Update networking code to libp2p 0.14 (#4383)

* Entirely update substrate-telemetry to futures 0.3

* Add a Closed error

* Update to libp2p 0.14

* More work

* More work

* More work

* More work

* Fix warnings

* Remove unwrap()

* Work on tests fixing

* Fix network tests

* Fix external network tests

* Update libp2p and restore Yamux in discovery test

* Ignore DNS if initializatio nfails

* Restore variables ordering

* Forgot browser-utils

* Fix downfall after merge

* Fix tests

substrate/client/telemetry/src/lib.rs

@@ -60,11 +60,12 @@
 
 use futures::{prelude::*, channel::mpsc};
 use libp2p::{Multiaddr, wasm_ext};
-use log::warn;
+use log::{error, warn};
 use parking_lot::Mutex;
 use serde::{Serialize, Deserialize};
 use std::{pin::Pin, sync::Arc, task::{Context, Poll}, time::{Duration, Instant}};
 
+pub use libp2p::wasm_ext::ExtTransport;
 pub use slog_scope::with_logger;
 pub use slog;
 
@@ -129,8 +130,8 @@ pub struct Telemetry {
 /// where we extract the telemetry registration so that it continues running during the shutdown
 /// process.
 struct TelemetryInner {
-	/// Worker for the telemetry.
-	worker: worker::TelemetryWorker,
+	/// Worker for the telemetry. `None` if it failed to initialize.
+	worker: Option<worker::TelemetryWorker>,
 	/// Receives log entries for them to be dispatched to the worker.
 	receiver: mpsc::Receiver<async_record::AsyncRecord>,
 }
@@ -162,9 +163,17 @@ pub fn init_telemetry(config: TelemetryConfig) -> Telemetry {
 		slog_scope::set_global_logger(root)
 	};
 
+	let worker = match worker::TelemetryWorker::new(endpoints, config.wasm_external_transport) {
+		Ok(w) => Some(w),
+		Err(err) => {
+			error!(target: "telemetry", "Failed to initialize telemetry worker: {:?}", err);
+			None
+		}
+	};
+
 	Telemetry {
 		inner: Arc::new(Mutex::new(TelemetryInner {
-			worker: worker::TelemetryWorker::new(endpoints, config.wasm_external_transport),
+			worker,
 			receiver,
 		})),
 		_guard: Arc::new(guard),
@@ -209,15 +218,19 @@ impl Stream for Telemetry {
 		// The polling pattern is: poll the worker so that it processes its queue, then add one
 		// message from the receiver (if possible), then poll the worker again, and so on.
 		loop {
-			while let Poll::Ready(event) = inner.worker.poll(cx) {
-				// Right now we only have one possible event. This line is here in order to not
-				// forget to handle any possible new event type.
-				let worker::TelemetryWorkerEvent::Connected = event;
-				has_connected = true;
+			if let Some(worker) = inner.worker.as_mut() {
+				while let Poll::Ready(event) = worker.poll(cx) {
+					// Right now we only have one possible event. This line is here in order to not
+					// forget to handle any possible new event type.
+					let worker::TelemetryWorkerEvent::Connected = event;
+					has_connected = true;
+				}
 			}
 
 			if let Poll::Ready(Some(log_entry)) = Stream::poll_next(Pin::new(&mut inner.receiver), cx) {
-				log_entry.as_record_values(|rec, val| { let _ = inner.worker.log(rec, val); });
+				if let Some(worker) = inner.worker.as_mut() {
+					log_entry.as_record_values(|rec, val| { let _ = worker.log(rec, val); });
+				}
 			} else {
 				break;
 			}