Merging upstream version 3.0.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 127 insertions, 0 deletions

diff --git a/addons/promex/include/promex/promex.h b/addons/promex/include/promex/promex.h
new file mode 100644
index 0000000..74ea2f1
--- /dev/null
+++ b/addons/promex/include/promex/promex.h
@@ -0,0 +1,127 @@
+/*
+ * include/promex/promex.h
+ * This file contains definitions, macros and inline functions dedicated to
+ * the prometheus exporter for HAProxy.
+ *
+ * Copyright 2024 Christopher Faulet <cfaulet@haproxy.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, version 2.1
+ * exclusively.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef _PROMEX_PROMEX_H
+#define _PROMEX_PROMEX_H
+
+#include <import/ist.h>
+
+#include <haproxy/api-t.h>
+#include <haproxy/list-t.h>
+
+#include <haproxy/stats.h>
+
+/* Prometheus exporter flags (ctx->flags) */
+#define PROMEX_FL_METRIC_HDR        0x00000001
+#define PROMEX_FL_INFO_METRIC       0x00000002
+#define PROMEX_FL_FRONT_METRIC      0x00000004
+#define PROMEX_FL_BACK_METRIC       0x00000008
+#define PROMEX_FL_SRV_METRIC        0x00000010
+#define PROMEX_FL_LI_METRIC         0x00000020
+#define PROMEX_FL_MODULE_METRIC     0x00000040
+#define PROMEX_FL_SCOPE_GLOBAL      0x00000080
+#define PROMEX_FL_SCOPE_FRONT       0x00000100
+#define PROMEX_FL_SCOPE_BACK        0x00000200
+#define PROMEX_FL_SCOPE_SERVER      0x00000400
+#define PROMEX_FL_SCOPE_LI          0x00000800
+#define PROMEX_FL_SCOPE_MODULE      0x00001000
+#define PROMEX_FL_NO_MAINT_SRV      0x00002000
+#define PROMEX_FL_EXTRA_COUNTERS    0x00004000
+#define PROMEX_FL_INC_METRIC_BY_DEFAULT 0x00008000
+
+#define PROMEX_FL_SCOPE_ALL (PROMEX_FL_SCOPE_GLOBAL | PROMEX_FL_SCOPE_FRONT | \
+			     PROMEX_FL_SCOPE_LI | PROMEX_FL_SCOPE_BACK | \
+			     PROMEX_FL_SCOPE_SERVER | PROMEX_FL_SCOPE_MODULE)
+
+/* The max number of labels per metric */
+#define PROMEX_MAX_LABELS 8
+
+/* Promtheus metric type (gauge or counter) */
+enum promex_mt_type {
+	PROMEX_MT_GAUGE   = 1,
+	PROMEX_MT_COUNTER = 2,
+};
+
+/* Describe a prometheus metric */
+struct promex_metric {
+	struct ist          n;      /* The metric name */
+	enum promex_mt_type type;   /* The metric type (gauge or counter) */
+	unsigned int        flags;  /* PROMEX_FL_* flags */
+};
+
+/* Describe a prometheus metric label. It is just a key/value pair */
+struct promex_label {
+	struct ist name;
+	struct ist value;
+};
+
+/* Entity used to expose custom metrics on HAProxy.
+ *
+ *     * start_metric_dump(): It is an optional callback function. If defined, it
+ *                            is responsible to initialize the dump context use
+ *                            as the first restart point.
+ *
+ *     * stop_metric_dump(): It is an optional callback function. If defined, it
+ *                           is responsible to deinit the dump context.
+ *
+ *     * metric_info(): This one is mandatory. It returns the info about the
+ *                      metric: name, type and flags and description.
+ *
+ *     * start_ts(): This one is mandatory, it initializes the context for a time
+ *                   series for a given metric. This context is the second
+ *                   restart point.
+ *
+ *    * next_ts(): This one is mandatory. It iterates on time series for a
+ *                 given metrics. It is also responsible to handle end of a
+ *                 time series and deinit the context.
+ *
+ *    * fill_ts(): It fills info on the time series for a given metric : the
+ *                 labels and the value.
+ */
+struct promex_module {
+	struct list list;
+	struct ist name;                                                  /* The promex module name */
+	int   (*metric_info)(unsigned int id,                             /* Return info for the given id */
+			     struct promex_metric *metric,
+			     struct ist *desc);
+	void *(*start_metrics_dump)();                                    /* Start a dump (may be NULL) */
+	void  (*stop_metrics_dump)(void *ctx);                            /* Stop a dump (may be NULL) */
+	void *(*start_ts)(void *ctx, unsigned int id);                    /* Start a time series for the given metric */
+	void *(*next_ts)(void *ctx, void *ts_ctx, unsigned int id);       /* move to the next time series for the given metric */
+	int   (*fill_ts)(void *ctx, void *ts_ctx, unsigned int id,        /* fill the time series for the given metric */
+			 struct promex_label *labels, struct field *field);
+
+	size_t nb_metrics;                                                /* # of metrics */
+};
+
+extern struct list promex_module_list;
+
+void promex_register_module(struct promex_module *m);
+
+#endif /* _PROMEX_PROMEX_H */
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ */