Support config

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"encoding/json"
 	"log"
 	"math/rand"
 	"os"
@@ -13,18 +14,22 @@ import (
 	"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
 )
 
+var mainParams struct {
+	Config string `short:"f" long:"config" description:"config file path"`
+}
+
 var params struct {
-	Connect          string  `short:"c" long:"connect" description:"connect to lnd using host:port" default:"127.0.0.1:10009"`
-	TLSCert          string  `short:"t" long:"tlscert" description:"path to tls.cert to connect" required:"false"`
-	MacaroonDir      string  `long:"macaroon.dir" description:"path to the macaroon directory" required:"false"`
-	MacaroonFilename string  `long:"macaroon.filename" description:"macaroon filename" default:"admin.macaroon"`
-	Network          string  `short:"n" long:"network" description:"bitcoin network to use" default:"mainnet"`
-	FromPerc         int64   `long:"pfrom" description:"channels with less than this inbound liquidity percentage will be considered as source channels" default:"50"`
-	ToPerc           int64   `long:"pto" description:"channels with less than this outbound liquidity percentage will be considered as target channels" default:"50"`
-	Perc             int64   `short:"p" long:"perc" description:"use this value as both pfrom and pto from above" default:"0"`
-	Amount           int64   `short:"a" long:"amount" description:"amount to rebalance" default:"0"`
-	EconRatio        float64 `long:"econ-ratio" description:"economical ratio for fee limit calculation as a multiple of target channel fee (for example, 0.5 means you want to pay at max half the fee you might earn for routing out of the target channel)" default:"1"`
-	ProbeSteps       int     `short:"b" long:"probe" description:"if the payment fails at the last hop try to probe lower amount using binary search" default:"0"`
+	Connect          string  `short:"c" long:"connect" description:"connect to lnd using host:port" json:"connect"`
+	TLSCert          string  `short:"t" long:"tlscert" description:"path to tls.cert to connect" required:"false" json:"tlscert"`
+	MacaroonDir      string  `long:"macaroon.dir" description:"path to the macaroon directory" required:"false" json:"macaroon.dir"`
+	MacaroonFilename string  `long:"macaroon.filename" description:"macaroon filename" json:"macaroon.filename"`
+	Network          string  `short:"n" long:"network" description:"bitcoin network to use" json:"network"`
+	FromPerc         int64   `long:"pfrom" description:"channels with less than this inbound liquidity percentage will be considered as source channels" json:"pfrom"`
+	ToPerc           int64   `long:"pto" description:"channels with less than this outbound liquidity percentage will be considered as target channels" json:"pto"`
+	Perc             int64   `short:"p" long:"perc" description:"use this value as both pfrom and pto from above" json:"perc"`
+	Amount           int64   `short:"a" long:"amount" description:"amount to rebalance" json:"amount"`
+	EconRatio        float64 `long:"econ-ratio" description:"economical ratio for fee limit calculation as a multiple of target channel fee (for example, 0.5 means you want to pay at max half the fee you might earn for routing out of the target channel)" json:"econ_ratio"`
+	ProbeSteps       int     `short:"b" long:"probe" description:"if the payment fails at the last hop try to probe lower amount using binary search" json:"probe_steps"`
 }
 
 type regolancer struct {
@@ -38,12 +43,45 @@ type regolancer struct {
 	chanCache    map[uint64]*lnrpc.ChannelEdge
 }
 
+func loadConfig() {
+	flags.Parse(&mainParams)
+	if mainParams.Config == "" {
+		return
+	}
+	f, err := os.Open(mainParams.Config)
+	if err != nil {
+		log.Fatalf("Error opening config file %s: %s", mainParams.Config, err)
+	} else {
+		defer f.Close()
+		err = json.NewDecoder(f).Decode(&params)
+		if err != nil {
+			log.Fatalf("Error reading config file %s: %s", mainParams.Config, err)
+		}
+	}
+}
+
 func main() {
-	_, err := flags.Parse(&params)
+	rand.Seed(time.Now().UnixNano())
+	loadConfig()
+	_, err := flags.NewParser(&params, flags.Default|flags.IgnoreUnknown).Parse()
 	if err != nil {
 		os.Exit(1)
 	}
-	rand.Seed(time.Now().UnixNano())
+	if params.Connect == "" {
+		params.Connect = "127.0.0.1:10009"
+	}
+	if params.MacaroonFilename == "" {
+		params.MacaroonFilename = "admin.macaroon"
+	}
+	if params.FromPerc == 0 {
+		params.FromPerc = 50
+	}
+	if params.ToPerc == 0 {
+		params.ToPerc = 50
+	}
+	if params.EconRatio == 0 {
+		params.EconRatio = 1
+	}
 	if params.Perc > 0 {
 		params.FromPerc = params.Perc
 		params.ToPerc = params.Perc