Add throttled requests to metrics.

docs/prometheus-metrics.md

@@ -49,3 +49,5 @@ The following metrics are available:
 | `signaling_grpc_client_calls_total`               | Counter   | 1.0.0     | The total number of GRPC client calls                                     | `method`                          |
 | `signaling_grpc_server_calls_total`               | Counter   | 1.0.0     | The total number of GRPC server calls                                     | `method`                          |
 | `signaling_http_client_pool_connections`          | Gauge     | 1.2.4     | The current number of HTTP client connections per host                    | `host`                            |
+| `signaling_throttle_delayed_total`                | Counter   | 1.2.5     | The total number of delayed requests                                      | `action`, `delay`                 |
+| `signaling_throttle_bruteforce_total`             | Counter   | 1.2.5     | The total number of rejected bruteforce requests                          | `action`                          |

throttle.go

@@ -25,6 +25,7 @@ import (
 	"context"
 	"errors"
 	"log"
+	"strconv"
 	"sync"
 	"time"
 )
@@ -54,6 +55,10 @@ var (
 	ErrBruteforceDetected = errors.New("bruteforce detected")
 )
 
+func init() {
+	RegisterThrottleStats()
+}
+
 type ThrottleFunc func(ctx context.Context)
 
 type Throttler interface {
@@ -248,6 +253,7 @@ func (t *memoryThrottler) CheckBruteforce(ctx context.Context, client string, ac
 		delta := now.Sub(entries[l-maxBruteforceAttempts].ts)
 		if delta <= maxBruteforceDurationThreshold {
 			log.Printf("Detected bruteforce attempt on \"%s\" from %s", action, client)
+			statsThrottleBruteforceTotal.WithLabelValues(action).Inc()
 			return doThrottle, ErrBruteforceDetected
 		}
 	}
@@ -271,6 +277,7 @@ func (t *memoryThrottler) throttle(ctx context.Context, client string, action st
 	count := t.addEntry(client, action, entry)
 	delay := t.getDelay(count - 1)
 	log.Printf("Failed attempt on \"%s\" from %s, throttling by %s", action, client, delay)
+	statsThrottleDelayedTotal.WithLabelValues(action, strconv.FormatInt(delay.Milliseconds(), 10)).Inc()
 	t.doDelay(ctx, delay)
 }
 

throttle_stats_prometheus.go

@@ -0,0 +1,51 @@
+/**
+ * Standalone signaling server for the Nextcloud Spreed app.
+ * Copyright (C) 2024 struktur AG
+ *
+ * @author Joachim Bauch <bauch@struktur.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package signaling
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	statsThrottleDelayedTotal = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "signaling",
+		Subsystem: "throttle",
+		Name:      "delayed_total",
+		Help:      "The total number of delayed requests",
+	}, []string{"action", "delay"})
+
+	statsThrottleBruteforceTotal = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "signaling",
+		Subsystem: "throttle",
+		Name:      "bruteforce_total",
+		Help:      "The total number of rejected bruteforce requests",
+	}, []string{"action"})
+
+	throttleStats = []prometheus.Collector{
+		statsThrottleDelayedTotal,
+		statsThrottleBruteforceTotal,
+	}
+)
+
+func RegisterThrottleStats() {
+	registerAll(throttleStats...)
+}