Add global metrics registry, pass to BeaconState

beacon_node/http_server/src/key.rs

@@ -1,5 +1,6 @@
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use iron::typemap::Key;
+use prometheus::Registry;
 use std::marker::PhantomData;
 use std::sync::Arc;
 
@@ -10,3 +11,9 @@ pub struct BeaconChainKey<T> {
 impl<T: BeaconChainTypes + 'static> Key for BeaconChainKey<T> {
     type Value = Arc<BeaconChain<T>>;
 }
+
+pub struct MetricsRegistryKey;
+
+impl Key for MetricsRegistryKey {
+    type Value = Registry;
+}

beacon_node/http_server/src/lib.rs

@@ -6,6 +6,7 @@ use beacon_chain::{BeaconChain, BeaconChainTypes};
 use futures::Future;
 use iron::prelude::*;
 use network::NetworkMessage;
+use prometheus::Registry;
 use router::Router;
 use slog::{info, o, warn};
 use std::sync::Arc;
@@ -31,13 +32,14 @@ impl Default for HttpServerConfig {
 /// Build the `iron` HTTP server, defining the core routes.
 pub fn create_iron_http_server<T: BeaconChainTypes + 'static>(
     beacon_chain: Arc<BeaconChain<T>>,
+    metrics_registry: Registry,
 ) -> Iron<Router> {
     let mut router = Router::new();
 
     // A `GET` request to `/metrics` is handled by the `metrics` module.
     router.get(
         "/metrics",
-        metrics::build_handler(beacon_chain.clone()),
+        metrics::build_handler(beacon_chain.clone(), metrics_registry),
         "metrics",
     );
 
@@ -53,6 +55,7 @@ pub fn start_service<T: BeaconChainTypes + 'static>(
     executor: &TaskExecutor,
     _network_chan: crossbeam_channel::Sender<NetworkMessage>,
     beacon_chain: Arc<BeaconChain<T>>,
+    metrics_registry: Registry,
     log: &slog::Logger,
 ) -> exit_future::Signal {
     let log = log.new(o!("Service"=>"HTTP"));
@@ -63,7 +66,7 @@ pub fn start_service<T: BeaconChainTypes + 'static>(
     let (shutdown_trigger, wait_for_shutdown) = exit_future::signal();
 
     // Create an `iron` http, without starting it yet.
-    let iron = create_iron_http_server(beacon_chain);
+    let iron = create_iron_http_server(beacon_chain, metrics_registry);
 
     // Create a HTTP server future.
     //

beacon_node/http_server/src/metrics.rs

@@ -1,4 +1,7 @@
-use crate::{key::BeaconChainKey, map_persistent_err_to_500};
+use crate::{
+    key::{BeaconChainKey, MetricsRegistryKey},
+    map_persistent_err_to_500,
+};
 use beacon_chain::{BeaconChain, BeaconChainTypes};
 use iron::prelude::*;
 use iron::{status::Status, Handler, IronResult, Request, Response};
@@ -11,10 +14,12 @@ use types::Slot;
 /// Yields a handler for the metrics endpoint.
 pub fn build_handler<T: BeaconChainTypes + 'static>(
     beacon_chain: Arc<BeaconChain<T>>,
+    metrics_registry: Registry,
 ) -> impl Handler {
     let mut chain = Chain::new(handle_metrics::<T>);
 
     chain.link(Read::<BeaconChainKey<T>>::both(beacon_chain));
+    chain.link(Read::<MetricsRegistryKey>::both(metrics_registry));
 
     chain
 }
@@ -27,7 +32,9 @@ fn handle_metrics<T: BeaconChainTypes + 'static>(req: &mut Request) -> IronResul
         .get::<Read<BeaconChainKey<T>>>()
         .map_err(map_persistent_err_to_500)?;
 
-    let r = Registry::new();
+    let r = req
+        .get::<Read<MetricsRegistryKey>>()
+        .map_err(map_persistent_err_to_500)?;
 
     let present_slot = beacon_chain
         .slot_clock