Add backup maintenance and guest update controls

network_test.go

@@ -3,6 +3,7 @@ package main
 import (
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 )
 
@@ -33,6 +34,26 @@ func TestReadNetworkSnapshot(t *testing.T) {
 	}
 }
 
+func TestExplainNetworkHealthDistinguishesDNSFailure(t *testing.T) {
+	health := NetworkHealth{Gateway: "192.168.0.1", GatewayUp: true, InternetUp: true, DNSUp: false}
+	explainNetworkHealth(&health, nil)
+	if !strings.Contains(health.Summary, "DNS") || health.RecommendedAction == "" {
+		t.Fatalf("непонятная диагностика: %+v", health)
+	}
+}
+
+func TestExplainNetworkHealthIgnoresOldInterfaceCounters(t *testing.T) {
+	health := NetworkHealth{Gateway: "192.168.0.1", GatewayUp: true, InternetUp: true, DNSUp: true}
+	explainNetworkHealth(&health, []NetworkInterface{{Name: "eno1", Carrier: true, State: "up", ReceiveDrops: 42}})
+	if health.Summary != "Сеть работает штатно" {
+		t.Fatalf("старый накопленный счётчик вызвал текущую тревогу: %+v", health)
+	}
+	explainNetworkHealth(&health, []NetworkInterface{{Name: "eno1", Carrier: true, State: "up", ReceiveDrops: 43, NewDrops: 1}})
+	if !strings.Contains(health.Summary, "последний интервал") {
+		t.Fatalf("рост счётчика не объяснён: %+v", health)
+	}
+}
+
 func TestInterfaceVMID(t *testing.T) {
 	for name, want := range map[string]int{"tap100i0": 100, "veth108i0": 108, "fwbr113i0": 113, "vmbr0": 0, "enp6s0": 0} {
 		if got := interfaceVMID(name); got != want {