Merge pull request #284 from zcash/zcash-rpc-from-flags

Added option to provide Zcashd RPC parameters from flags

Author: benzcash

cmd/root.go

@@ -11,6 +11,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/btcsuite/btcd/rpcclient"
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	grpc_prometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
@@ -45,6 +46,10 @@ var rootCmd = &cobra.Command{
 			LogLevel:            viper.GetUint64("log-level"),
 			LogFile:             viper.GetString("log-file"),
 			ZcashConfPath:       viper.GetString("zcash-conf-path"),
+			RPCUser:             viper.GetString("rpcuser"),
+			RPCPassword:         viper.GetString("rpcpassword"),
+			RPCHost:             viper.GetString("rpchost"),
+			RPCPort:             viper.GetString("rpcport"),
 			NoTLSVeryInsecure:   viper.GetBool("no-tls-very-insecure"),
 			GenCertVeryInsecure: viper.GetBool("gen-cert-very-insecure"),
 			DataDir:             viper.GetString("data-dir"),
@@ -61,7 +66,7 @@ var rootCmd = &cobra.Command{
 		if !fileExists(opts.LogFile) {
 			os.OpenFile(opts.LogFile, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0666)
 		}
-		if !opts.Darkside {
+		if !opts.Darkside && (opts.RPCUser == "" || opts.RPCPassword == "" || opts.RPCHost == "" || opts.RPCPort == "") {
 			filesThatShouldExist = append(filesThatShouldExist, opts.ZcashConfPath)
 		}
 		if !opts.NoTLSVeryInsecure && !opts.GenCertVeryInsecure {
@@ -176,10 +181,16 @@ func startServer(opts *common.Options) error {
 	var blockHeight int
 	var chainName string
 	var branchID string
+	var rpcClient *rpcclient.Client
+	var err error
 	if opts.Darkside {
 		chainName = "darkside"
 	} else {
-		rpcClient, err := frontend.NewZRPCFromConf(opts.ZcashConfPath)
+		if opts.RPCUser != "" && opts.RPCPassword != "" && opts.RPCHost != "" && opts.RPCPort != "" {
+			rpcClient, err = frontend.NewZRPCFromFlags(opts)
+		} else {
+			rpcClient, err = frontend.NewZRPCFromConf(opts.ZcashConfPath)
+		}
 		if err != nil {
 			common.Log.WithFields(logrus.Fields{
 				"error": err,
@@ -287,6 +298,10 @@ func init() {
 	rootCmd.Flags().Int("log-level", int(logrus.InfoLevel), "log level (logrus 1-7)")
 	rootCmd.Flags().String("log-file", "./server.log", "log file to write to")
 	rootCmd.Flags().String("zcash-conf-path", "./zcash.conf", "conf file to pull RPC creds from")
+	rootCmd.Flags().String("rpcuser", "", "RPC user name")
+	rootCmd.Flags().String("rpcpassword", "", "RPC password")
+	rootCmd.Flags().String("rpchost", "", "RPC host")
+	rootCmd.Flags().String("rpcport", "", "RPC host port")
 	rootCmd.Flags().Bool("no-tls-very-insecure", false, "run without the required TLS certificate, only for debugging, DO NOT use in production")
 	rootCmd.Flags().Bool("gen-cert-very-insecure", false, "run with self-signed TLS certificate, only for debugging, DO NOT use in production")
 	rootCmd.Flags().Bool("redownload", false, "re-fetch all blocks from zcashd; reinitialize local cache files")
@@ -308,6 +323,10 @@ func init() {
 	viper.SetDefault("log-file", "./server.log")
 	viper.BindPFlag("zcash-conf-path", rootCmd.Flags().Lookup("zcash-conf-path"))
 	viper.SetDefault("zcash-conf-path", "./zcash.conf")
+	viper.BindPFlag("rpcuser", rootCmd.Flags().Lookup("rpcuser"))
+	viper.BindPFlag("rpcpassword", rootCmd.Flags().Lookup("rpcpassword"))
+	viper.BindPFlag("rpchost", rootCmd.Flags().Lookup("rpchost"))
+	viper.BindPFlag("rpcport", rootCmd.Flags().Lookup("rpcport"))
 	viper.BindPFlag("no-tls-very-insecure", rootCmd.Flags().Lookup("no-tls-very-insecure"))
 	viper.SetDefault("no-tls-very-insecure", false)
 	viper.BindPFlag("gen-cert-very-insecure", rootCmd.Flags().Lookup("gen-cert-very-insecure"))

common/common.go

@@ -33,6 +33,10 @@ type Options struct {
 	LogLevel            uint64 `json:"log_level,omitempty"`
 	LogFile             string `json:"log_file,omitempty"`
 	ZcashConfPath       string `json:"zcash_conf,omitempty"`
+	RPCUser             string `json:"rpcuser"`
+	RPCPassword         string `json:"rpcpassword"`
+	RPCHost             string `json:"rpchost"`
+	RPCPort             string `json:"rpcport"`
 	NoTLSVeryInsecure   bool   `json:"no_tls_very_insecure,omitempty"`
 	GenCertVeryInsecure bool   `json:"gen_cert_very_insecure,omitempty"`
 	Redownload          bool   `json:"redownload"`

frontend/rpc_client.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/btcsuite/btcd/rpcclient"
 	"github.com/pkg/errors"
+	"github.com/zcash/lightwalletd/common"
 	ini "gopkg.in/ini.v1"
 )
 
@@ -21,6 +22,19 @@ func NewZRPCFromConf(confPath interface{}) (*rpcclient.Client, error) {
 	return rpcclient.New(connCfg, nil)
 }
 
+// NewZRPCFromFlags gets zcashd rpc connection information from provided flags.
+func NewZRPCFromFlags(opts *common.Options) (*rpcclient.Client, error) {
+	// Connect to local Zcash RPC server using HTTP POST mode.
+	connCfg := &rpcclient.ConnConfig{
+		Host:         net.JoinHostPort(opts.RPCHost, opts.RPCPort),
+		User:         opts.RPCUser,
+		Pass:         opts.RPCPassword,
+		HTTPPostMode: true, // Zcash only supports HTTP POST mode
+		DisableTLS:   true, // Zcash does not provide TLS by default
+	}
+	return rpcclient.New(connCfg, nil)
+}
+
 // If passed a string, interpret as a path, open and read; if passed
 // a byte slice, interpret as the config file content (used in testing).
 func connFromConf(confPath interface{}) (*rpcclient.ConnConfig, error) {