cmd/strelaypoolsrv: More compact response, improved metrics

cmd/strelaypoolsrv/gui/index.html

@@ -259,7 +259,7 @@
       return a.value > b.value ? 1 : -1;
     }
 
-    $http.get("/endpoint").then(function(response) {
+    $http.get("/endpoint/full").then(function(response) {
       $scope.relays = response.data.relays;
 
       angular.forEach($scope.relays, function(relay) {

cmd/strelaypoolsrv/main.go

@@ -27,9 +27,7 @@ import (
 	"github.com/syncthing/syncthing/lib/assets"
 	_ "github.com/syncthing/syncthing/lib/automaxprocs"
 	"github.com/syncthing/syncthing/lib/geoip"
-	"github.com/syncthing/syncthing/lib/httpcache"
 	"github.com/syncthing/syncthing/lib/protocol"
-	"github.com/syncthing/syncthing/lib/rand"
 	"github.com/syncthing/syncthing/lib/relay/client"
 	"github.com/syncthing/syncthing/lib/sync"
 	"github.com/syncthing/syncthing/lib/tlsutil"
@@ -51,6 +49,10 @@ type relay struct {
 	StatsRetrieved time.Time `json:"statsRetrieved"`
 }
 
+type relayShort struct {
+	URL string `json:"url"`
+}
+
 type stats struct {
 	StartTime          time.Time `json:"startTime"`
 	UptimeSeconds      int       `json:"uptimeSeconds"`
@@ -95,6 +97,7 @@ var (
 	testCert          tls.Certificate
 	knownRelaysFile   = filepath.Join(os.TempDir(), "strelaypoolsrv_known_relays")
 	listen            = ":80"
+	metricsListen     = ":8081"
 	dir               string
 	evictionTime      = time.Hour
 	debug             bool
@@ -125,6 +128,7 @@ func main() {
 	log.SetFlags(log.Lshortfile)
 
 	flag.StringVar(&listen, "listen", listen, "Listen address")
+	flag.StringVar(&metricsListen, "metrics-listen", metricsListen, "Metrics listen address")
 	flag.StringVar(&dir, "keys", dir, "Directory where http-cert.pem and http-key.pem is stored for TLS listening")
 	flag.BoolVar(&debug, "debug", debug, "Enable debug output")
 	flag.DurationVar(&evictionTime, "eviction", evictionTime, "After how long the relay is evicted")
@@ -218,15 +222,40 @@ func main() {
 		log.Fatalln("listen:", err)
 	}
 
-	handler := http.NewServeMux()
-	handler.HandleFunc("/", handleAssets)
-	handler.Handle("/endpoint", httpcache.SinglePath(http.HandlerFunc(handleRequest), 15*time.Second))
-	handler.HandleFunc("/metrics", handleMetrics)
+	if metricsListen != "" {
+		mmux := http.NewServeMux()
+		mmux.HandleFunc("/metrics", handleMetrics)
+		go func() {
+			if err := http.ListenAndServe(metricsListen, mmux); err != nil {
+				log.Fatalln("HTTP serve metrics:", err)
+			}
+		}()
+	}
+
+	getMux := http.NewServeMux()
+	getMux.HandleFunc("/", handleAssets)
+	getMux.HandleFunc("/endpoint", withAPIMetrics(handleEndpointShort))
+	getMux.HandleFunc("/endpoint/full", withAPIMetrics(handleEndpointFull))
+
+	postMux := http.NewServeMux()
+	postMux.HandleFunc("/endpoint", withAPIMetrics(handleRegister))
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.Method {
+		case http.MethodGet, http.MethodHead, http.MethodOptions:
+			getMux.ServeHTTP(w, r)
+		case http.MethodPost:
+			postMux.ServeHTTP(w, r)
+		default:
+			http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		}
+	})
 
 	srv := http.Server{
 		Handler:     handler,
 		ReadTimeout: 10 * time.Second,
 	}
+	srv.SetKeepAlivesEnabled(false)
 
 	err = srv.Serve(listener)
 	if err != nil {
@@ -260,39 +289,24 @@ func handleAssets(w http.ResponseWriter, r *http.Request) {
 	assets.Serve(w, r, as)
 }
 
-func handleRequest(w http.ResponseWriter, r *http.Request) {
+func withAPIMetrics(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
 		timer := prometheus.NewTimer(apiRequestsSeconds.WithLabelValues(r.Method))
-
 		w = NewLoggingResponseWriter(w)
 		defer func() {
 			timer.ObserveDuration()
 			lw := w.(*loggingResponseWriter)
 			apiRequestsTotal.WithLabelValues(r.Method, strconv.Itoa(lw.statusCode)).Inc()
 		}()
-
-	if ipHeader != "" {
-		hdr := r.Header.Get(ipHeader)
-		fields := strings.Split(hdr, ",")
-		if len(fields) > 0 {
-			r.RemoteAddr = strings.TrimSpace(fields[len(fields)-1])
-		}
-	}
-	w.Header().Set("Access-Control-Allow-Origin", "*")
-	switch r.Method {
-	case "GET":
-		handleGetRequest(w, r)
-	case "POST":
-		handlePostRequest(w, r)
-	default:
-		if debug {
-			log.Println("Unhandled HTTP method", r.Method)
-		}
-		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+		next(w, r)
 	}
 }
 
-func handleGetRequest(rw http.ResponseWriter, r *http.Request) {
+// handleEndpointFull returns the relay list with full metadata and
+// statistics. Large, and expensive.
+func handleEndpointFull(rw http.ResponseWriter, r *http.Request) {
 	rw.Header().Set("Content-Type", "application/json; charset=utf-8")
+	rw.Header().Set("Access-Control-Allow-Origin", "*")
 
 	mut.RLock()
 	relays := make([]*relay, len(permanentRelays)+len(knownRelays))
@@ -300,17 +314,38 @@ func handleGetRequest(rw http.ResponseWriter, r *http.Request) {
 	copy(relays[n:], knownRelays)
 	mut.RUnlock()
 
-	// Shuffle
-	rand.Shuffle(relays)
-
 	_ = json.NewEncoder(rw).Encode(map[string][]*relay{
 		"relays": relays,
 	})
 }
 
-func handlePostRequest(w http.ResponseWriter, r *http.Request) {
+// handleEndpointShort returns the relay list with only the URL.
+func handleEndpointShort(rw http.ResponseWriter, r *http.Request) {
+	rw.Header().Set("Content-Type", "application/json; charset=utf-8")
+	rw.Header().Set("Access-Control-Allow-Origin", "*")
+
+	mut.RLock()
+	relays := make([]relayShort, 0, len(permanentRelays)+len(knownRelays))
+	for _, r := range append(permanentRelays, knownRelays...) {
+		relays = append(relays, relayShort{URL: slimURL(r.URL)})
+	}
+	mut.RUnlock()
+
+	_ = json.NewEncoder(rw).Encode(map[string][]relayShort{
+		"relays": relays,
+	})
+}
+
+func handleRegister(w http.ResponseWriter, r *http.Request) {
 	// Get the IP address of the client
 	rhost := r.RemoteAddr
+	if ipHeader != "" {
+		hdr := r.Header.Get(ipHeader)
+		fields := strings.Split(hdr, ",")
+		if len(fields) > 0 {
+			rhost = strings.TrimSpace(fields[len(fields)-1])
+		}
+	}
 	if host, _, err := net.SplitHostPort(rhost); err == nil {
 		rhost = host
 	}
@@ -660,3 +695,16 @@ func (b *errorTracker) IsBlocked(host string) bool {
 	}
 	return false
 }
+
+func slimURL(u string) string {
+	p, err := url.Parse(u)
+	if err != nil {
+		return u
+	}
+	newQuery := url.Values{}
+	if id := p.Query().Get("id"); id != "" {
+		newQuery.Set("id", id)
+	}
+	p.RawQuery = newQuery.Encode()
+	return p.String()
+}

cmd/strelaypoolsrv/main_test.go

@@ -42,7 +42,7 @@ func TestHandleGetRequest(t *testing.T) {
 
 	w := httptest.NewRecorder()
 	w.Body = new(bytes.Buffer)
-	handleGetRequest(w, httptest.NewRequest("GET", "/", nil))
+	handleEndpointFull(w, httptest.NewRequest("GET", "/", nil))
 
 	result := make(map[string][]*relay)
 	err := json.NewDecoder(w.Body).Decode(&result)
@@ -92,3 +92,18 @@ func TestCanonicalizeQueryValues(t *testing.T) {
 		t.Errorf("expected %q, got %q", exp, str)
 	}
 }
+
+func TestSlimURL(t *testing.T) {
+	cases := []struct {
+		in, out string
+	}{
+		{"http://example.com/", "http://example.com/"},
+		{"relay://192.0.2.42:22067/?globalLimitBps=0&id=EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M&networkTimeout=2m0s&pingInterval=1m0s&providedBy=Test&sessionLimitBps=0&statusAddr=%3A22070", "relay://192.0.2.42:22067/?id=EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M-EIC6B3M"},
+	}
+
+	for _, c := range cases {
+		if got := slimURL(c.in); got != c.out {
+			t.Errorf("expected %q, got %q", c.out, got)
+		}
+	}
+}

cmd/strelaypoolsrv/stats.go

@@ -6,27 +6,12 @@ import (
 	"encoding/json"
 	"net"
 	"net/http"
-	"os"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/syncthing/syncthing/lib/sync"
 )
 
-func init() {
-	processCollectorOpts := collectors.ProcessCollectorOpts{
-		Namespace: "syncthing_relaypoolsrv",
-		PidFn: func() (int, error) {
-			return os.Getpid(), nil
-		},
-	}
-
-	prometheus.MustRegister(
-		collectors.NewProcessCollector(processCollectorOpts),
-	)
-}
-
 var (
 	statusClient = http.Client{
 		Timeout: 5 * time.Second,