cmd/loopd: show version on start up, add new --version flag

cmd/loopd/config.go

@@ -9,11 +9,12 @@ type lndConfig struct {
 type viewParameters struct{}
 
 type config struct {
-	Insecure   bool   `long:"insecure" description:"disable tls"`
-	Network    string `long:"network" description:"network to run on" choice:"regtest" choice:"testnet" choice:"mainnet" choice:"simnet"`
-	SwapServer string `long:"swapserver" description:"swap server address host:port"`
-	RPCListen  string `long:"rpclisten" description:"Address to listen on for gRPC clients"`
-	RESTListen string `long:"restlisten" description:"Address to listen on for REST clients"`
+	ShowVersion bool   `short:"V" long:"version" description:"Display version information and exit"`
+	Insecure    bool   `long:"insecure" description:"disable tls"`
+	Network     string `long:"network" description:"network to run on" choice:"regtest" choice:"testnet" choice:"mainnet" choice:"simnet"`
+	SwapServer  string `long:"swapserver" description:"swap server address host:port"`
+	RPCListen   string `long:"rpclisten" description:"Address to listen on for gRPC clients"`
+	RESTListen  string `long:"restlisten" description:"Address to listen on for REST clients"`
 
 	Lnd *lndConfig `group:"lnd" namespace:"lnd"`
 

cmd/loopd/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 
 	flags "github.com/jessevdk/go-flags"
@@ -72,6 +73,17 @@ func start() error {
 		return err
 	}
 
+	// Show the version and exit if the version flag was specified.
+	appName := filepath.Base(os.Args[0])
+	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
+	if config.ShowVersion {
+		fmt.Println(appName, "version", loop.Version())
+		os.Exit(0)
+	}
+
+	// Print the version before executing either primary directive.
+	logger.Infof("Version: %v", loop.Version())
+
 	// Execute command.
 	if parser.Active == nil {
 		return daemon(&config)