Track memory used by DoH buffers (#72)

integration_test.go

@@ -44,7 +44,14 @@ func TestIntegration(t *testing.T) {
 	}
 
 	// Check some expected metrics are present
-	for _, metric := range []string{"go_info", "unbound_queries_total", "unbound_response_time_seconds", "unbound_cache_hits_total"} {
+	for _, metric := range []string{
+		"go_info",
+		"unbound_queries_total",
+		"unbound_response_time_seconds",
+		"unbound_cache_hits_total",
+		"unbound_query_https_total",
+		"unbound_memory_doh_bytes",
+	} {
 		if _, ok := metrics[metric]; !ok {
 			t.Errorf("Expected metric is missing: %s", metric)
 		}

unbound_exporter.go

@@ -196,7 +196,7 @@ var (
 			"^num\\.query\\.tls\\.resume$"),
 		newUnboundMetric(
 			"query_https_total",
-			"Total number of queries that were made using HTTPS towards the Unbound server.",
+			"Total number of DoH queries that were made towards the Unbound server.",
 			prometheus.CounterValue,
 			nil,
 			"^num\\.query\\.https$"),
@@ -325,8 +325,13 @@ var (
 			"Total number of triggered Response Policy Zone actions, by type.",
 			prometheus.CounterValue,
 			[]string{"type"},
-			"^num\\.rpz\\.action\\.rpz-([\\w-]+)$",
-		),
+			"^num\\.rpz\\.action\\.rpz-([\\w-]+)$"),
+		newUnboundMetric(
+			"memory_doh_bytes",
+			"Memory used by DoH buffers, in bytes.",
+			prometheus.GaugeValue,
+			[]string{"buffer"},
+			"^mem\\.http\\.(\\w+)$"),
 	}
 )