(fmt);
STRMAP_FOREACH(store->entries, key, const smartlist_t *, entries) { + /* Indicate that we've formatted the coment already for the entries. */ + bool comment_formatted = false; SMARTLIST_FOREACH_BEGIN(entries, const metrics_store_entry_t *, entry) { - fmt(entry, data); + fmt(entry, data, comment_formatted); + comment_formatted = true; } SMARTLIST_FOREACH_END(entry); } STRMAP_FOREACH_END; } diff --git a/src/lib/metrics/prometheus.c b/src/lib/metrics/prometheus.c index 65241ed6c1..aac23ac92e 100644 --- a/src/lib/metrics/prometheus.c +++ b/src/lib/metrics/prometheus.c @@ -42,14 +42,17 @@ format_labels(smartlist_t *labels)
/** Format the given entry in to the buffer data. */ void -prometheus_format_store_entry(const metrics_store_entry_t *entry, buf_t *data) +prometheus_format_store_entry(const metrics_store_entry_t *entry, buf_t *data, + bool no_comment) { tor_assert(entry); tor_assert(data);
- buf_add_printf(data, "# HELP %s %s\n", entry->name, entry->help); - buf_add_printf(data, "# TYPE %s %s\n", entry->name, - metrics_type_to_str(entry->type)); + if (!no_comment) { + buf_add_printf(data, "# HELP %s %s\n", entry->name, entry->help); + buf_add_printf(data, "# TYPE %s %s\n", entry->name, + metrics_type_to_str(entry->type)); + } buf_add_printf(data, "%s%s %" PRIi64 "\n", entry->name, format_labels(entry->labels), metrics_store_entry_get_value(entry)); diff --git a/src/lib/metrics/prometheus.h b/src/lib/metrics/prometheus.h index 19770e7911..faa7681daa 100644 --- a/src/lib/metrics/prometheus.h +++ b/src/lib/metrics/prometheus.h @@ -13,6 +13,6 @@ #include "lib/metrics/metrics_store_entry.h"
void prometheus_format_store_entry(const metrics_store_entry_t *entry, - buf_t *data); + buf_t *data, bool no_comment);
#endif /* !defined(TOR_LIB_METRICS_PROMETHEUS_H) */