WIP: Don't Review : Changes to support trust incoming spans

instrumentation/otel-webserver-module/README.md

@@ -60,6 +60,7 @@ Monitoring individual modules is crucial to the instrumentation of Apache web se
 |*ApacheModuleSegmentParameter*                  |                 | OPTIONAL: Specify the segment count or segment numbers that you want to display for Span Creation|
 |*ApacheModuleOtelExporterHeaders*               |                 | OPTIONAL: OTEL Exporter header info or Metadata like API key for OTLP endpoint. a list of key value pairs, and these are expected to be represented in a format matching to the W3C Correlation-Context, except that additional semi-colon delimited metadata is not supported, i.e.: key1=value1,key2=value2. |
 
+
 A sample configuration is mentioned in [opentelemetry_module.conf](https://github.com/cisco-open/otel-webserver-module/blob/main/opentelemetry_module.conf)
 
 ### Build and Installation
@@ -176,6 +177,7 @@ Currently, Nginx Webserver module monitores some fixed set of modules, which get
 |*NginxModuleRequestHeaders*                    |                 | OPTIONAL: Specify the request headers to be captured in the span attributes. The headers are Case-Sensitive and should be comma-separated. e.g.```NginxModuleRequestHeaders               Accept-Charset,Accept-Encoding,User-Agent;```|
 |*NginxModuleResponseHeaders*                   |                  | OPTIONAL: Specify the response headers to be captured in the span attributes. The headers are Case-Sensitive and should be comma-separated. e.g.```NginxModuleResponseHeaders                  Content-Length,Content-Type;```|
 |*NginxModuleOtelExporterOtlpHeaders*           |                  | OPTIONAL: OTEL exporter headers like Meta data related exposrted end point. a list of key value pairs, and these are expected to be represented in a format matching to the W3C Correlation-Context, except that additional semi-colon delimited metadata is not supported, i.e.: key1=value1,key2=value2.|
+|*NginxModuleTrustIncomingSpans*                |                  | OPTIONAL: Enables or disables using spans from incoming requests as parent for created ones. (default: ON).|
 
 ### Build and Installation
 #### Prerequisites

instrumentation/otel-webserver-module/conf/nginx/opentelemetry_module.conf

@@ -19,4 +19,5 @@ NginxModuleResolveBackends ON;
 NginxModuleTraceAsError ON;
 #NginxModuleWebserverContext DemoService DemoServiceNamespace DemoInstanceId
 #NginxModuleSegmentType custom
-#NginxModuleSegmentParameter 15,1,6,7
+#NginxModuleSegmentParameter 15,1,6,7
+NginxModuleTrustIncomingSpans ON;

instrumentation/otel-webserver-module/include/core/sdkwrapper/SdkWrapper.h

@@ -40,6 +40,7 @@ class SdkWrapper : public ISdkWrapper{
 
 	void PopulatePropagationHeaders(
 		std::unordered_map<std::string, std::string>& carrier) override;
+	//opentelemetry::trace::SpanContext GetCurrentSpan(opentelemetry::context::Context context);
 
 private:
 	trace::SpanKind GetTraceSpanKind(const SpanKind& kind);

instrumentation/otel-webserver-module/src/core/sdkwrapper/ScopedSpan.cpp

@@ -30,6 +30,7 @@ ScopedSpan::ScopedSpan(
 {
 	trace::StartSpanOptions options{};
 	options.kind = kind;
+	//options.parent = GetCurrentSpan(incomingContext);
 	mSpan = sdkHelperFactory->GetTracer()->StartSpan(name, attributes, options);
 	mScope.reset(new trace::Scope(mSpan));
 	mSpanKind = kind;

instrumentation/otel-webserver-module/src/core/sdkwrapper/SdkWrapper.cpp

@@ -67,6 +67,15 @@ std::shared_ptr<IScopedSpan> SdkWrapper::CreateSpan(
 	}
 }
 
+/*opentelemetry::trace::SpanContext SdkWrapper::GetCurrentSpan(opentelemetry::context::Context context) {
+  opentelemetry::context::ContextValue span = context.GetValue(trace::kSpanKey);
+  if (nostd::holds_alternative<nostd::shared_ptr<trace::Span>>(span)) {
+    return nostd::get<opentelemetry::nostd::shared_ptr<trace::Span>>(span).get()->GetContext();
+  }
+
+  return trace::SpanContext::GetInvalid();
+}*/
+
 void SdkWrapper::PopulatePropagationHeaders(
 	std::unordered_map<std::string, std::string>& carrier) {
 

instrumentation/otel-webserver-module/src/nginx/ngx_http_opentelemetry_module.c

@@ -286,6 +286,13 @@ static ngx_command_t ngx_http_opentelemetry_commands[] = {
       offsetof(ngx_http_opentelemetry_loc_conf_t, nginxModuleTraceAsError),
       NULL},
 
+    { ngx_string("NginxModuleTrustIncomingSpans"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_flag_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_opentelemetry_loc_conf_t, nginxModuleTrustIncomingSpans),
+      NULL},
+
     { ngx_string("NginxModuleReportAllInstrumentedModules"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
       ngx_conf_set_flag_slot,
@@ -437,6 +444,7 @@ static void* ngx_http_opentelemetry_create_loc_conf(ngx_conf_t *cf)
     conf->nginxModuleTraceAsError              = NGX_CONF_UNSET;
     conf->nginxModuleOtelMaxQueueSize          = NGX_CONF_UNSET;
     conf->nginxModuleOtelSslEnabled            = NGX_CONF_UNSET;
+    conf->nginxModuleTrustIncomingSpans        = NGX_CONF_UNSET;
 
     return conf;
 }
@@ -453,6 +461,7 @@ static char* ngx_http_opentelemetry_merge_loc_conf(ngx_conf_t *cf, void *parent,
     ngx_conf_merge_value(conf->nginxModuleTraceAsError, prev->nginxModuleTraceAsError, 0);
     ngx_conf_merge_value(conf->nginxModuleMaskCookie, prev->nginxModuleMaskCookie, 0);
     ngx_conf_merge_value(conf->nginxModuleMaskSmUser, prev->nginxModuleMaskSmUser, 0);
+    ngx_conf_merge_value(conf->nginxModuleTrustIncomingSpans, prev->nginxModuleTrustIncomingSpans, 1);
 
     ngx_conf_merge_str_value(conf->nginxModuleOtelSpanExporter, prev->nginxModuleOtelSpanExporter, "");
     ngx_conf_merge_str_value(conf->nginxModuleOtelExporterEndpoint, prev->nginxModuleOtelExporterEndpoint, "");
@@ -711,11 +720,13 @@ static OTEL_SDK_STATUS_CODE otel_startInteraction(ngx_http_request_t* r, const c
     if(ctx && ctx->otel_req_handle_key)
     {
         ngx_flag_t resolveBackends = false;
+        ngx_flag_t trustIncomingSpans = false;
         ngx_http_opentelemetry_loc_conf_t* conf;
         conf = ngx_http_get_module_loc_conf(r, ngx_http_opentelemetry_module);
         if(conf)
         {
             resolveBackends = conf->nginxModuleResolveBackends;
+            trustIncomingSpans = conf->nginxModuleTrustIncomingSpans;
         }
         OTEL_SDK_ENV_RECORD* propagationHeaders = ngx_pcalloc(r->pool, 5 * sizeof(OTEL_SDK_ENV_RECORD));
         if (propagationHeaders == NULL)
@@ -757,6 +768,7 @@ static void otel_payload_decorator(ngx_http_request_t* r, OTEL_SDK_ENV_RECORD* p
    ngx_http_core_main_conf_t  *cmcf;
    ngx_uint_t       nelts;
 
+
    part = &r->headers_in.headers.part;
    header = (ngx_table_elt_t*)part->elts;
    nelts = part->nelts;
@@ -1477,6 +1489,7 @@ static void traceConfig(ngx_http_request_t *r, ngx_http_opentelemetry_loc_conf_t
                                                       "(ReportAllInstrumentedModules=\"%ld\")"
                                                       "(MaskCookie=\"%ld\")"
                                                       "(MaskSmUser=\"%ld\")"
+                                                      "(TrustIncomingSpans=\"%ld\")"
                                                       "(SegmentType=\"%s\")"
                                                       "(SegmentParameter=\"%s\")"
                                                       " }",
@@ -1500,6 +1513,7 @@ static void traceConfig(ngx_http_request_t *r, ngx_http_opentelemetry_loc_conf_t
                                                       conf->nginxModuleReportAllInstrumentedModules,
                                                       conf->nginxModuleMaskCookie,
                                                       conf->nginxModuleMaskSmUser,
+                                                      conf->nginxModuleTrustIncomingSpans,
                                                       (conf->nginxModuleSegmentType).data,
                                                       (conf->nginxModuleSegmentParameter).data);
 }

instrumentation/otel-webserver-module/src/nginx/ngx_http_opentelemetry_module.h

@@ -91,6 +91,7 @@ typedef struct {
     ngx_flag_t  nginxModuleReportAllInstrumentedModules;
     ngx_flag_t	nginxModuleResolveBackends;
     ngx_flag_t	nginxModuleTraceAsError;
+    ngx_flag_t  nginxModuleTrustIncomingSpans;
     ngx_flag_t  nginxModuleMaskCookie;
     ngx_flag_t  nginxModuleMaskSmUser;
     ngx_str_t   nginxModuleCookieMatchPattern;