Add HTTP/protobuf OTLP export support for Apache and Nginx modules

instrumentation/otel-webserver-module/README.md

@@ -59,6 +59,7 @@ Monitoring individual modules is crucial to the instrumentation of Apache web se
 |*ApacheModuleSegmentType*                       |                 | OPTIONAL: Specify the string (FIRST/LAST/CUSTOM) to be filtered for Span Name Creation|
 |*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. |
+|*ApacheModuleOtelExporterOtlpProtocol*          | http/protobuf   | OPTIONAL: OTLP export protocol. Supported values are "grpc", "http/protobuf", and "http/json". Can also be set via OTEL_EXPORTER_OTLP_TRACES_PROTOCOL or OTEL_EXPORTER_OTLP_PROTOCOL environment variables. |
 
 A sample configuration is mentioned in [opentelemetry_module.conf](https://github.com/open-telemetry/opentelemetry-cpp-contrib/blob/main/instrumentation/otel-webserver-module/opentelemetry_module.conf)
 
@@ -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.|
+|*NginxModuleOtelExporterOtlpProtocol*          | http/protobuf    | OPTIONAL: OTLP export protocol. Supported values are "grpc", "http/protobuf", and "http/json". Can also be set via OTEL_EXPORTER_OTLP_TRACES_PROTOCOL or OTEL_EXPORTER_OTLP_PROTOCOL environment variables.|
 |*NginxModuleTrustIncomingSpans*           | ON               | OPTIONAL: Specify if you want to correlate Nginx instrumented traces and spans with incoming requests.|
 |*NginxModuleAttributes*           |                | OPTIONAL: Can be used to pass additionalccustom attributes to the span, nginx variables are also supported. All elements must be separated by a space, and different attribute key value pairs must be separated by a comma( even the comma needs to be separated by space). e.g. ```NginxModuleAttributes     Key1 Value1 , Key2 $request_uri;``` |
 |*NginxModuleIgnorePaths*           |               | OPTIONAL: Request URIs matching the Regex will not be monitored. Multiple space separated Regex can be provided( `'\'` symbol needs to be used carefully, Nginx treats `'\'` as a escape sequence, thus if the Regex sequence contains a `'\'`, it need to be replaced by `'\\'`, likewise if sequence contains `'\\'`, it need to be written as `'\\\\'` e.g. `.*\.html` -> `.*\\.html` ) e.g. ```NginxModuleIgnorePaths               .*\\.html /test_.*;```|

instrumentation/otel-webserver-module/build.gradle

@@ -189,6 +189,8 @@ task stageLibrary(type: Copy) {
     from("${modDepDir}/opentelemetry/${cppSDKVersion}/lib/libopentelemetry_otlp_recordable.so") { it.into "sdk_lib/lib" }
     from("${modDepDir}/opentelemetry/${cppSDKVersion}/lib/libopentelemetry_exporter_ostream_span.so") { it.into "sdk_lib/lib" }
     from("${modDepDir}/opentelemetry/${cppSDKVersion}/lib/libopentelemetry_exporter_otlp_grpc.so") { it.into "sdk_lib/lib" }
+    from("${modDepDir}/opentelemetry/${cppSDKVersion}/lib/libopentelemetry_exporter_otlp_http.so") { it.into "sdk_lib/lib" }
+    from("${modDepDir}/opentelemetry/${cppSDKVersion}/lib/libopentelemetry_http_client_curl.so") { it.into "sdk_lib/lib" }
     from("dist/opentelemetry_sdk_log4cxx.xml.template") { it.into "conf" }
     from("dist/install.${scriptExt}") { it.fileMode 0700 }
 

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

@@ -2,6 +2,7 @@ NginxModuleEnabled ON;
 #NginxModule Otel Exporter details
 NginxModuleOtelSpanExporter otlp;
 NginxModuleOtelExporterEndpoint docker.for.mac.localhost:4317;
+#NginxModuleOtelExporterOtlpProtocol http/protobuf;
 #NginxModuleOtelExporterOtlpHeaders Authorization=AuthorizationToken;
 # SSL Certificates
 #NginxModuleOtelSslEnabled ON

instrumentation/otel-webserver-module/include/apache/ApacheConfig.h

@@ -42,6 +42,9 @@ class otel_cfg
     const char* getOtelExporterOtlpHeaders() { return otelExporterOtlpHeaders; }
     int otelExporterOtlpHeadersInitialized() { return otelExporterOtlpHeaders_initialized; }
 
+    const char* getOtelExporterOtlpProtocol() { return otelExporterOtlpProtocol; }
+    int otelExporterOtlpProtocolInitialized() { return otelExporterOtlpProtocol_initialized; }
+
     int getOtelSslEnabled() { return otelSslEnabled; }
     int getOtelSslEnabledInitialized() { return otelSslEnabled_initialized; }
 
@@ -129,6 +132,9 @@ class otel_cfg
     const char *otelExporterOtlpHeaders;   // OPTIONAL: AppDynamics  Custom metadata for OTEL Exporter EX: OTEL_EXPORTER_OTLP_HEADERS="api-key=key,other-config-value=value"
     int otelExporterOtlpHeaders_initialized;
 
+    const char *otelExporterOtlpProtocol;  // OPTIONAL: OTLP export protocol: grpc, http/protobuf, http/json (default: http/protobuf)
+    int otelExporterOtlpProtocol_initialized;
+
     int otelSslEnabled;      // OPTIONAL: Decision whether connection to the Exporter endpoint is secured
     int otelSslEnabled_initialized;
 
@@ -231,6 +237,7 @@ class ApacheConfigHandlers
     static const char* otel_set_otelExporterType(cmd_parms *cmd, void *conf, const char *arg);
     static const char* otel_set_otelExporterEndpoint(cmd_parms *cmd, void *conf, const char *arg);
     static const char* otel_set_otelExporterOtlpHeaders(cmd_parms *cmd, void *conf, const char *arg);
+    static const char* otel_set_otelExporterOtlpProtocol(cmd_parms *cmd, void *conf, const char *arg);
     static const char* otel_set_otelSslEnabled(cmd_parms *cmd, void *conf, const char *arg);
     static const char* otel_set_otelSslCertificatePath(cmd_parms *cmd, void *conf, const char *arg);
     static const char* otel_set_otelProcessorType(cmd_parms *cmd, void *conf, const char *arg);

instrumentation/otel-webserver-module/include/apache/ApacheHooks.h

@@ -33,7 +33,7 @@ class ApacheHooks
     static const char* OTEL_INTERACTION_HANDLE_KEY;
     static const char* OTEL_REQ_HANDLE_KEY;
     static const int LOWEST_HTTP_ERROR_CODE = 400;
-    static const int CONFIG_COUNT = 17; // Number of key value pairs in config
+    static const int CONFIG_COUNT = 18; // Number of key value pairs in config
     static const std::initializer_list<const char*> httpHeaders;
     static void registerHooks(apr_pool_t *p);
 

instrumentation/otel-webserver-module/include/core/api/OpentelemetrySdk.h

@@ -28,6 +28,7 @@
 #define OTEL_SDK_ENV_OTEL_EXPORTER_TYPE "OTEL_SDK_ENV_OTEL_EXPORTER_TYPE"
 #define OTEL_SDK_ENV_OTEL_EXPORTER_ENDPOINT "OTEL_SDK_ENV_OTEL_EXPORTER_ENDPOINT"             /*required*/
 #define OTEL_SDK_ENV_OTEL_EXPORTER_OTLPHEADERS "OTEL_SDK_ENV_OTEL_EXPORTER_OTLPHEADERS"             /*optional*/
+#define OTEL_SDK_ENV_OTEL_EXPORTER_OTLP_PROTOCOL "OTEL_SDK_ENV_OTEL_EXPORTER_OTLP_PROTOCOL"   /*optional: grpc, http/protobuf, http/json*/
 #define OTEL_SDK_ENV_OTEL_SSL_ENABLED "OTEL_SDK_ENV_OTEL_SSL_ENABLED"             /*optional*/
 #define OTEL_SDK_ENV_OTEL_SSL_CERTIFICATE_PATH "OTEL_SDK_ENV_OTEL_SSL_CERTIFICATE_PATH"   /*optional*/
 #define OTEL_SDK_ENV_OTEL_PROCESSOR_TYPE "OTEL_SDK_ENV_OTEL_PROCESSOR_TYPE"

instrumentation/otel-webserver-module/include/core/api/TenantConfig.h

@@ -46,6 +46,7 @@ class TenantConfig
     const std::string& getOtelExporterType() const {return otelExporterType;}
     const std::string& getOtelExporterEndpoint() const {return otelExporterEndpoint;}
     const std::string& getOtelExporterOtlpHeaders() const {return otelExporterOtlpHeaders;}
+    const std::string& getOtelExporterOtlpProtocol() const {return otelExporterOtlpProtocol;}
     const std::string& getOtelProcessorType() const {return otelProcessorType;}
     const std::string& getOtelPropagatorType() const {return otelPropagatorType;}
     const unsigned getOtelMaxQueueSize() const {return otelMaxQueueSize;}
@@ -64,6 +65,7 @@ class TenantConfig
     void setOtelExporterType(const std::string& otelExporterType) { this->otelExporterType = otelExporterType; }
     void setOtelExporterEndpoint(const std::string& otelExporterEndpoint) { this->otelExporterEndpoint = otelExporterEndpoint; }
     void setOtelExporterOtlpHeaders(const std::string& otelExporterOtlpHeaders) { this->otelExporterOtlpHeaders = otelExporterOtlpHeaders; }
+    void setOtelExporterOtlpProtocol(const std::string& otelExporterOtlpProtocol) { this->otelExporterOtlpProtocol = otelExporterOtlpProtocol; }
     void setOtelProcessorType(const std::string& otelProcessorType) { this->otelProcessorType = otelProcessorType; }
     void setOtelPropagatorType(const std::string& otelPropagatorType) { this->otelPropagatorType = otelPropagatorType; }
     void setOtelMaxQueueSize(const unsigned int otelMaxQueueSize) { this->otelMaxQueueSize = otelMaxQueueSize; }
@@ -85,6 +87,7 @@ class TenantConfig
     std::string otelExporterType;
     std::string otelExporterEndpoint;
     std::string otelExporterOtlpHeaders;
+    std::string otelExporterOtlpProtocol;
     bool otelSslEnabled;
     std::string otelSslCertPath;
     std::string otelPropagatorType;
@@ -110,6 +113,7 @@ inline std::ostream& operator<< (std::ostream &os, const otel::core::TenantConfi
         << "\n OtelLibraryVersion               " << config.getOtelLibraryVersion()
         << "\n OtelExporterType                 " << config.getOtelExporterType()
         << "\n OtelExporterEndpoint             " << config.getOtelExporterEndpoint()
+        << "\n OtelExporterOtlpProtocol         " << config.getOtelExporterOtlpProtocol()
         << "\n OtelProcessorType                " << config.getOtelProcessorType()
         << "\n OtelPropagatorType               " << config.getOtelPropagatorType()
         << "\n OtelSamplerType                  " << config.getOtelSamplerType()

instrumentation/otel-webserver-module/opentelemetry_module.conf

@@ -4,6 +4,8 @@ LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_trace.so
 LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_otlp_recordable.so
 LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_exporter_ostream_span.so
 LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_exporter_otlp_grpc.so
+LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_exporter_otlp_http.so
+LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_http_client_curl.so
 
 #Load the ApacheModule SDK
 LoadFile /opt/opentelemetry-webserver-sdk/sdk_lib/lib/libopentelemetry_webserver_sdk.so
@@ -14,6 +16,7 @@ ApacheModuleEnabled ON
 #ApacheModule Otel Exporter details
 ApacheModuleOtelSpanExporter otlp
 ApacheModuleOtelExporterEndpoint collector:4317
+#ApacheModuleOtelExporterOtlpProtocol http/protobuf
 #ApacheModuleOtelExporterHeaders api-key=abc123
 
 # SSL Certificates

instrumentation/otel-webserver-module/src/apache/ApacheConfig.cpp

@@ -129,6 +129,14 @@ const char* ApacheConfigHandlers::otel_set_otelExporterOtlpHeaders(cmd_parms *cm
     return helperChar(cmd, cfg, arg, cfg->otelExporterOtlpHeaders, cfg->otelExporterOtlpHeaders_initialized, "otel_set_otelExporterOtlpHeaders");
 }
 
+//  char *otelExporterOtlpProtocol;
+//  int otelExporterOtlpProtocol_initialized;
+const char* ApacheConfigHandlers::otel_set_otelExporterOtlpProtocol(cmd_parms *cmd, void *conf, const char *arg)
+{
+    otel_cfg* cfg = (otel_cfg*) conf;
+    return helperChar(cmd, cfg, arg, cfg->otelExporterOtlpProtocol, cfg->otelExporterOtlpProtocol_initialized, "otel_set_otelExporterOtlpProtocol");
+}
+
 //  char *otelSslEnabled;
 //  int otelSslEnabled_initialized;
 const char* ApacheConfigHandlers::otel_set_otelSslEnabled(cmd_parms *cmd, void *conf, const char *arg)
@@ -444,6 +452,10 @@ void otel_cfg::init()
     otelExporterOtlpHeaders = "";
     otelExporterOtlpHeaders_initialized = 0;
 
+    // otelExporterOtlpProtocol         Optional: OTLP export protocol: grpc, http/protobuf, http/json
+    otelExporterOtlpProtocol = "";
+    otelExporterOtlpProtocol_initialized = 0;
+
     // otelSslEnabled       OPTIONAL: Decides whether the connection to the endpoint is secured
     otelSslEnabled = 0;
     otelSslEnabled_initialized = 0;
@@ -657,6 +669,11 @@ void* ApacheConfigHandlers::otel_merge_dir_config(apr_pool_t* p, void* parent_co
             apr_pstrdup(p, nconf->otelSslCertificatePath) : apr_pstrdup(p, pconf->otelSslCertificatePath);
     merged_config->otelSslCertificatePath_initialized = 1;
 
+    // otelExporterOtlpProtocol          OPTIONAL: OTLP export protocol: grpc, http/protobuf, http/json
+    merged_config->otelExporterOtlpProtocol = nconf->otelExporterOtlpProtocol_initialized ?
+            apr_pstrdup(p, nconf->otelExporterOtlpProtocol) : apr_pstrdup(p, pconf->otelExporterOtlpProtocol);
+    merged_config->otelExporterOtlpProtocol_initialized = 1;
+
     // otelExporterType          OPTIONAL: Type of exporter to be configured in TracerProvider of OTel SDK embedded into Agent
     merged_config->otelExporterType = nconf->otelExporterType_initialized ?
             apr_pstrdup(p, nconf->otelExporterType) : apr_pstrdup(p, pconf->otelExporterType);
@@ -786,6 +803,9 @@ otel_cfg* ApacheConfigHandlers::getProcessConfig(const request_rec* r)
     process_cfg->otelExporterOtlpHeaders = apr_pstrdup(r->server->process->pool, our_config->otelExporterOtlpHeaders);
     process_cfg->otelExporterOtlpHeaders_initialized = our_config->otelExporterOtlpHeaders_initialized;
 
+    process_cfg->otelExporterOtlpProtocol = apr_pstrdup(r->server->process->pool, our_config->otelExporterOtlpProtocol);
+    process_cfg->otelExporterOtlpProtocol_initialized = our_config->otelExporterOtlpProtocol_initialized;
+
     process_cfg->otelSslEnabled = our_config->otelSslEnabled;
     process_cfg->otelSslEnabled_initialized = our_config->otelSslEnabled_initialized;
 

instrumentation/otel-webserver-module/src/apache/ApacheHooks.cpp

@@ -426,11 +426,16 @@ bool ApacheHooks::initialize_opentelemetry(const request_rec *r)
         env_config[ix].value = our_config->getSegmentParameter();
         ++ix;
 
-        // Segment Parameter
+        // OTLP Headers
         env_config[ix].name = OTEL_SDK_ENV_OTEL_EXPORTER_OTLPHEADERS;
         env_config[ix].value = our_config->getOtelExporterOtlpHeaders();
         ++ix;
 
+        // OTLP Protocol
+        env_config[ix].name = OTEL_SDK_ENV_OTEL_EXPORTER_OTLP_PROTOCOL;
+        env_config[ix].value = our_config->getOtelExporterOtlpProtocol();
+        ++ix;
+
         // !!!
         // Remember to update the apr_pcalloc call size if we add another parameter to the input array!
         // !!!

instrumentation/otel-webserver-module/src/apache/mod_apache_otel.cpp

@@ -70,6 +70,12 @@ static const command_rec otel_cmds[] =
             NULL,
             OR_ALL,
             "AppDynamics Otel export Headers key value pairs"),
+    AP_INIT_TAKE1(
+            "apacheModuleOtelExporterOtlpProtocol",
+            (CMD_HAND_TYPE)ApacheConfigHandlers::otel_set_otelExporterOtlpProtocol,
+            NULL,
+            OR_ALL,
+            "OTLP export protocol: grpc, http/protobuf, or http/json (default: http/protobuf)"),
     AP_INIT_TAKE1(
             "apacheModuleOtelSslEnabled",
             (CMD_HAND_TYPE)ApacheConfigHandlers::otel_set_otelSslEnabled,

instrumentation/otel-webserver-module/src/build.gyp

@@ -55,6 +55,8 @@
           '$(ANSDK_DIR)/opentelemetry/$(CPP_SDK_VERSION)/lib/libopentelemetry_otlp_recordable.so',
           '$(ANSDK_DIR)/opentelemetry/$(CPP_SDK_VERSION)/lib/libopentelemetry_exporter_ostream_span.so',
           '$(ANSDK_DIR)/opentelemetry/$(CPP_SDK_VERSION)/lib/libopentelemetry_exporter_otlp_grpc.so',
+          '$(ANSDK_DIR)/opentelemetry/$(CPP_SDK_VERSION)/lib/libopentelemetry_exporter_otlp_http.so',
+          '$(ANSDK_DIR)/opentelemetry/$(CPP_SDK_VERSION)/lib/libopentelemetry_http_client_curl.so',
           '$(BOOST_LIB)',
           '$(LINKER_FLAGS)',
           '$(LIBRARY_FLAGS)',

instrumentation/otel-webserver-module/src/core/api/ApiUtils.cpp

@@ -168,6 +168,7 @@ OTEL_SDK_STATUS_CODE ApiUtils::ReadSettingsFromReader(
     std::string otelExporterType;
     std::string otelExporterEndpoint;
     std::string otelExporterOtlpHeaders;
+    std::string otelExporterOtlpProtocol;
     bool otelSslEnabled;
     std::string otelSslCertPath;
     std::string otelLibraryName;
@@ -263,13 +264,27 @@ OTEL_SDK_STATUS_CODE ApiUtils::ReadSettingsFromReader(
     reader.ReadOptional(
             std::string(OTEL_SDK_ENV_OTEL_EXPORTER_OTLPHEADERS), otelExporterOtlpHeaders);
 
+    reader.ReadOptional(
+            std::string(OTEL_SDK_ENV_OTEL_EXPORTER_OTLP_PROTOCOL), otelExporterOtlpProtocol);
+
+    // Fall back to standard OTel environment variable if not set via module config
+    if (otelExporterOtlpProtocol.empty()) {
+        char* envProtocol = getenv("OTEL_EXPORTER_OTLP_TRACES_PROTOCOL");
+        if (!envProtocol) {
+            envProtocol = getenv("OTEL_EXPORTER_OTLP_PROTOCOL");
+        }
+        if (envProtocol) {
+            otelExporterOtlpProtocol = envProtocol;
+        }
+    }
 
     tenantConfig.setServiceNamespace(serviceNamespace);
     tenantConfig.setServiceName(serviceName);
     tenantConfig.setServiceInstanceId(serviceInstanceId);
     tenantConfig.setOtelExporterType(otelExporterType);
     tenantConfig.setOtelExporterEndpoint(otelExporterEndpoint);
     tenantConfig.setOtelExporterOtlpHeaders(otelExporterOtlpHeaders);
+    tenantConfig.setOtelExporterOtlpProtocol(otelExporterOtlpProtocol);
     tenantConfig.setOtelLibraryName(otelLibraryName);
     tenantConfig.setOtelProcessorType(otelProcessorType);
     tenantConfig.setOtelPropagatorType(otelPropagatorType);