From ea5b9376077be1b65c729252f0591c1ec8dd678a Mon Sep 17 00:00:00 2001
From: 0Delta <0deltast@gmail.com>
Date: Mon, 25 Oct 2021 22:24:10 +0900
Subject: [PATCH] out_stackdriver: support stackdriver trace span (#4223)

logentry will be able to bind to span in the Google Cloud Web UI.

Specifically Cloud Trace (Stackdriver),
the `logging.googleapis.com/traceId` field is
moved to the top of the log entry and renames it to `traceId`.

Signed-off-by: 0Delta <0deltast@gmail.com>
---
 plugins/out_stackdriver/stackdriver.c         | 24 +++++++++++++++++++
 plugins/out_stackdriver/stackdriver.h         |  2 ++
 plugins/out_stackdriver/stackdriver_conf.c    |  8 +++++++
 .../data/stackdriver/stackdriver_test_trace.h |  3 ++-
 4 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/plugins/out_stackdriver/stackdriver.c b/plugins/out_stackdriver/stackdriver.c
index f3a6f33fbb7..a68ab63b2d9 100644
--- a/plugins/out_stackdriver/stackdriver.c
+++ b/plugins/out_stackdriver/stackdriver.c
@@ -1288,6 +1288,7 @@ static int pack_json_payload(int insert_id_extracted,
         ctx->labels_key,
         ctx->severity_key,
         ctx->trace_key,
+        ctx->span_id_key,
         ctx->log_name_key,
         stream
         /* more special fields are required to be added, but, if this grows with more
@@ -1469,6 +1470,10 @@ static int stackdriver_format(struct flb_config *config,
     char stackdriver_trace[PATH_MAX];
     const char *new_trace;
 
+    /* Parameters for spanID */
+    int spanid_extracted = FLB_FALSE;
+    flb_sds_t spanid;
+
     /* Parameters for log name */
     int log_name_extracted = FLB_FALSE;
     flb_sds_t log_name = NULL;
@@ -1822,6 +1827,7 @@ static int stackdriver_format(struct flb_config *config,
          *  "jsonPayload": {...},
          *  "timestamp": "...",
          *  "trace": "..."
+         *  "spanId": "..."
          * }
          */
         entry_size = 3;
@@ -1842,6 +1848,14 @@ static int stackdriver_format(struct flb_config *config,
             entry_size += 1;
         }
 
+        /* Extract spanid */
+        spanid_extracted = FLB_FALSE;
+        if (ctx->span_id_key
+            && get_string(&spanid, obj, ctx->span_id_key) == 0) {
+            spanid_extracted = FLB_TRUE;
+            entry_size += 1;
+        }
+
         /* Extract log name */
         log_name_extracted = FLB_FALSE;
         if (ctx->log_name_key
@@ -1946,6 +1960,16 @@ static int stackdriver_format(struct flb_config *config,
             flb_sds_destroy(trace);
         }
 
+        /* Add spanId into the log entry */
+        if (spanid_extracted == FLB_TRUE) {
+            msgpack_pack_str(&mp_pck, 6);
+            msgpack_pack_str_body(&mp_pck, "spanId", 6);
+            len = flb_sds_len(spanid);
+            msgpack_pack_str(&mp_pck, len);
+            msgpack_pack_str_body(&mp_pck, spanid, len);
+            flb_sds_destroy(spanid);
+        }
+
         /* Add insertId field into the log entry */
         if (insert_id_extracted == FLB_TRUE) {
             msgpack_pack_str(&mp_pck, 8);
diff --git a/plugins/out_stackdriver/stackdriver.h b/plugins/out_stackdriver/stackdriver.h
index ee4b462e3c7..5aafc6c1186 100644
--- a/plugins/out_stackdriver/stackdriver.h
+++ b/plugins/out_stackdriver/stackdriver.h
@@ -54,6 +54,7 @@
 #define DEFAULT_LABELS_KEY "logging.googleapis.com/labels"
 #define DEFAULT_SEVERITY_KEY "logging.googleapis.com/severity"
 #define DEFAULT_TRACE_KEY "logging.googleapis.com/trace"
+#define DEFAULT_SPANID_KEY "logging.googleapis.com/spanId"
 #define DEFAULT_LOG_NAME_KEY "logging.googleapis.com/logName"
 #define DEFAULT_INSERT_ID_KEY "logging.googleapis.com/insertId"
 #define SOURCELOCATION_FIELD_IN_JSON "logging.googleapis.com/sourceLocation"
@@ -130,6 +131,7 @@ struct flb_stackdriver {
     flb_sds_t resource;
     flb_sds_t severity_key;
     flb_sds_t trace_key;
+    flb_sds_t span_id_key;
     flb_sds_t log_name_key;
     bool autoformat_stackdriver_trace;
 
diff --git a/plugins/out_stackdriver/stackdriver_conf.c b/plugins/out_stackdriver/stackdriver_conf.c
index 15e9b9916d8..610788e65a6 100644
--- a/plugins/out_stackdriver/stackdriver_conf.c
+++ b/plugins/out_stackdriver/stackdriver_conf.c
@@ -311,6 +311,14 @@ struct flb_stackdriver *flb_stackdriver_conf_create(struct flb_output_instance *
         ctx->trace_key = flb_sds_create(DEFAULT_TRACE_KEY);
     }
 
+    tmp = flb_output_get_property("span_id_key", ins);
+    if (tmp) {
+        ctx->span_id_key = flb_sds_create(tmp);
+    }
+    else {
+        ctx->span_id_key = flb_sds_create(DEFAULT_SPANID_KEY);
+    }
+
     tmp = flb_output_get_property("log_name_key", ins);
     if (tmp) {
         ctx->log_name_key = flb_sds_create(tmp);
diff --git a/tests/runtime/data/stackdriver/stackdriver_test_trace.h b/tests/runtime/data/stackdriver/stackdriver_test_trace.h
index 15c7bc911ba..44cf011398d 100644
--- a/tests/runtime/data/stackdriver/stackdriver_test_trace.h
+++ b/tests/runtime/data/stackdriver/stackdriver_test_trace.h
@@ -2,5 +2,6 @@
 	"1591111124," \
 	"{"	\
         "\"trace\": \"test-trace-id-xyz\"" \
+        "\"spanId\": \"test-span-id-abc\"" \
 	"}]"
-	
\ No newline at end of file
+