lnd: log error if any throughout initialization

In this commit, we establish a new pattern to always log errors before
returning them to the higher level caller, which then prints the error
to stdout/stderr. Errors returned are usually lowercase, but we decide
not to apply this rule here as these errors should not be chained
forward.

lnd.go

@@ -150,7 +150,9 @@ func Main() error {
 	if cfg.CPUProfile != "" {
 		f, err := os.Create(cfg.CPUProfile)
 		if err != nil {
-			ltndLog.Errorf("Unable to create cpu profile: %v", err)
+			err := fmt.Errorf("Unable to create CPU profile: %v",
+				err)
+			ltndLog.Error(err)
 			return err
 		}
 		pprof.StartCPUProfile(f)
@@ -171,7 +173,8 @@ func Main() error {
 		channeldb.OptionSetChannelCacheSize(cfg.Caches.ChannelCacheSize),
 	)
 	if err != nil {
-		ltndLog.Errorf("unable to open channeldb: %v", err)
+		err := fmt.Errorf("Unable to open channeldb: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	defer chanDB.Close()
@@ -183,6 +186,8 @@ func Main() error {
 
 	tlsCfg, restCreds, restProxyDest, err := getTLSConfig(cfg)
 	if err != nil {
+		err := fmt.Errorf("Unable to load TLS credentials: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 
@@ -204,6 +209,9 @@ func Main() error {
 			mainChain.ChainDir,
 		)
 		if err != nil {
+			err := fmt.Errorf("Unable to initialize neutrino "+
+				"backend: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 		defer neutrinoCleanUp()
@@ -230,6 +238,9 @@ func Main() error {
 			restDialOpts, restProxyDest, tlsCfg,
 		)
 		if err != nil {
+			err := fmt.Errorf("Unable to set up wallet password "+
+				"listeners: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 
@@ -251,7 +262,9 @@ func Main() error {
 			networkDir, macaroons.IPLockChecker,
 		)
 		if err != nil {
-			srvrLog.Errorf("unable to create macaroon service: %v", err)
+			err := fmt.Errorf("Unable to set up macaroon "+
+				"authentication: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 		defer macaroonService.Close()
@@ -259,7 +272,8 @@ func Main() error {
 		// Try to unlock the macaroon store with the private password.
 		err = macaroonService.CreateUnlock(&privateWalletPw)
 		if err != nil {
-			srvrLog.Errorf("unable to unlock macaroons: %v", err)
+			err := fmt.Errorf("Unable to unlock macaroons: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 
@@ -272,8 +286,9 @@ func Main() error {
 				cfg.ReadMacPath, cfg.InvoiceMacPath,
 			)
 			if err != nil {
-				ltndLog.Errorf("unable to create macaroon "+
+				err := fmt.Errorf("Unable to create macaroons "+
-					"files: %v", err)
+					"%v", err)
+				ltndLog.Error(err)
 				return err
 			}
 		}
@@ -288,7 +303,8 @@ func Main() error {
 		walletInitParams.Wallet, neutrinoCS,
 	)
 	if err != nil {
-		fmt.Printf("unable to create chain control: %v\n", err)
+		err := fmt.Errorf("Unable to create chain control: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 
@@ -306,6 +322,8 @@ func Main() error {
 		},
 	})
 	if err != nil {
+		err := fmt.Errorf("Unable to derive node private key: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	idPrivKey.Curve = btcec.S256()
@@ -323,7 +341,10 @@ func Main() error {
 		var err error
 		towerClientDB, err = wtdb.OpenClientDB(graphDir)
 		if err != nil {
-			ltndLog.Errorf("Unable to open watchtower client db: %v", err)
+			err := fmt.Errorf("Unable to open watchtower client "+
+				"database: %v", err)
+			ltndLog.Error(err)
+			return err
 		}
 		defer towerClientDB.Close()
 	}
@@ -339,7 +360,9 @@ func Main() error {
 
 		towerDB, err := wtdb.OpenTowerDB(towerDBDir)
 		if err != nil {
-			ltndLog.Errorf("Unable to open watchtower db: %v", err)
+			err := fmt.Errorf("Unable to open watchtower "+
+				"database: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 		defer towerDB.Close()
@@ -353,6 +376,9 @@ func Main() error {
 			},
 		)
 		if err != nil {
+			err := fmt.Errorf("Unable to derive watchtower "+
+				"private key: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 
@@ -371,13 +397,16 @@ func Main() error {
 			ChainHash:   *activeNetParams.GenesisHash,
 		}, lncfg.NormalizeAddresses)
 		if err != nil {
-			ltndLog.Errorf("Unable to configure watchtower: %v", err)
+			err := fmt.Errorf("Unable to configure watchtower: %v",
+				err)
+			ltndLog.Error(err)
 			return err
 		}
 
 		tower, err = watchtower.New(wtConfig)
 		if err != nil {
-			ltndLog.Errorf("Unable to create watchtower: %v", err)
+			err := fmt.Errorf("Unable to create watchtower: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 	}
@@ -389,7 +418,8 @@ func Main() error {
 		idPrivKey, walletInitParams.ChansToRestore,
 	)
 	if err != nil {
-		srvrLog.Errorf("unable to create server: %v\n", err)
+		err := fmt.Errorf("Unable to create server: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 
@@ -398,17 +428,20 @@ func Main() error {
 	// it at will.
 	atplCfg, err := initAutoPilot(server, cfg.Autopilot)
 	if err != nil {
-		ltndLog.Errorf("unable to init autopilot: %v", err)
+		err := fmt.Errorf("Unable to initialize autopilot: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 
 	atplManager, err := autopilot.NewManager(atplCfg)
 	if err != nil {
-		ltndLog.Errorf("unable to create autopilot manager: %v", err)
+		err := fmt.Errorf("Unable to create autopilot manager: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	if err := atplManager.Start(); err != nil {
-		ltndLog.Errorf("unable to start autopilot manager: %v", err)
+		err := fmt.Errorf("Unable to start autopilot manager: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	defer atplManager.Stop()
@@ -421,10 +454,13 @@ func Main() error {
 		tower, tlsCfg,
 	)
 	if err != nil {
-		srvrLog.Errorf("unable to start RPC server: %v", err)
+		err := fmt.Errorf("Unable to create RPC server: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	if err := rpcServer.Start(); err != nil {
+		err := fmt.Errorf("Unable to start RPC server: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	defer rpcServer.Stop()
@@ -436,6 +472,9 @@ func Main() error {
 	if !(cfg.Bitcoin.SimNet || cfg.Litecoin.SimNet) {
 		_, bestHeight, err := activeChainControl.chainIO.GetBestBlock()
 		if err != nil {
+			err := fmt.Errorf("Unable to determine chain tip: %v",
+				err)
+			ltndLog.Error(err)
 			return err
 		}
 
@@ -449,6 +488,9 @@ func Main() error {
 
 			synced, _, err := activeChainControl.wallet.IsSynced()
 			if err != nil {
+				err := fmt.Errorf("Unable to determine if "+
+					"wallet is synced: %v", err)
+				ltndLog.Error(err)
 				return err
 			}
 
@@ -461,6 +503,9 @@ func Main() error {
 
 		_, bestHeight, err = activeChainControl.chainIO.GetBestBlock()
 		if err != nil {
+			err := fmt.Errorf("Unable to determine chain tip: %v",
+				err)
+			ltndLog.Error(err)
 			return err
 		}
 
@@ -471,7 +516,8 @@ func Main() error {
 	// With all the relevant chains initialized, we can finally start the
 	// server itself.
 	if err := server.Start(); err != nil {
-		srvrLog.Errorf("unable to start server: %v\n", err)
+		err := fmt.Errorf("Unable to start server: %v", err)
+		ltndLog.Error(err)
 		return err
 	}
 	defer server.Stop()
@@ -481,15 +527,17 @@ func Main() error {
 	// stopped together with the autopilot service.
 	if cfg.Autopilot.Active {
 		if err := atplManager.StartAgent(); err != nil {
-			ltndLog.Errorf("unable to start autopilot agent: %v",
+			err := fmt.Errorf("Unable to start autopilot agent: %v",
 				err)
+			ltndLog.Error(err)
 			return err
 		}
 	}
 
 	if cfg.Watchtower.Active {
 		if err := tower.Start(); err != nil {
-			ltndLog.Errorf("Unable to start watchtower: %v", err)
+			err := fmt.Errorf("Unable to start watchtower: %v", err)
+			ltndLog.Error(err)
 			return err
 		}
 		defer tower.Stop()