loopd: Consider network when making LND paths

In this commit we consider the passed network options when assuming the
LND macaroon path if not passed by user

loopd/config.go

@@ -51,6 +51,14 @@ var (
 	// deprecated --lnd.macaroondir config option is used.
 	defaultLndMacaroon = "admin.macaroon"
 
+	// DefaultLndMacaroonPath is the default mainnet admin macaroon path of
+	// LND.
+	DefaultLndMacaroonPath = filepath.Join(
+		btcutil.AppDataDir("lnd", false),
+		"data", "chain", "bitcoin", DefaultNetwork,
+		defaultLndMacaroon,
+	)
+
 	// DefaultTLSCertPath is the default full path of the autogenerated TLS
 	// certificate.
 	DefaultTLSCertPath = filepath.Join(
@@ -171,12 +179,8 @@ func DefaultConfig() Config {
 		MaxLSATFee:      lsat.DefaultMaxRoutingFeeSats,
 		LoopOutMaxParts: defaultLoopOutMaxParts,
 		Lnd: &lndConfig{
-			Host: "localhost:10009",
-			MacaroonPath: filepath.Join(
-				btcutil.AppDataDir("lnd", false),
-				"data", "chain", "bitcoin", DefaultNetwork,
-				"admin.macaroon",
-			),
+			Host:         "localhost:10009",
+			MacaroonPath: DefaultLndMacaroonPath,
 		},
 	}
 }
@@ -252,6 +256,16 @@ func Validate(cfg *Config) error {
 		)
 	}
 
+	// If the user doesn't specify Lnd.MacaroonPath, we'll reassemble it
+	// with the passed Network options.
+	if cfg.Lnd.MacaroonPath == DefaultLndMacaroonPath {
+		cfg.Lnd.MacaroonPath = filepath.Join(
+			btcutil.AppDataDir("lnd", false),
+			"data", "chain", "bitcoin", cfg.Network,
+			defaultLndMacaroon,
+		)
+	}
+
 	// If either of these directories do not exist, create them.
 	if err := os.MkdirAll(cfg.DataDir, os.ModePerm); err != nil {
 		return err