multi: replace standalone gRPC web proxy with unified binary

Author: guggero

cmd/shushtar/main.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/jessevdk/go-flags"
+	"github.com/lightninglabs/shushtar"
+)
+
+// main starts the shushtar application.
+func main() {
+	err := shushtar.New().Run()
+	if e, ok := err.(*flags.Error); err != nil &&
+		(!ok || e.Type != flags.ErrHelp) {
+
+		_, _ = fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}

config.go

@@ -1,42 +1,181 @@
-package main
+package shushtar
 
 import (
+	"crypto/tls"
+	"fmt"
+	"net"
+	"os"
+	"path/filepath"
+	"strings"
+
 	"github.com/jessevdk/go-flags"
+	"github.com/lightninglabs/faraday"
+	"github.com/lightninglabs/loop/loopd"
+	"github.com/lightningnetwork/lnd"
+	"github.com/lightningnetwork/lnd/build"
+	"github.com/lightningnetwork/lnd/cert"
+	"github.com/lightningnetwork/lnd/lncfg"
+	"github.com/mwitkow/go-conntrack/connhelpers"
 )
 
-var (
-	defaultHTTPSListen = "localhost:8443"
-	defaultLndHost     = "localhost:10009"
-	defaultLoopHost    = "localhost:10010"
-	defaultTLSCertPath = "https.cert"
-	defaultTLSKeyPath  = "https.key"
-)
+// Config is the main configuration struct of shushtar. It contains all config
+// items of its enveloping subservers, each prefixed with their daemon's short
+// name.
+type Config struct {
+	HTTPSListen string          `long:"httpslisten" description:"host:port to listen for incoming HTTP/2 connections on"`
+	Lnd         *lnd.Config     `group:"lnd" namespace:"lnd"`
+	Faraday     *faraday.Config `group:"faraday" namespace:"faraday"`
+	Loop        *loopd.Config   `group:"loop" namespace:"loop"`
+}
+
+// loadLndConfig loads and sanitizes the lnd main configuration and hooks up all
+// loggers.
+func loadLndConfig(preCfg *Config) (*lnd.Config, error) {
+	// Show the version and exit if the version flag was specified.
+	appName := filepath.Base(os.Args[0])
+	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
+	usageMessage := fmt.Sprintf("Use %s -h to show usage", appName)
+	if preCfg.Lnd.ShowVersion {
+		fmt.Println(appName, "version", build.Version(),
+			"commit="+build.Commit)
+		os.Exit(0)
+	}
+
+	// If the config file path has not been modified by the user, then we'll
+	// use the default config file path. However, if the user has modified
+	// their lnddir, then we should assume they intend to use the config
+	// file within it.
+	configFileDir := lnd.CleanAndExpandPath(preCfg.Lnd.LndDir)
+	configFilePath := lnd.CleanAndExpandPath(preCfg.Lnd.ConfigFile)
+	if configFileDir != lnd.DefaultLndDir {
+		if configFilePath == lnd.DefaultConfigFile {
+			configFilePath = filepath.Join(
+				configFileDir, lncfg.DefaultConfigFilename,
+			)
+		}
+	}
+
+	// Next, load any additional configuration options from the file.
+	var configFileError error
+	cfg := preCfg
+	if err := flags.IniParse(configFilePath, cfg); err != nil {
+		// If it's a parsing related error, then we'll return
+		// immediately, otherwise we can proceed as possibly the config
+		// file doesn't exist which is OK.
+		if _, ok := err.(*flags.IniError); ok {
+			return nil, err
+		}
+
+		configFileError = err
+	}
 
-type config struct {
-	HTTPSListen string `long:"httpslisten" description:"host:port to listen for incoming HTTP/2 connections on"`
-	LNDHost     string `long:"lndhost" description:"host:port that LND listens for RPC connections on"`
-	LoopHost    string `long:"loophost" description:"host:port that Loop listens for RPC connections on"`
-	TLSCertPath string `long:"tlscertpath" description:"path to the TLS cert to use for HTTPS requests"`
-	TLSKeyPath  string `long:"tlskeypath" description:"path to the TLS key to use for HTTPS requests"`
-}
-
-// loadConfig starts with a skeleton default config, and reads in user provided
-// configuration from the command line. It does not provide a full set of
-// defaults or validate user input.
-func loadConfig() (*config, error) {
-	// Start with a default config.
-	config := &config{
-		HTTPSListen: defaultHTTPSListen,
-		LNDHost:     defaultLndHost,
-		LoopHost:    defaultLoopHost,
-		TLSCertPath: defaultTLSCertPath,
-		TLSKeyPath:  defaultTLSKeyPath,
-	}
-
-	// Parse command line options to obtain user specified values.
-	if _, err := flags.Parse(config); err != nil {
+	// Finally, parse the remaining command line options again to ensure
+	// they take precedence.
+	if _, err := flags.Parse(cfg); err != nil {
 		return nil, err
 	}
 
-	return config, nil
+	// Make sure everything we just loaded makes sense.
+	cleanCfg, err := lnd.ValidateConfig(*cfg.Lnd, usageMessage)
+	if err != nil {
+		return nil, err
+	}
+
+	// With the validated config obtained, we now know that the root logging
+	// system of lnd is initialized and we can hook up our own loggers now.
+	SetupLoggers(cleanCfg.LogWriter)
+
+	// Warn about missing config file only after all other configuration is
+	// done. This prevents the warning on help messages and invalid options.
+	// Note this should go directly before the return.
+	if configFileError != nil {
+		log.Warnf("%v", configFileError)
+	}
+
+	return cleanCfg, nil
+}
+
+func getNetwork(cfg *lncfg.Chain) (string, error) {
+	switch {
+	case cfg.MainNet:
+		return "mainnet", nil
+
+	case cfg.TestNet3:
+		return "testnet", nil
+
+	case cfg.RegTest:
+		return "regtest", nil
+
+	case cfg.SimNet:
+		return "simnet", nil
+
+	default:
+		return "", fmt.Errorf("no network selected")
+	}
+}
+
+func buildTLSConfigForHttp2(config *lnd.Config) (*tls.Config, error) {
+	tlsCert, _, err := cert.LoadCert(config.TLSCertPath, config.TLSKeyPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed reading TLS server keys: %v",
+			err)
+	}
+	tlsConfig := cert.TLSConfFromCert(tlsCert)
+	tlsConfig.CipherSuites = append(
+		tlsConfig.CipherSuites,
+		tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	)
+	tlsConfig, err = connhelpers.TlsConfigWithHttp2Enabled(tlsConfig)
+	if err != nil {
+		return nil, fmt.Errorf("can't configure h2 handling: %v", err)
+	}
+	return tlsConfig, nil
+}
+
+// onDemandListener is a net.Listener that only actually starts to listen on a
+// network port once the Accept method is called.
+type onDemandListener struct {
+	addr net.Addr
+	lis  net.Listener
+}
+
+// Accept waits for and returns the next connection to the listener.
+func (l *onDemandListener) Accept() (net.Conn, error) {
+	if l.lis == nil {
+		var err error
+		l.lis, err = net.Listen(parseNetwork(l.addr), l.addr.String())
+		if err != nil {
+			return nil, err
+		}
+	}
+	return l.lis.Accept()
+}
+
+// Close closes the listener.
+// Any blocked Accept operations will be unblocked and return errors.
+func (l *onDemandListener) Close() error {
+	return l.lis.Close()
+}
+
+// Addr returns the listener's network address.
+func (l *onDemandListener) Addr() net.Addr {
+	return l.addr
+}
+
+// parseNetwork parses the network type of the given address.
+func parseNetwork(addr net.Addr) string {
+	switch addr := addr.(type) {
+	// TCP addresses resolved through net.ResolveTCPAddr give a default
+	// network of "tcp", so we'll map back the correct network for the given
+	// address. This ensures that we can listen on the correct interface
+	// (IPv4 vs IPv6).
+	case *net.TCPAddr:
+		if addr.IP.To4() != nil {
+			return "tcp4"
+		}
+		return "tcp6"
+
+	default:
+		return addr.Network()
+	}
 }

go.mod

@@ -1,21 +1,35 @@
 module github.com/lightninglabs/shushtar
 
-go 1.14
-
 require (
+	github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f
 	github.com/desertbit/timer v0.0.0-20180107155436-c41aec40b27f // indirect
 	github.com/gorilla/websocket v1.4.2 // indirect
-	github.com/grpc-ecosystem/go-grpc-middleware v1.2.0
-	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0
+	github.com/grpc-ecosystem/grpc-gateway v1.12.2
 	github.com/improbable-eng/grpc-web v0.12.0
 	github.com/jessevdk/go-flags v1.4.0
-	github.com/jpillora/backoff v1.0.0 // indirect
+	github.com/lightninglabs/faraday v0.1.0-alpha.0.20200518080657-d3726a59507c
+	github.com/lightninglabs/loop v0.6.2-beta.0.20200528104150-c281cab8a036
+	github.com/lightningnetwork/lnd v0.10.1-beta.rc1
+	github.com/lightningnetwork/lnd/cert v1.0.2
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f
 	github.com/mwitkow/grpc-proxy v0.0.0-20181017164139-0f1106ef9c76
 	github.com/prometheus/client_golang v1.5.1 // indirect
+	github.com/rakyll/statik v0.1.7
 	github.com/rs/cors v1.7.0 // indirect
-	github.com/sirupsen/logrus v1.5.0
-	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e
+	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e // indirect
 	golang.org/x/sys v0.0.0-20200406155108-e3b113bbe6a4 // indirect
 	google.golang.org/grpc v1.28.0
+	gopkg.in/macaroon-bakery.v2 v2.1.0
+	gopkg.in/macaroon.v2 v2.1.0
 )
+
+// Manually solve the conflict between loop's lndclient version of lnd and what
+// we explicitly need for the unified binary to work.
+replace github.com/lightningnetwork/lnd => github.com/lightningnetwork/lnd v0.10.0-beta.rc6.0.20200528052558-24c865450a77
+
+// Needed because lnd now imports the etcd client which doesn't follow the go
+// mod guidelines. Unfortunately replace directives from dependency projects
+// aren't picked up so we need to specify this here and in lnd.
+replace github.com/coreos/go-systemd => github.com/coreos/go-systemd/v22 v22.0.0
+
+go 1.13