miden_node_utils/tracing/
grpc.rs

1use http::header::HeaderName;
2use tower_governor::key_extractor::{KeyExtractor, SmartIpKeyExtractor};
3use tracing::field;
4
5/// Returns a [`trace_fn`](tonic::transport::server::Server) implementation for gRPC requests
6/// which adds open-telemetry information to the span.
7///
8/// Creates an `info` span following the open-telemetry standard: `{service}/{method}`.
9/// The span name is dynamically set using the HTTP path via the `otel.name` field.
10/// Additionally also pulls in remote tracing context which allows the server trace to be connected
11/// to the client's origin trace.
12#[track_caller]
13pub fn grpc_trace_fn<T>(request: &http::Request<T>) -> tracing::Span {
14    // A gRPC request's path ends with `../<service>/<method>`.
15    let mut path_segments = request.uri().path().rsplit('/');
16
17    let method = path_segments.next().unwrap_or_default();
18    let service = path_segments.next().unwrap_or_default();
19
20    // Create a span with a generic, static name. Fields to be recorded after needs to be
21    // initialized as empty since otherwise the assignment will have no effect.
22    let span = tracing::info_span!(
23        "rpc",
24        otel.name = field::Empty,
25        rpc.service = service,
26        rpc.method = method,
27        rpc.system = field::Empty,
28        server.address = field::Empty,
29        server.port = field::Empty,
30        client.address = field::Empty,
31        client.port = field::Empty,
32        network.peer.address = field::Empty,
33        network.peer.port = field::Empty,
34        network.transport = field::Empty,
35        network.type = field::Empty,
36    );
37
38    // Set the span name via otel.name
39    let otel_name = format!("{service}/{method}");
40    span.record("otel.name", otel_name);
41
42    // Pull the open-telemetry parent context using the HTTP extractor
43    let otel_ctx = opentelemetry::global::get_text_map_propagator(|propagator| {
44        propagator.extract(&MetadataExtractor(&tonic::metadata::MetadataMap::from_headers(
45            request.headers().clone(),
46        )))
47    });
48    let _ = tracing_opentelemetry::OpenTelemetrySpanExt::set_parent(&span, otel_ctx);
49
50    // Adds various network attributes to the span, including remote address and port.
51    //
52    // See [server attributes](https://opentelemetry.io/docs/specs/semconv/rpc/rpc-spans/#server-attributes).
53
54    // Set HTTP attributes.
55    span.record("rpc.system", "grpc");
56    if let Some(host) = request.uri().host() {
57        span.record("server.address", host);
58    }
59    if let Some(host_port) = request.uri().port() {
60        span.record("server.port", host_port.as_u16());
61    }
62    let remote_addr = request
63        .extensions()
64        .get::<tonic::transport::server::TcpConnectInfo>()
65        .and_then(tonic::transport::server::TcpConnectInfo::remote_addr);
66
67    // client.address should be the resolved IP address of the client, if available. In the case of
68    // a reverse proxy, this may not be the same as the remote address.
69    if let Ok(ip) = SmartIpKeyExtractor.extract(request) {
70        span.record("client.address", field::display(ip));
71    } else if let Some(addr) = remote_addr {
72        span.record("client.address", field::display(addr.ip()));
73        span.record("client.port", addr.port());
74    }
75
76    if let Some(addr) = remote_addr {
77        span.record("network.peer.address", field::display(addr.ip()));
78        span.record("network.peer.port", addr.port());
79        span.record("network.transport", "tcp");
80        match addr.ip() {
81            std::net::IpAddr::V4(_) => span.record("network.type", "ipv4"),
82            std::net::IpAddr::V6(_) => span.record("network.type", "ipv6"),
83        };
84    }
85
86    for header in [
87        http::header::ACCEPT,
88        http::header::ORIGIN,
89        http::header::USER_AGENT,
90        http::header::FORWARDED,
91        HeaderName::from_static("x-forwarded-for"),
92        HeaderName::from_static("x-real-ip"),
93        HeaderName::from_static("x-request-id"),
94    ] {
95        if let Some(value) = request.headers().get(&header) {
96            if let Ok(value) = value.to_str() {
97                tracing_opentelemetry::OpenTelemetrySpanExt::set_attribute(
98                    &span,
99                    format!("http.request.header.{header}"),
100                    value.to_owned(),
101                );
102            }
103        }
104    }
105
106    span
107}
108
109/// Injects open-telemetry remote context into traces.
110#[derive(Copy, Clone)]
111pub struct OtelInterceptor;
112
113impl tonic::service::Interceptor for OtelInterceptor {
114    fn call(
115        &mut self,
116        mut request: tonic::Request<()>,
117    ) -> Result<tonic::Request<()>, tonic::Status> {
118        use tracing_opentelemetry::OpenTelemetrySpanExt;
119        let ctx = tracing::Span::current().context();
120        opentelemetry::global::get_text_map_propagator(|propagator| {
121            propagator.inject_context(&ctx, &mut MetadataInjector(request.metadata_mut()));
122        });
123
124        Ok(request)
125    }
126}
127
128struct MetadataExtractor<'a>(&'a tonic::metadata::MetadataMap);
129impl opentelemetry::propagation::Extractor for MetadataExtractor<'_> {
130    /// Get a value for a key from the `MetadataMap`.  If the value can't be converted to &str,
131    /// returns None
132    fn get(&self, key: &str) -> Option<&str> {
133        self.0.get(key).and_then(|metadata| metadata.to_str().ok())
134    }
135
136    /// Collect all the keys from the `MetadataMap`.
137    fn keys(&self) -> Vec<&str> {
138        self.0
139            .keys()
140            .map(|key| match key {
141                tonic::metadata::KeyRef::Ascii(v) => v.as_str(),
142                tonic::metadata::KeyRef::Binary(v) => v.as_str(),
143            })
144            .collect::<Vec<_>>()
145    }
146}
147
148struct MetadataInjector<'a>(&'a mut tonic::metadata::MetadataMap);
149impl opentelemetry::propagation::Injector for MetadataInjector<'_> {
150    /// Set a key and value in the `MetadataMap`.  Does nothing if the key or value are not valid
151    /// inputs
152    fn set(&mut self, key: &str, value: String) {
153        if let Ok(key) = tonic::metadata::MetadataKey::from_bytes(key.as_bytes())
154            && let Ok(val) = tonic::metadata::MetadataValue::try_from(&value)
155        {
156            self.0.insert(key, val);
157        }
158    }
159}
miden_node_utils/tracing/grpc.rs

miden_node_utils/tracing/
grpc.rs
