Mh public key for telemetry (#526)

* Expose node public key to telemetry

* unwrap to expect

* Make sure all the zeros are there

* Cleanup

substrate/substrate/service/src/lib.rs

@@ -57,6 +57,7 @@ pub mod chain_ops;
 use std::io;
 use std::net::SocketAddr;
 use std::sync::Arc;
+use std::fmt::Write;
 use futures::prelude::*;
 use keystore::Store as Keystore;
 use client::BlockchainEvents;
@@ -125,10 +126,17 @@ impl<Components> Service<Components>
 			keystore.generate_from_seed(seed)?;
 		}
 
-		if keystore.contents()?.is_empty() {
-			let key = keystore.generate("")?;
-			info!("Generated a new keypair: {:?}", key.public());
-		}
+		// Keep the public key for telemetry
+		let public_key = match keystore.contents()?.get(0) {
+			Some(public_key) => public_key.clone(),
+			None => {
+				let key = keystore.generate("")?;
+				let public_key = key.public();
+				info!("Generated a new keypair: {:?}", public_key);
+
+				public_key
+			}
+		};
 
 		let (client, on_demand) = Components::build_client(&config, executor)?;
 		let best_header = client.best_block_header()?;
@@ -218,6 +226,12 @@ impl<Components> Service<Components>
 		// Telemetry
 		let telemetry = match config.telemetry_url {
 			Some(url) => {
+				let mut pubkey = String::new();
+
+				for ch in public_key.as_slice() {
+					write!(pubkey, "{:02x}", ch).expect("Cannot fail on u8 slices; qed");
+				}
+
 				let name = config.name.clone();
 				let impl_name = config.impl_name.to_owned();
 				let version = version.clone();
@@ -231,6 +245,7 @@ impl<Components> Service<Components>
 							"version" => version.clone(),
 							"config" => "",
 							"chain" => chain_name.clone(),
+							"pubkey" => &pubkey,
 						);
 					}),
 				}))