Simplify enum -> str with strum (#2164)

## Issue Addressed

NA

## Proposed Changes

As per #2100, uses derives from the sturm library to implement AsRef<str> and AsStaticRef to easily get str values from enums without creating new Strings. Furthermore unifies all attestation error counter into one IntCounterVec vector.

These works are originally by @blacktemplar, I've just created this PR so I can resolve some merge conflicts.

## Additional Info

NA


Co-authored-by: blacktemplar <blacktemplar@a1.net>

beacon_node/eth2_libp2p/src/peer_manager/client.rs

@@ -4,6 +4,7 @@
 
 use libp2p::identify::IdentifyInfo;
 use serde::Serialize;
+use strum::{AsRefStr, AsStaticStr};
 
 /// Various client and protocol information related to a node.
 #[derive(Clone, Debug, Serialize)]
@@ -20,7 +21,7 @@ pub struct Client {
     pub agent_string: Option<String>,
 }
 
-#[derive(Clone, Debug, Serialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, PartialEq, AsRefStr, AsStaticStr)]
 pub enum ClientKind {
     /// A lighthouse node (the best kind).
     Lighthouse,
@@ -98,26 +99,6 @@ impl std::fmt::Display for Client {
     }
 }
 
-impl ClientKind {
-    pub fn as_static_ref(&self) -> &'static str {
-        use ClientKind::*;
-        match self {
-            Lighthouse => "Lighthouse",
-            Nimbus => "Nimbus",
-            Teku => "Teku",
-            Prysm => "Prysm",
-            Lodestar => "Lodestar",
-            Unknown => "Unknown",
-        }
-    }
-}
-
-impl AsRef<str> for ClientKind {
-    fn as_ref(&self) -> &str {
-        self.as_static_ref()
-    }
-}
-
 impl std::fmt::Display for ClientKind {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.write_str(self.as_ref())

beacon_node/eth2_libp2p/src/peer_manager/mod.rs

@@ -158,8 +158,8 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
             metrics::inc_counter_vec(
                 &metrics::PEER_ACTION_EVENTS_PER_CLIENT,
                 &[
-                    info.client.kind.as_static_ref(),
-                    PeerAction::Fatal.as_static_str(),
+                    info.client.kind.as_ref(),
+                    PeerAction::Fatal.as_ref(),
                     source.into(),
                 ],
             );
@@ -193,11 +193,7 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
                 info.apply_peer_action_to_score(action);
                 metrics::inc_counter_vec(
                     &metrics::PEER_ACTION_EVENTS_PER_CLIENT,
-                    &[
-                        info.client.kind.as_static_ref(),
-                        action.as_static_str(),
-                        source.into(),
-                    ],
+                    &[info.client.kind.as_ref(), action.as_ref(), source.into()],
                 );
 
                 Self::handle_score_transitions(
@@ -407,9 +403,9 @@ impl<TSpec: EthSpec> PeerManager<TSpec> {
         metrics::inc_counter_vec(
             &metrics::TOTAL_RPC_ERRORS_PER_CLIENT,
             &[
-                client.kind.as_static_ref(),
+                client.kind.as_ref(),
                 err.as_static_str(),
-                direction.as_static_str(),
+                direction.as_ref(),
             ],
         );
 

beacon_node/eth2_libp2p/src/peer_manager/peer_info.rs

@@ -11,6 +11,7 @@ use serde::{
 use std::collections::HashSet;
 use std::net::{IpAddr, SocketAddr};
 use std::time::Instant;
+use strum::AsRefStr;
 use types::{EthSpec, SubnetId};
 use PeerConnectionStatus::*;
 
@@ -320,21 +321,13 @@ impl Default for PeerStatus {
 }
 
 /// Connection Direction of connection.
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, AsRefStr)]
+#[strum(serialize_all = "snake_case")]
 pub enum ConnectionDirection {
     Incoming,
     Outgoing,
 }
 
-impl ConnectionDirection {
-    pub fn as_static_str(&self) -> &'static str {
-        match self {
-            ConnectionDirection::Incoming => "incoming",
-            ConnectionDirection::Outgoing => "outgoing",
-        }
-    }
-}
-
 /// Connection Status of the peer.
 #[derive(Debug, Clone)]
 pub enum PeerConnectionStatus {

beacon_node/eth2_libp2p/src/peer_manager/score.rs

@@ -8,6 +8,7 @@
 use crate::behaviour::GOSSIPSUB_GREYLIST_THRESHOLD;
 use serde::Serialize;
 use std::time::Instant;
+use strum::AsRefStr;
 use tokio::time::Duration;
 
 lazy_static! {
@@ -42,7 +43,8 @@ const GOSSIPSUB_POSITIVE_SCORE_WEIGHT: f64 = GOSSIPSUB_NEGATIVE_SCORE_WEIGHT;
 /// Each variant has an associated score change.
 // To easily assess the behaviour of scores changes the number of variants should stay low, and
 // somewhat generic.
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, AsRefStr)]
+#[strum(serialize_all = "snake_case")]
 pub enum PeerAction {
     /// We should not communicate more with this peer.
     /// This action will cause the peer to get banned.
@@ -94,17 +96,6 @@ impl std::fmt::Display for PeerAction {
     }
 }
 
-impl PeerAction {
-    pub fn as_static_str(&self) -> &'static str {
-        match self {
-            PeerAction::HighToleranceError => "high_tolerance",
-            PeerAction::MidToleranceError => "mid_tolerance",
-            PeerAction::LowToleranceError => "low_tolerance",
-            PeerAction::Fatal => "fatal",
-        }
-    }
-}
-
 /// The expected state of the peer given the peer's score.
 #[derive(Debug, PartialEq, Clone, Copy)]
 pub(crate) enum ScoreState {