[WIP] Split broker into components

Exploring #26092

broker/broker.go

@@ -7,22 +7,19 @@ package main
 
 import (
 	"container/heap"
-	"crypto/tls"
 	"flag"
 	"io"
 	"log"
-	"net/http"
+	"net"
+	"net/rpc"
 	"os"
 	"os/signal"
-	"strings"
 	"sync"
 	"syscall"
 	"time"
 
 	"git.torproject.org/pluggable-transports/snowflake.git/common/safelog"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
-	"golang.org/x/crypto/acme/autocert"
+	// "github.com/prometheus/client_golang/prometheus"
 )
 
 type BrokerContext struct {
@@ -105,7 +102,7 @@ func (ctx *BrokerContext) Broker() {
 					} else {
 						heap.Remove(ctx.restrictedSnowflakes, snowflake.index)
 					}
-					ctx.metrics.promMetrics.AvailableProxies.With(prometheus.Labels{"nat": request.natType, "type": request.proxyType}).Dec()
+					// ctx.metrics.promMetrics.AvailableProxies.With(prometheus.Labels{"nat": request.natType, "type": request.proxyType}).Dec()
 					delete(ctx.idToSnowflake, snowflake.id)
 					close(request.offerChannel)
 				}
@@ -131,7 +128,7 @@ func (ctx *BrokerContext) AddSnowflake(id string, proxyType string, natType stri
 	} else {
 		heap.Push(ctx.restrictedSnowflakes, snowflake)
 	}
-	ctx.metrics.promMetrics.AvailableProxies.With(prometheus.Labels{"nat": natType, "type": proxyType}).Inc()
+	// ctx.metrics.promMetrics.AvailableProxies.With(prometheus.Labels{"nat": natType, "type": proxyType}).Inc()
 	ctx.snowflakeLock.Unlock()
 	ctx.idToSnowflake[id] = snowflake
 	return snowflake
@@ -144,34 +141,29 @@ type ClientOffer struct {
 }
 
 func main() {
-	var acmeEmail string
-	var acmeHostnamesCommas string
-	var acmeCertCacheDir string
-	var addr string
 	var geoipDatabase string
 	var geoip6Database string
-	var disableTLS bool
-	var certFilename, keyFilename string
 	var disableGeoip bool
+
 	var metricsFilename string
 	var unsafeLogging bool
 
-	flag.StringVar(&acmeEmail, "acme-email", "", "optional contact email for Let's Encrypt notifications")
-	flag.StringVar(&acmeHostnamesCommas, "acme-hostnames", "", "comma-separated hostnames for TLS certificate")
-	flag.StringVar(&certFilename, "cert", "", "TLS certificate file")
-	flag.StringVar(&keyFilename, "key", "", "TLS private key file")
-	flag.StringVar(&acmeCertCacheDir, "acme-cert-cache", "acme-cert-cache", "directory in which certificates should be cached")
-	flag.StringVar(&addr, "addr", ":443", "address to listen on")
+	var socket string
+
 	flag.StringVar(&geoipDatabase, "geoipdb", "/usr/share/tor/geoip", "path to correctly formatted geoip database mapping IPv4 address ranges to country codes")
 	flag.StringVar(&geoip6Database, "geoip6db", "/usr/share/tor/geoip6", "path to correctly formatted geoip database mapping IPv6 address ranges to country codes")
-	flag.BoolVar(&disableTLS, "disable-tls", false, "don't use HTTPS")
 	flag.BoolVar(&disableGeoip, "disable-geoip", false, "don't use geoip for stats collection")
+
 	flag.StringVar(&metricsFilename, "metrics-log", "", "path to metrics logging output")
 	flag.BoolVar(&unsafeLogging, "unsafe-logging", false, "prevent logs from being scrubbed")
+
+	flag.StringVar(&socket, "socket", "/tmp/broker.sock", "path to ipc socket")
+
 	flag.Parse()
 
 	var err error
 	var metricsFile io.Writer
+
 	var logOutput io.Writer = os.Stderr
 	if unsafeLogging {
 		log.SetOutput(logOutput)
@@ -179,7 +171,6 @@ func main() {
 		// We want to send the log output through our scrubber first
 		log.SetOutput(&safelog.LogScrubber{Output: logOutput})
 	}
-
 	log.SetFlags(log.LstdFlags | log.LUTC)
 
 	if metricsFilename != "" {
@@ -205,21 +196,6 @@ func main() {
 
 	go ctx.Broker()
 
-	i := &IPC{ctx}
-
-	http.HandleFunc("/robots.txt", robotsTxtHandler)
-
-	http.Handle("/proxy", SnowflakeHandler{i, proxyPolls})
-	http.Handle("/client", SnowflakeHandler{i, clientOffers})
-	http.Handle("/answer", SnowflakeHandler{i, proxyAnswers})
-	http.Handle("/debug", SnowflakeHandler{i, debugHandler})
-	http.Handle("/metrics", MetricsHandler{metricsFilename, metricsHandler})
-	http.Handle("/prometheus", promhttp.HandlerFor(ctx.metrics.promMetrics.registry, promhttp.HandlerOpts{}))
-
-	server := http.Server{
-		Addr: addr,
-	}
-
 	sigChan := make(chan os.Signal, 1)
 	signal.Notify(sigChan, syscall.SIGHUP)
 
@@ -236,49 +212,18 @@ func main() {
 		}
 	}()
 
-	// Handle the various ways of setting up TLS. The legal configurations
-	// are:
-	//   --acme-hostnames (with optional --acme-email and/or --acme-cert-cache)
-	//   --cert and --key together
-	//   --disable-tls
-	// The outputs of this block of code are the disableTLS,
-	// needHTTP01Listener, certManager, and getCertificate variables.
-	if acmeHostnamesCommas != "" {
-		acmeHostnames := strings.Split(acmeHostnamesCommas, ",")
-		log.Printf("ACME hostnames: %q", acmeHostnames)
+	// if err := os.RemoveAll(socket); err != nil {
+	// 	log.Fatal(err)
+	// }
 
-		var cache autocert.Cache
-		if err = os.MkdirAll(acmeCertCacheDir, 0700); err != nil {
-			log.Printf("Warning: Couldn't create cache directory %q (reason: %s) so we're *not* using our certificate cache.", acmeCertCacheDir, err)
-		} else {
-			cache = autocert.DirCache(acmeCertCacheDir)
-		}
-
-		certManager := autocert.Manager{
-			Cache:      cache,
-			Prompt:     autocert.AcceptTOS,
-			HostPolicy: autocert.HostWhitelist(acmeHostnames...),
-			Email:      acmeEmail,
-		}
-		go func() {
-			log.Printf("Starting HTTP-01 listener")
-			log.Fatal(http.ListenAndServe(":80", certManager.HTTPHandler(nil)))
-		}()
-
-		server.TLSConfig = &tls.Config{GetCertificate: certManager.GetCertificate}
-		err = server.ListenAndServeTLS("", "")
-	} else if certFilename != "" && keyFilename != "" {
-		if acmeEmail != "" || acmeHostnamesCommas != "" {
-			log.Fatalf("The --cert and --key options are not allowed with --acme-email or --acme-hostnames.")
-		}
-		err = server.ListenAndServeTLS(certFilename, keyFilename)
-	} else if disableTLS {
-		err = server.ListenAndServe()
-	} else {
-		log.Fatal("the --acme-hostnames, --cert and --key, or --disable-tls option is required")
-	}
+	ipc := &IPC{ctx}
+	rpc.Register(ipc)
 
+	l, err := net.Listen("unix", socket)
 	if err != nil {
 		log.Fatal(err)
 	}
+	defer l.Close()
+
+	rpc.Accept(l)
 }