libp2p · mergify · Jan 3, 2023 · Dec 7, 2022 · Dec 9, 2022 · Dec 14, 2022
diff --git a/misc/metrics/CHANGELOG.md b/misc/metrics/CHANGELOG.md
@@ -1,11 +1,13 @@
 # 0.12.0 [unreleased]
 
-- Update to `libp2p-core` `v0.39.0`.
+- Update to `prometheus-client` `v0.19.0`. See [PR 3207].
 
 - Add `connections_establishment_duration` metric. See [PR 3134].
 
 - Bump MSRV to 1.65.0.
 
+- Update to `libp2p-core` `v0.39.0`.
+
 - Update to `libp2p-dcutr` `v0.9.0`.
 
 - Update to `libp2p-ping` `v0.42.0`.
@@ -19,6 +21,7 @@
 - Update to `libp2p-swarm` `v0.42.0`.
 
 [PR 3134]: https://github.com/libp2p/rust-libp2p/pull/3134/
+[PR 3207]: https://github.com/libp2p/rust-libp2p/pull/3207/
 
 # 0.11.0
 

diff --git a/misc/metrics/Cargo.toml b/misc/metrics/Cargo.toml
@@ -26,7 +26,7 @@ libp2p-kad = { version = "0.43.0", path = "../../protocols/kad", optional = true
 libp2p-ping = { version = "0.42.0", path = "../../protocols/ping", optional = true }
 libp2p-relay =  { version = "0.15.0", path = "../../protocols/relay", optional = true }
 libp2p-swarm = { version = "0.42.0", path = "../../swarm" }
-prometheus-client = "0.18.0"
+prometheus-client = "0.19.0"
 
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
 libp2p-gossipsub =  { version = "0.44.0", path = "../../protocols/gossipsub", optional = true }
@@ -52,4 +52,4 @@ rustc-args = ["--cfg", "docsrs"]
 
 [[example]]
 name = "metrics"
-required-features = ["ping"]
+required-features = ["ping", "identify"]
diff --git a/misc/metrics/examples/metrics/http_service.rs b/misc/metrics/examples/metrics/http_service.rs
@@ -29,6 +29,8 @@ use std::pin::Pin;
 use std::sync::{Arc, Mutex};
 use std::task::{Context, Poll};
 
+const METRICS_CONTENT_TYPE: &str = "application/openmetrics-text;charset=utf-8;version=1.0.0";
+
 pub async fn metrics_server(registry: Registry) -> Result<(), std::io::Error> {
     // Serve on localhost.
     let addr = ([127, 0, 0, 1], 0).into();
@@ -55,27 +57,31 @@ impl MetricService {
     fn get_reg(&mut self) -> SharedRegistry {
         Arc::clone(&self.reg)
     }
-    fn respond_with_metrics(&mut self) -> Response<Body> {
-        let mut encoded: Vec<u8> = Vec::new();
+    fn respond_with_metrics(&mut self) -> Response<String> {
+        let mut response: Response<String> = Response::default();
+
+        response.headers_mut().insert(
+            hyper::header::CONTENT_TYPE,
+            METRICS_CONTENT_TYPE.try_into().unwrap(),
+        );
+
         let reg = self.get_reg();
-        encode(&mut encoded, &reg.lock().unwrap()).unwrap();
-        let metrics_content_type = "application/openmetrics-text;charset=utf-8;version=1.0.0";
-        Response::builder()
-            .status(StatusCode::OK)
-            .header(hyper::header::CONTENT_TYPE, metrics_content_type)
-            .body(Body::from(encoded))
-            .unwrap()
+        encode(&mut response.body_mut(), &reg.lock().unwrap()).unwrap();
+
+        *response.status_mut() = StatusCode::OK;
+
+        response
     }
-    fn respond_with_404_not_found(&mut self) -> Response<Body> {
+    fn respond_with_404_not_found(&mut self) -> Response<String> {
         Response::builder()
             .status(StatusCode::NOT_FOUND)
-            .body(Body::from("Not found try localhost:[port]/metrics"))
+            .body("Not found try localhost:[port]/metrics".to_string())
             .unwrap()
     }
 }
 
 impl Service<Request<Body>> for MetricService {
-    type Response = Response<Body>;
+    type Response = Response<String>;
     type Error = hyper::Error;
     type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
 

diff --git a/misc/metrics/src/dcutr.rs b/misc/metrics/src/dcutr.rs
@@ -18,7 +18,7 @@
 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 // DEALINGS IN THE SOFTWARE.
 
-use prometheus_client::encoding::text::Encode;
+use prometheus_client::encoding::{EncodeLabelSet, EncodeLabelValue};
 use prometheus_client::metrics::counter::Counter;
 use prometheus_client::metrics::family::Family;
 use prometheus_client::registry::Registry;
@@ -35,19 +35,19 @@ impl Metrics {
         sub_registry.register(
             "events",
             "Events emitted by the relay NetworkBehaviour",
-            Box::new(events.clone()),
+            events.clone(),
         );
 
         Self { events }
     }
 }
 
-#[derive(Debug, Clone, Hash, PartialEq, Eq, Encode)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq, EncodeLabelSet)]
 struct EventLabels {
     event: EventType,
 }
 
-#[derive(Debug, Clone, Hash, PartialEq, Eq, Encode)]
+#[derive(Debug, Clone, Hash, PartialEq, Eq, EncodeLabelValue)]
 enum EventType {
     InitiateDirectConnectionUpgrade,
     RemoteInitiatedDirectConnectionUpgrade,

diff --git a/misc/metrics/src/gossipsub.rs b/misc/metrics/src/gossipsub.rs
@@ -30,11 +30,7 @@ impl Metrics {
         let sub_registry = registry.sub_registry_with_prefix("gossipsub");
 
         let messages = Counter::default();
-        sub_registry.register(
-            "messages",
-            "Number of messages received",
-            Box::new(messages.clone()),
-        );
+        sub_registry.register("messages", "Number of messages received", messages.clone());
 
         Self { messages }
     }

diff --git a/misc/metrics/src/identify.rs b/misc/metrics/src/identify.rs
@@ -20,7 +20,7 @@
 
 use crate::protocol_stack;
 use libp2p_core::PeerId;
-use prometheus_client::encoding::text::{Encode, EncodeMetric, Encoder};
+use prometheus_client::encoding::{EncodeLabelSet, EncodeMetric, MetricEncoder};
 use prometheus_client::metrics::counter::Counter;
 use prometheus_client::metrics::family::Family;
 use prometheus_client::metrics::histogram::{exponential_buckets, Histogram};
@@ -51,30 +51,30 @@ impl Metrics {
             "Number of connected nodes supporting a specific protocol, with \
              \"unrecognized\" for each peer supporting one or more unrecognized \
              protocols",
-            Box::new(protocols.clone()),
+            protocols.clone(),
         );
 
         let error = Counter::default();
         sub_registry.register(
             "errors",
             "Number of errors while attempting to identify the remote",
-            Box::new(error.clone()),
+            error.clone(),
         );
 
         let pushed = Counter::default();
         sub_registry.register(
             "pushed",
             "Number of times identification information of the local node has \
              been actively pushed to a peer.",
-            Box::new(pushed.clone()),
+            pushed.clone(),
         );
 
         let received = Counter::default();
         sub_registry.register(
             "received",
             "Number of times identification information has been received from \
              a peer",
-            Box::new(received.clone()),
+            received.clone(),
         );
 
         let received_info_listen_addrs =
@@ -83,7 +83,7 @@ impl Metrics {
             "received_info_listen_addrs",
             "Number of listen addresses for remote peer received in \
              identification information",
-            Box::new(received_info_listen_addrs.clone()),
+            received_info_listen_addrs.clone(),
         );
 
         let received_info_protocols =
@@ -92,22 +92,22 @@ impl Metrics {
             "received_info_protocols",
             "Number of protocols supported by the remote peer received in \
              identification information",
-            Box::new(received_info_protocols.clone()),
+            received_info_protocols.clone(),
         );
 
         let sent = Counter::default();
         sub_registry.register(
             "sent",
             "Number of times identification information of the local node has \
              been sent to a peer in response to an identification request",
-            Box::new(sent.clone()),
+            sent.clone(),
         );
 
         let listen_addresses = Family::default();
         sub_registry.register(
             "listen_addresses",
             "Number of listen addresses for remote peer per protocol stack",
-            Box::new(listen_addresses.clone()),
+            listen_addresses.clone(),
         );
 
         Self {
@@ -208,12 +208,12 @@ impl<TBvEv, THandleErr> super::Recorder<libp2p_swarm::SwarmEvent<TBvEv, THandleE
     }
 }
 
-#[derive(Encode, Hash, Clone, Eq, PartialEq)]
+#[derive(EncodeLabelSet, Hash, Clone, Eq, PartialEq, Debug)]
 struct AddressLabels {
     protocols: String,
 }
 
-#[derive(Default, Clone)]
+#[derive(Default, Clone, Debug)]
 struct Protocols {
     peers: Arc<Mutex<HashMap<PeerId, Vec<String>>>>,
 }
@@ -235,14 +235,14 @@ impl Protocols {
 }
 
 impl EncodeMetric for Protocols {
-    fn encode(&self, mut encoder: Encoder) -> Result<(), std::io::Error> {
+    fn encode(&self, mut encoder: MetricEncoder) -> Result<(), std::fmt::Error> {
         let count_by_protocol = self
             .peers
             .lock()
             .expect("Lock not to be poisoned")
             .iter()
             .fold(
-                HashMap::<String, u64>::default(),
+                HashMap::<String, i64>::default(),
                 |mut acc, (_, protocols)| {
                     for protocol in protocols {
                         let count = acc.entry(protocol.to_string()).or_default();
@@ -254,11 +254,8 @@ impl EncodeMetric for Protocols {
 
         for (protocol, count) in count_by_protocol {
             encoder
-                .with_label_set(&("protocol", protocol))
-                .no_suffix()?
-                .no_bucket()?
-                .encode_value(count)?
-                .no_exemplar()?;
+                .encode_family(&[("protocol", protocol)])?
+                .encode_gauge(&count)?;
         }
 
         Ok(())