fix(lnd): waitForReady infinite deadline (#1152)

This fixes a bug where the first attempt to verify a connection to
lnd would fail on the first attempt due to the `deadline` of 0 for the
`waitForReady` being exceeded immediately with the latest version of
lnd. Subsequent attempts would not exceed the deadline.

Instead, this always uses a deadline of infinity meaning xud will
always wait for lnd to be online before it attempts a `GetInfo` call
to verify the connection. This leverages the recently added
`verifyConnectionWithTimeout` logic to timeout the initial connection
verification if lnd remains offline so that it doesn't hold up the
xud initialization procedure.

Author: sangaman

lib/lndclient/LndClient.ts

@@ -237,12 +237,10 @@ class LndClient extends SwapClient {
     }
 
     if (!this.isConnected()) {
-      this.logger.debug(`trying to verify connection to lnd at ${this.uri}`);
+      this.logger.info(`trying to verify connection to lnd at ${this.uri}`);
       const lightningClient = new LightningClient(this.uri, this.credentials);
       const clientReadyPromise = new Promise((resolve, reject) => {
-        // if we're not initialized, don't wait for lnd to come online and mark client as disconnected immediately
-        const deadline = this.isNotInitialized() ? 0 : Number.POSITIVE_INFINITY;
-        lightningClient.waitForReady(deadline, (err) => {
+        lightningClient.waitForReady(Number.POSITIVE_INFINITY, (err) => {
           if (err) {
             reject(err);
           } else {
@@ -310,8 +308,8 @@ class LndClient extends SwapClient {
           this.lightning = undefined;
           await this.setStatus(ClientStatus.WaitingUnlock);
         } else {
-          this.logger.error(`could not verify connection to lnd at ${this.uri}, error: ${JSON.stringify(err)},
-            retrying in ${LndClient.RECONNECT_TIMER} ms`);
+          const errStr = typeof(err) === 'string' ? err : JSON.stringify(err);
+          this.logger.error(`could not verify connection at ${this.uri}, error: ${errStr}, retrying in ${LndClient.RECONNECT_TIMER} ms`);
           await this.disconnect();
         }
       }

lib/swaps/SwapClient.ts

@@ -78,6 +78,7 @@ abstract class SwapClient extends EventEmitter {
     return new Promise<void>((resolve, reject) => {
       const verifyTimeout = setTimeout(() => {
         // we could not verify the connection within the allotted time
+        this.logger.info(`could not verify connection within initialization time limit of ${SwapClient.INITIALIZATION_TIME_LIMIT}`);
         resolve();
       }, SwapClient.INITIALIZATION_TIME_LIMIT);
       this.verifyConnection().then(() => {