fix(lnd): don't default lnd clients as disabled

This fixes a bug introduced in #672 whereby the lnd clients are not
properly initializing. That PR removed synchronous calls to methods that
had asynchronous alternatives, which necessitated moving code from the
synchronous `LndClient` constructor to an asynchronous init method.

Included in the code that was moved was logic to determine whether to
change the client's status from the default value of `Disabled`. This
impacted the xud initialization procedure which would only attempt
to initialize (or previously verify a connection for) an lnd client that
was not disabled.

This PR creates a new `NotInitialized` status as the default to reflect
the status of a newly created client. It gets changed when the `init`
method is called.

lib/BaseClient.ts

@@ -2,6 +2,7 @@ import Logger from './Logger';
 import { EventEmitter } from 'events';
 
 enum ClientStatus {
+  NotInitialized,
   Disabled,
   Disconnected,
   ConnectionVerified,
@@ -12,7 +13,7 @@ enum ClientStatus {
  * A base class to represent a client for an external service such as LND or Raiden.
  */
 abstract class BaseClient extends EventEmitter {
-  protected status: ClientStatus = ClientStatus.Disabled;
+  protected status: ClientStatus = ClientStatus.NotInitialized;
 
   constructor(protected logger: Logger) {
     super();

lib/Xud.ts

@@ -70,15 +70,11 @@ class Xud extends EventEmitter {
       this.db = new DB(loggers.db, this.config.dbpath);
       await this.db.init(this.config.initdb);
 
-      // setup LND clients and connect if configured
+      // setup LND clients and initialize
       this.lndbtcClient = new LndClient(this.config.lndbtc, loggers.lnd);
-      if (!this.lndbtcClient.isDisabled()) {
-        initPromises.push(this.lndbtcClient.init());
-      }
+      initPromises.push(this.lndbtcClient.init());
       this.lndltcClient = new LndClient(this.config.lndltc, loggers.lnd);
-      if (!this.lndltcClient.isDisabled()) {
-        initPromises.push(this.lndltcClient.init());
-      }
+      initPromises.push(this.lndltcClient.init());
 
       // setup raiden client and connect if configured
       this.raidenClient = new RaidenClient(this.config.raiden, loggers.raiden);

lib/lndclient/LndClient.ts

@@ -72,37 +72,36 @@ class LndClient extends BaseClient {
 
   /** Initializes the client for calls to lnd and verifies that we can connect to it.  */
   public init = async () => {
-    let shouldEnable = true;
     const { disable, certpath, macaroonpath, nomacaroons, host, port } = this.config;
+    let shouldDisable = disable;
 
-    if (disable) {
-      shouldEnable = false;
-    }
     if (!(await exists(certpath))) {
       this.logger.error('could not find lnd certificate, is lnd installed?');
-      shouldEnable = false;
+      shouldDisable = true;
     }
     if (!nomacaroons && !(await exists(macaroonpath))) {
       this.logger.error('could not find lnd macaroon, is lnd installed?');
-      shouldEnable = false;
+      shouldDisable = true;
     }
-    if (shouldEnable) {
-      assert(this.cltvDelta > 0, 'cltvdelta must be a positive number');
-      this.uri = `${host}:${port}`;
-      const lndCert = await readFile(certpath);
-      this.credentials = grpc.credentials.createSsl(lndCert);
-
-      this.meta = new grpc.Metadata();
-      if (!nomacaroons) {
-        const adminMacaroon = await readFile(macaroonpath);
-        this.meta.add('macaroon', adminMacaroon.toString('hex'));
-      } else {
-        this.logger.info(`macaroons are disabled for lnd at ${this.uri}`);
-      }
-      // set status as disconnected until we can verify the connection
-      this.setStatus(ClientStatus.Disconnected);
-      await this.verifyConnection();
+    if (shouldDisable) {
+      return;
+    }
+
+    assert(this.cltvDelta > 0, 'cltvdelta must be a positive number');
+    this.uri = `${host}:${port}`;
+    const lndCert = await readFile(certpath);
+    this.credentials = grpc.credentials.createSsl(lndCert);
+
+    this.meta = new grpc.Metadata();
+    if (!nomacaroons) {
+      const adminMacaroon = await readFile(macaroonpath);
+      this.meta.add('macaroon', adminMacaroon.toString('hex'));
+    } else {
+      this.logger.info(`macaroons are disabled for lnd at ${this.uri}`);
     }
+    // set status as disconnected until we can verify the connection
+    this.setStatus(ClientStatus.Disconnected);
+    return this.verifyConnection();
   }
 
   public get pubKey() {

lib/raidenclient/RaidenClient.ts

@@ -112,8 +112,8 @@ class RaidenClient extends BaseClient {
     this.port = port;
     this.host = host;
 
-    if (!disable) {
-      this.setStatus(ClientStatus.Disconnected);
+    if (disable) {
+      this.setStatus(ClientStatus.Disabled);
     }
   }