From fd0a0de7da4f2db16cb4e48a23e91949a9a85b6b Mon Sep 17 00:00:00 2001
From: Aditya Prajapati <aditya@calyptia.com>
Date: Tue, 11 Oct 2022 21:42:35 +0530
Subject: [PATCH] out_opentelemetry: export traces

Signed-off-by: Aditya Prajapati <aditya@calyptia.com>
---
 plugins/out_opentelemetry/opentelemetry.c | 97 ++++++++++++++++++++++-
 plugins/out_opentelemetry/opentelemetry.h |  1 +
 2 files changed, 95 insertions(+), 3 deletions(-)

diff --git a/plugins/out_opentelemetry/opentelemetry.c b/plugins/out_opentelemetry/opentelemetry.c
index 73bf5d1977d..0de5b7c473f 100644
--- a/plugins/out_opentelemetry/opentelemetry.c
+++ b/plugins/out_opentelemetry/opentelemetry.c
@@ -30,6 +30,9 @@
 #include <cmetrics/cmetrics.h>
 #include <cmetrics/cmt_encode_opentelemetry.h>
 
+#include <ctraces/ctraces.h>
+#include <ctraces/ctr_decode_msgpack.h>
+
 extern cfl_sds_t cmt_encode_opentelemetry_create(struct cmt *cmt);
 extern void cmt_encode_opentelemetry_destroy(struct cmt *cmt);
 
@@ -428,6 +431,86 @@ static int process_metrics(struct flb_event_chunk *event_chunk,
     return result;
 }
 
+static int process_traces(struct flb_event_chunk *event_chunk,
+                          struct flb_output_flush *out_flush,
+                          struct flb_input_instance *ins, void *out_context,
+                          struct flb_config *config)
+{
+    int ok;
+    int ret;
+    int result;
+    cfl_sds_t encoded_chunk;
+    flb_sds_t buf = NULL;
+    size_t off = 0;
+    struct ctrace *ctr;
+    struct opentelemetry_context *ctx = out_context;
+
+    /* Initialize vars */
+    ctx = out_context;
+    ok = 0;
+    result = FLB_OK;
+
+    buf = flb_sds_create_size(event_chunk->size);
+    if (!buf) {
+        flb_plg_error(ctx->ins, "could not allocate outgoing buffer");
+        return FLB_RETRY;
+    }
+
+    flb_plg_debug(ctx->ins, "ctraces msgpack size: %lu",
+                  event_chunk->size);
+
+    ret = ctr_decode_msgpack_create(&ctr,
+                                    (char *) event_chunk->data,
+                                    event_chunk->size, &off);
+    if  (ret != ok) {
+        flb_plg_error(ctx->ins, "Error decoding msgpack encoded context");
+    }
+
+    /* Create a OpenTelemetry payload */
+    encoded_chunk = ctr_encode_opentelemetry_create(ctr);
+    if (encoded_chunk == NULL) {
+        flb_plg_error(ctx->ins,
+                      "Error encoding context as opentelemetry");
+        result = FLB_ERROR;
+        goto exit;
+    }
+
+    /* concat buffer */
+    flb_sds_cat_safe(&buf, encoded_chunk, flb_sds_len(encoded_chunk));
+
+    /* release */
+    ctr_encode_opentelemetry_destroy(encoded_chunk);
+    ctr_destroy(ctr);
+
+    flb_plg_debug(ctx->ins, "final payload size: %lu", flb_sds_len(buf));
+    if (buf && flb_sds_len(buf) > 0) {
+        /* Send HTTP request */
+        result = http_post(ctx, buf, flb_sds_len(buf),
+                           event_chunk->tag,
+                           flb_sds_len(event_chunk->tag),
+                           ctx->traces_uri);
+
+        /* Debug http_post() result statuses */
+        if (result == FLB_OK) {
+            flb_plg_debug(ctx->ins, "http_post result FLB_OK");
+        }
+        else if (result == FLB_ERROR) {
+            flb_plg_debug(ctx->ins, "http_post result FLB_ERROR");
+        }
+        else if (result == FLB_RETRY) {
+            flb_plg_debug(ctx->ins, "http_post result FLB_RETRY");
+        }
+    }
+    flb_sds_destroy(buf);
+    buf = NULL;
+
+exit:
+    if (buf) {
+        flb_sds_destroy(buf);
+    }
+    return result;
+}
+
 static int cb_opentelemetry_exit(void *data, struct flb_config *config)
 {
     struct opentelemetry_context *ctx;
@@ -462,12 +545,15 @@ static void cb_opentelemetry_flush(struct flb_event_chunk *event_chunk,
 {
     int result = FLB_RETRY;
 
-    if (ins->event_type == FLB_OUTPUT_METRICS || ins->event_type == FLB_INPUT_METRICS){
+    if (ins->event_type == FLB_INPUT_METRICS){
         result = process_metrics(event_chunk, out_flush, ins, out_context, config);
     }
-    else if (ins->event_type == FLB_INPUT_LOGS || ins->event_type == FLB_OUTPUT_LOGS){
+    else if (ins->event_type == FLB_INPUT_LOGS){
         result = process_logs(event_chunk, out_flush, ins, out_context, config);
     }
+    else if (ins->event_type == FLB_INPUT_TRACES){
+        result = process_traces(event_chunk, out_flush, ins, out_context, config);
+    }
     FLB_OUTPUT_RETURN(result);
 }
 
@@ -510,6 +596,11 @@ static struct flb_config_map config_map[] = {
      0, FLB_TRUE, offsetof(struct opentelemetry_context, logs_uri),
      "Specify an optional HTTP URI for the target OTel endpoint."
     },
+    {
+     FLB_CONFIG_MAP_STR, "traces_uri", "/v1/traces",
+     0, FLB_TRUE, offsetof(struct opentelemetry_context, traces_uri),
+     "Specify an optional HTTP URI for the target OTel endpoint."
+    },
     {
      FLB_CONFIG_MAP_BOOL, "log_response_payload", "true",
      0, FLB_TRUE, offsetof(struct opentelemetry_context, log_response_payload),
@@ -527,6 +618,6 @@ struct flb_output_plugin out_opentelemetry_plugin = {
     .cb_flush    = cb_opentelemetry_flush,
     .cb_exit     = cb_opentelemetry_exit,
     .config_map  = config_map,
-    .event_type  = FLB_OUTPUT_LOGS | FLB_OUTPUT_METRICS,
+    .event_type  = FLB_OUTPUT_LOGS,
     .flags       = FLB_OUTPUT_NET | FLB_IO_OPT_TLS,
 };
diff --git a/plugins/out_opentelemetry/opentelemetry.h b/plugins/out_opentelemetry/opentelemetry.h
index 659f0d64bb5..81693bb5e65 100644
--- a/plugins/out_opentelemetry/opentelemetry.h
+++ b/plugins/out_opentelemetry/opentelemetry.h
@@ -38,6 +38,7 @@ struct opentelemetry_context {
     int proxy_port;
 
     /* HTTP URI */
+    char *traces_uri;
     char *metrics_uri;
     char *logs_uri;
     char *host;