chore: expose grpc request entrypoint

crates/topos-metrics/src/api.rs

@@ -0,0 +1,15 @@
+use prometheus::{self, register_int_counter_with_registry, IntCounter};
+
+use lazy_static::lazy_static;
+
+use crate::TOPOS_METRIC_REGISTRY;
+
+lazy_static! {
+    pub static ref API_GRPC_CERTIFICATE_RECEIVED_TOTAL: IntCounter =
+        register_int_counter_with_registry!(
+            "api_grpc_certificate_received_total",
+            "Number of Certificates received from the gRPC API.",
+            TOPOS_METRIC_REGISTRY
+        )
+        .unwrap();
+}

crates/topos-metrics/src/lib.rs

@@ -5,10 +5,12 @@ use prometheus::{
 
 use lazy_static::lazy_static;
 
+mod api;
 mod double_echo;
 mod p2p;
 mod storage;
 
+pub use api::*;
 pub use double_echo::*;
 pub use p2p::*;
 pub use storage::*;

crates/topos-tce-api/src/grpc/mod.rs

@@ -12,6 +12,7 @@ use topos_core::api::grpc::tce::v1::{
 };
 use topos_core::api::grpc::uci::v1::OptionalCertificate;
 use topos_core::uci::SubnetId;
+use topos_metrics::API_GRPC_CERTIFICATE_RECEIVED_TOTAL;
 use tracing::{error, info, Span};
 use uuid::Uuid;
 
@@ -106,6 +107,8 @@ impl ApiService for TceGrpcService {
                         .is_err()
                     {
                         return Err(Status::internal("Can't submit certificate: sender dropped"));
+                    } else {
+                        API_GRPC_CERTIFICATE_RECEIVED_TOTAL.inc();
                     }
 
                     receiver

crates/topos-tce-api/src/metrics/mod.rs

@@ -1 +1,2 @@
 pub(crate) mod builder;
+