From 586c5b536683294981181e334b5af264a4615c74 Mon Sep 17 00:00:00 2001
From: Ava Hahn <a.hahn@f5.com>
Date: Thu, 7 Nov 2024 14:10:57 -0800
Subject: otel: configuration items and their validation

Adds code responsible for users to apply the `telemetry` configuration
options.

configuration snippet as follows:
{
    "settings": {
        "telemetry": {
            "batch_size": 20,
            "endpoint": "http://lgtm:4318/v1/traces",
            "protocol": "http",
            "sampling_ratio": 1
        }
    },
    "listeners": {
        "*:80": {
            "pass": "routes"
        }
    },
    "routes": [
        {
            "match": {
                "headers": {
                    "accept": "*text/html*"
                }
            },
            "action": {
                "share": "/usr/share/unit/welcome/welcome.html"
            }
        },
        {
            "action": {
                "share": "/usr/share/unit/welcome/welcome.md"
            }
        }
    ]
}

Signed-off-by: Ava Hahn <a.hahn@f5.com>
Signed-off-by: Gabor Javorszky <g.javorszky@f5.com>
---
 src/nxt_router.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

(limited to 'src/nxt_router.c')

diff --git a/src/nxt_router.c b/src/nxt_router.c
index 076cd134..44ea823b 100644
--- a/src/nxt_router.c
+++ b/src/nxt_router.c
@@ -24,6 +24,11 @@
 
 #define NXT_SHARED_PORT_ID  0xFFFFu
 
+#if (NXT_HAVE_OTEL)
+#define NXT_OTEL_BATCH_DEFAULT     128
+#define NXT_OTEL_SAMPLING_DEFAULT  1
+#endif
+
 typedef struct {
     nxt_str_t         type;
     uint32_t          processes;
@@ -1635,6 +1640,12 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
 #endif
 #if (NXT_HAVE_NJS)
     nxt_conf_value_t            *js_module;
+#endif
+#if (NXT_HAVE_OTEL)
+    double                      telemetry_sample_fraction, telemetry_batching;
+    nxt_str_t                   telemetry_endpoint, telemetry_proto;
+    nxt_conf_value_t            *otel, *otel_endpoint, *otel_sampling,
+                                *otel_batching, *otel_proto;
 #endif
     nxt_conf_value_t            *root, *conf, *http, *value, *websocket;
     nxt_conf_value_t            *applications, *application, *settings;
@@ -1671,6 +1682,17 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
                                 nxt_string("/settings/http/websocket");
     static const nxt_str_t  forwarded_path = nxt_string("/forwarded");
     static const nxt_str_t  client_ip_path = nxt_string("/client_ip");
+#if (NXT_HAVE_OTEL)
+    static const nxt_str_t  telemetry_path = nxt_string("/settings/telemetry");
+    static const nxt_str_t  telemetry_endpoint_path =
+                                nxt_string("/settings/telemetry/endpoint");
+    static const nxt_str_t  telemetry_batch_path =
+                                nxt_string("/settings/telemetry/batch_size");
+    static const nxt_str_t  telemetry_sample_path =
+                                nxt_string("/settings/telemetry/sampling_ratio");
+    static const nxt_str_t  telemetry_proto_path =
+                                nxt_string("/settings/telemetry/protocol");
+#endif
 
     root = nxt_conf_json_parse(tmcf->mem_pool, start, end, NULL);
     if (root == NULL) {
@@ -2172,6 +2194,34 @@ nxt_router_conf_create(nxt_task_t *task, nxt_router_temp_conf_t *tmcf,
 
 #endif
 
+#if (NXT_HAVE_OTEL)
+    otel = nxt_conf_get_path(root, &telemetry_path);
+
+    if (otel) {
+        otel_endpoint = nxt_conf_get_path(root, &telemetry_endpoint_path);
+        otel_batching = nxt_conf_get_path(root, &telemetry_batch_path);
+        otel_sampling = nxt_conf_get_path(root, &telemetry_sample_path);
+        otel_proto    = nxt_conf_get_path(root, &telemetry_proto_path);
+
+        nxt_conf_get_string(otel_endpoint, &telemetry_endpoint);
+        nxt_conf_get_string(otel_proto, &telemetry_proto);
+
+        telemetry_batching = otel_batching
+            ? nxt_conf_get_number(otel_batching)
+            : NXT_OTEL_BATCH_DEFAULT;
+
+        telemetry_sample_fraction = otel_sampling
+            ? nxt_conf_get_number(otel_sampling)
+            : NXT_OTEL_SAMPLING_DEFAULT;
+
+        nxt_otel_rs_init(&nxt_otel_log_callback, &telemetry_endpoint,
+                         &telemetry_proto, telemetry_sample_fraction,
+                         telemetry_batching);
+    } else {
+        nxt_otel_rs_uninit();
+    }
+#endif
+
     nxt_queue_add(&deleting_sockets, &router->sockets);
     nxt_queue_init(&router->sockets);
 
-- 
cgit