Add --chain=X argument, and use it to determine chain when DB is empty.

server/args.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/akamensky/argparse"
 	pb "github.com/lbryio/herald.go/protobuf/go"
+	"github.com/lbryio/lbcd/chaincfg"
 )
 
 const (
@@ -21,6 +22,7 @@ type Args struct {
 	Host                        string
 	Port                        string
 	DBPath                      string
+	Chain                       *string
 	EsHost                      string
 	EsPort                      string
 	PrometheusPort              string
@@ -112,6 +114,8 @@ func ParseArgs(searchRequest *pb.SearchRequest) *Args {
 	host := parser.String("", "rpchost", &argparse.Options{Required: false, Help: "RPC host", Default: DefaultHost})
 	port := parser.String("", "rpcport", &argparse.Options{Required: false, Help: "RPC port", Default: DefaultPort})
 	dbPath := parser.String("", "db-path", &argparse.Options{Required: false, Help: "RocksDB path", Default: DefaultDBPath})
+	chain := parser.Selector("", "chain", []string{chaincfg.MainNetParams.Name, chaincfg.TestNet3Params.Name, chaincfg.RegressionNetParams.Name, "testnet"},
+		&argparse.Options{Required: false, Help: "Which chain to use, default is 'mainnet'. Values 'regtest' and 'testnet' are for testing", Default: chaincfg.MainNetParams.Name})
 	esHost := parser.String("", "eshost", &argparse.Options{Required: false, Help: "elasticsearch host", Default: DefaultEsHost})
 	esPort := parser.String("", "esport", &argparse.Options{Required: false, Help: "elasticsearch port", Default: DefaultEsPort})
 	prometheusPort := parser.String("", "prometheus-port", &argparse.Options{Required: false, Help: "prometheus port", Default: DefaultPrometheusPort})
@@ -159,6 +163,7 @@ func ParseArgs(searchRequest *pb.SearchRequest) *Args {
 		Host:                        *host,
 		Port:                        *port,
 		DBPath:                      *dbPath,
+		Chain:                       chain,
 		EsHost:                      *esHost,
 		EsPort:                      *esPort,
 		PrometheusPort:              *prometheusPort,

server/server.go

@@ -274,18 +274,40 @@ func MakeHubServer(ctx context.Context, args *Args) *Server {
 		}
 	}
 
-	chain := chaincfg.MainNetParams
+	dbChain := (*chaincfg.Params)(nil)
 	if myDB != nil && myDB.LastState != nil && myDB.LastState.Genesis != nil {
 		// The chain params can be inferred from DBStateValue.
 		switch *myDB.LastState.Genesis {
 		case *chaincfg.MainNetParams.GenesisHash:
-			chain = chaincfg.MainNetParams
+			dbChain = &chaincfg.MainNetParams
 		case *chaincfg.TestNet3Params.GenesisHash:
-			chain = chaincfg.TestNet3Params
+			dbChain = &chaincfg.TestNet3Params
 		case *chaincfg.RegressionNetParams.GenesisHash:
-			chain = chaincfg.RegressionNetParams
+			dbChain = &chaincfg.RegressionNetParams
 		}
 	}
+	cliChain := (*chaincfg.Params)(nil)
+	if args.Chain != nil {
+		switch *args.Chain {
+		case chaincfg.MainNetParams.Name:
+			cliChain = &chaincfg.MainNetParams
+		case chaincfg.TestNet3Params.Name, "testnet":
+			cliChain = &chaincfg.TestNet3Params
+		case chaincfg.RegressionNetParams.Name:
+			cliChain = &chaincfg.RegressionNetParams
+		}
+	}
+	chain := chaincfg.MainNetParams
+	if dbChain != nil && cliChain != nil {
+		if dbChain != cliChain {
+			logrus.Warnf("network: %v (from db) conflicts with %v (from cli)", dbChain.Name, cliChain.Name)
+		}
+		chain = *dbChain
+	} else if dbChain != nil {
+		chain = *dbChain
+	} else if cliChain != nil {
+		chain = *cliChain
+	}
 	logrus.Infof("network: %v", chain.Name)
 
 	s := &Server{