Node endpoints (#1778)

## Issue Addressed

`node` endpoints in #1434

## Proposed Changes

Implement these:
```
 /eth/v1/node/health
 /eth/v1/node/peers/{peer_id}
 /eth/v1/node/peers
```
- Add an `Option<Enr>` to `PeerInfo`
- Finish implementation of `/eth/v1/node/identity`

## Additional Info
- should update the `peers` endpoints when #1764 is resolved



Co-authored-by: realbigsean <seananderson33@gmail.com>

beacon_node/eth2_libp2p/src/discovery/enr_ext.rs

@@ -13,9 +13,15 @@ pub trait EnrExt {
     /// The vector remains empty if these fields are not defined.
     fn multiaddr(&self) -> Vec<Multiaddr>;
 
-    /// Returns the multiaddr with the `PeerId` prepended.
+    /// Returns a list of multiaddrs with the `PeerId` prepended.
     fn multiaddr_p2p(&self) -> Vec<Multiaddr>;
 
+    /// Returns any multiaddrs that contain the TCP protocol with the `PeerId` prepended.
+    fn multiaddr_p2p_tcp(&self) -> Vec<Multiaddr>;
+
+    /// Returns any multiaddrs that contain the UDP protocol with the `PeerId` prepended.
+    fn multiaddr_p2p_udp(&self) -> Vec<Multiaddr>;
+
     /// Returns any multiaddrs that contain the TCP protocol.
     fn multiaddr_tcp(&self) -> Vec<Multiaddr>;
 }
@@ -111,6 +117,58 @@ impl EnrExt for Enr {
         multiaddrs
     }
 
+    /// Returns a list of multiaddrs if the ENR has an `ip` and a `tcp` key **or** an `ip6` and a `tcp6`.
+    /// The vector remains empty if these fields are not defined.
+    ///
+    /// This also prepends the `PeerId` into each multiaddr with the `P2p` protocol.
+    fn multiaddr_p2p_tcp(&self) -> Vec<Multiaddr> {
+        let peer_id = self.peer_id();
+        let mut multiaddrs: Vec<Multiaddr> = Vec::new();
+        if let Some(ip) = self.ip() {
+            if let Some(tcp) = self.tcp() {
+                let mut multiaddr: Multiaddr = ip.into();
+                multiaddr.push(Protocol::Tcp(tcp));
+                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddrs.push(multiaddr);
+            }
+        }
+        if let Some(ip6) = self.ip6() {
+            if let Some(tcp6) = self.tcp6() {
+                let mut multiaddr: Multiaddr = ip6.into();
+                multiaddr.push(Protocol::Tcp(tcp6));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
+                multiaddrs.push(multiaddr);
+            }
+        }
+        multiaddrs
+    }
+
+    /// Returns a list of multiaddrs if the ENR has an `ip` and a `udp` key **or** an `ip6` and a `udp6`.
+    /// The vector remains empty if these fields are not defined.
+    ///
+    /// This also prepends the `PeerId` into each multiaddr with the `P2p` protocol.
+    fn multiaddr_p2p_udp(&self) -> Vec<Multiaddr> {
+        let peer_id = self.peer_id();
+        let mut multiaddrs: Vec<Multiaddr> = Vec::new();
+        if let Some(ip) = self.ip() {
+            if let Some(udp) = self.udp() {
+                let mut multiaddr: Multiaddr = ip.into();
+                multiaddr.push(Protocol::Udp(udp));
+                multiaddr.push(Protocol::P2p(peer_id.clone().into()));
+                multiaddrs.push(multiaddr);
+            }
+        }
+        if let Some(ip6) = self.ip6() {
+            if let Some(udp6) = self.udp6() {
+                let mut multiaddr: Multiaddr = ip6.into();
+                multiaddr.push(Protocol::Udp(udp6));
+                multiaddr.push(Protocol::P2p(peer_id.into()));
+                multiaddrs.push(multiaddr);
+            }
+        }
+        multiaddrs
+    }
+
     /// Returns a list of multiaddrs if the ENR has an `ip` and either a `tcp` or `udp` key **or** an `ip6` and either a `tcp6` or `udp6`.
     /// The vector remains empty if these fields are not defined.
     fn multiaddr_tcp(&self) -> Vec<Multiaddr> {

beacon_node/eth2_libp2p/src/discovery/mod.rs

@@ -5,7 +5,7 @@ pub mod enr_ext;
 // Allow external use of the lighthouse ENR builder
 pub use enr::{build_enr, create_enr_builder_from_config, use_or_load_enr, CombinedKey, Eth2Enr};
 pub use enr_ext::{peer_id_to_node_id, CombinedKeyExt, EnrExt};
-pub use libp2p::core::identity::Keypair;
+pub use libp2p::core::identity::{Keypair, PublicKey};
 
 use crate::metrics;
 use crate::{error, Enr, NetworkConfig, NetworkGlobals, SubnetDiscovery};