customize brpc metrics path

src/brpc/builtin/prometheus_metrics_service.cpp

@@ -32,6 +32,9 @@ DECLARE_int32(bvar_latency_p3);
 
 namespace brpc {
 
+DEFINE_string(prometheus_metrics_path, "/metrics", "The HTTP resource "
+        "path from which prometheus fetch metrics.");
+
 // This is a class that convert bvar result to prometheus output.
 // Currently the output only includes gauge and summary for two
 // reasons:
@@ -174,10 +177,10 @@ bool PrometheusMetricsDumper::DumpLatencyRecorderSuffix(
     return true;
 }
 
-void PrometheusMetricsService::default_method(::google::protobuf::RpcController* cntl_base,
-                                              const ::brpc::MetricsRequest*,
-                                              ::brpc::MetricsResponse*,
-                                              ::google::protobuf::Closure* done) {
+void PrometheusMetricsService::metrics(::google::protobuf::RpcController* cntl_base,
+                                       const ::brpc::MetricsRequest*,
+                                       ::brpc::MetricsResponse*,
+                                       ::google::protobuf::Closure* done) {
     ClosureGuard done_guard(done);
     Controller *cntl = static_cast<Controller*>(cntl_base);
     cntl->http_response().set_content_type("text/plain");

src/brpc/builtin/prometheus_metrics_service.h

@@ -22,15 +22,15 @@
 
 namespace brpc {
 
-class PrometheusMetricsService : public brpc_vars_metrics {
+class PrometheusMetricsService : public bvars {
 public:
     PrometheusMetricsService(Server* server)
         : _server(server) {}
 
-    void default_method(::google::protobuf::RpcController* cntl_base,
-                        const ::brpc::MetricsRequest* request,
-                        ::brpc::MetricsResponse* response,
-                        ::google::protobuf::Closure* done) override;
+    void metrics(::google::protobuf::RpcController* cntl_base,
+                 const ::brpc::MetricsRequest* request,
+                 ::brpc::MetricsResponse* response,
+                 ::google::protobuf::Closure* done) override;
 private:
     Server* _server;
 };

src/brpc/builtin_service.proto

@@ -97,8 +97,8 @@ service sockets {
     rpc default_method(SocketsRequest) returns (SocketsResponse);
 }
 
-service brpc_vars_metrics {
-    rpc default_method(MetricsRequest) returns (MetricsResponse);
+service bvars {
+    rpc metrics(MetricsRequest) returns (MetricsResponse);
 }
 
 service badmethod {

src/brpc/server.cpp

@@ -110,6 +110,7 @@ DEFINE_bool(enable_threads_service, false, "Enable /threads");
 
 DECLARE_int32(usercode_backup_threads);
 DECLARE_bool(usercode_in_pthread);
+DECLARE_string(prometheus_metrics_path);
 
 const int INITIAL_SERVICE_CAP = 64;
 const int INITIAL_CERT_MAP = 64;
@@ -484,7 +485,10 @@ int Server::AddBuiltinServices() {
         LOG(ERROR) << "Fail to add ListService";
         return -1;
     }
-    if (AddBuiltinService(new (std::nothrow) PrometheusMetricsService(this))) {
+    ServiceOptions options;
+    options.ownership = SERVER_OWNS_SERVICE;
+    options.restful_mappings = FLAGS_prometheus_metrics_path + " => metrics";
+    if (AddBuiltinService(new (std::nothrow) PrometheusMetricsService(this), options)) {
         LOG(ERROR) << "Fail to add MetricsService";
         return -1;
     }
@@ -1411,6 +1415,11 @@ int Server::AddService(google::protobuf::Service* service,
 int Server::AddBuiltinService(google::protobuf::Service* service) {
     ServiceOptions options;
     options.ownership = SERVER_OWNS_SERVICE;
+    return AddBuiltinService(service, options);
+}
+
+int Server::AddBuiltinService(google::protobuf::Service* service,
+                              const ServiceOptions& options) {
     return AddServiceInternal(service, true, options);
 }
 

src/brpc/server.h

@@ -530,6 +530,8 @@ friend class Controller;
                            const ServiceOptions& options);
 
     int AddBuiltinService(google::protobuf::Service* service);
+    int AddBuiltinService(google::protobuf::Service* service,
+                          const ServiceOptions& options);
 
     // Remove all methods of `service' from internal structures.
     void RemoveMethodsOf(google::protobuf::Service* service);

test/brpc_prometheus_metrics_unittest.cpp

@@ -10,6 +10,10 @@
 #include "butil/strings/string_piece.h"
 #include "echo.pb.h"
 
+namespace brpc {
+DECLARE_string(prometheus_metrics_path);
+} // brpc
+
 int main(int argc, char* argv[]) {
     testing::InitGoogleTest(&argc, argv);
     return RUN_ALL_TESTS();
@@ -45,7 +49,7 @@ TEST(PrometheusMetrics, sanity) {
     channel_opts.protocol = "http";
     ASSERT_EQ(0, channel.Init("127.0.0.1:8614", &channel_opts));
     brpc::Controller cntl;
-    cntl.http_request().uri() = "/brpc_vars_metrics";
+    cntl.http_request().uri() = brpc::FLAGS_prometheus_metrics_path;
     channel.CallMethod(NULL, &cntl, NULL, NULL, NULL);
     ASSERT_FALSE(cntl.Failed());
     std::string res = cntl.response_attachment().to_string();