Disambiguate linked host agent alert names

internal/alerts/alerts.go

@@ -2851,16 +2851,27 @@ func hostResourceID(hostID string) string {
 }
 
 func hostDisplayName(host models.Host) string {
+	base := "Host"
 	if name := strings.TrimSpace(host.DisplayName); name != "" {
-		return name
+		base = name
+	} else if name := strings.TrimSpace(host.Hostname); name != "" {
+		base = name
+	} else if host.ID != "" {
+		base = host.ID
 	}
-	if name := strings.TrimSpace(host.Hostname); name != "" {
-		return name
+
+	if strings.TrimSpace(host.LinkedNodeID) != "" ||
+		strings.TrimSpace(host.LinkedVMID) != "" ||
+		strings.TrimSpace(host.LinkedContainerID) != "" {
+		if strings.EqualFold(base, "Host") {
+			return "Host Agent"
+		}
+		if !strings.Contains(strings.ToLower(base), "host agent") {
+			return fmt.Sprintf("%s (Host Agent)", base)
+		}
 	}
-	if host.ID != "" {
-		return host.ID
-	}
-	return "Host"
+
+	return base
 }
 
 func hostInstanceName(host models.Host) string {
@@ -3067,7 +3078,7 @@ func (m *Manager) CheckHost(host models.Host) {
 				if disk.Temperature > 0 && !disk.Standby {
 					// Use specific resource ID for the disk: hostID/disk-temp:device
 					tempResourceID := fmt.Sprintf("%s/disk_temp:%s", hostResourceID(host.ID), sanitizeHostComponent(disk.Device))
-					tempResourceName := fmt.Sprintf("%s (%s Temp)", host.DisplayName, disk.Device)
+					tempResourceName := fmt.Sprintf("%s (%s Temp)", hostDisplayName(host), disk.Device)
 
 					diskTempMetadata := cloneMetadata(baseMetadata)
 					diskTempMetadata["metric"] = "diskTemperature"

internal/alerts/alerts_test.go

@@ -15021,6 +15021,39 @@ func TestCheckHostComprehensive(t *testing.T) {
 			t.Error("expected tags in metadata")
 		}
 	})
+
+	t.Run("qualifies linked host agent alert resource names", func(t *testing.T) {
+		m := newTestManager(t)
+
+		m.mu.Lock()
+		m.config.TimeThreshold = 0
+		m.config.TimeThresholds = map[string]int{}
+		m.config.HostDefaults = ThresholdConfig{
+			CPU: &HysteresisThreshold{Trigger: 80.0, Clear: 70.0},
+		}
+		m.mu.Unlock()
+
+		host := models.Host{
+			ID:          "host1",
+			DisplayName: "Hamster",
+			Hostname:    "hamster.local",
+			LinkedVMID:  "Main:node3:101",
+			CPUUsage:    97.5,
+		}
+
+		m.CheckHost(host)
+
+		m.mu.RLock()
+		alert := m.activeAlerts["host:host1-cpu"]
+		m.mu.RUnlock()
+
+		if alert == nil {
+			t.Fatal("expected CPU alert")
+		}
+		if alert.ResourceName != "Hamster (Host Agent)" {
+			t.Fatalf("expected qualified host resource name, got %q", alert.ResourceName)
+		}
+	})
 }
 
 func TestCheckPBSComprehensive(t *testing.T) {

internal/alerts/utility_test.go

@@ -710,6 +710,33 @@ func TestHostDisplayName(t *testing.T) {
 			},
 			want: "Server Name",
 		},
+		{
+			name: "linked host agent display name is qualified",
+			host: models.Host{
+				ID:          "id-123",
+				DisplayName: "Hamster",
+				LinkedVMID:  "Main:node1:101",
+			},
+			want: "Hamster (Host Agent)",
+		},
+		{
+			name: "linked host agent hostname fallback is qualified",
+			host: models.Host{
+				ID:                "id-123",
+				Hostname:          "proxmoxn3",
+				LinkedContainerID: "Main:node1:102",
+			},
+			want: "proxmoxn3 (Host Agent)",
+		},
+		{
+			name: "existing host agent suffix is not duplicated",
+			host: models.Host{
+				ID:           "id-123",
+				DisplayName:  "Hamster (Host Agent)",
+				LinkedNodeID: "Main-node1",
+			},
+			want: "Hamster (Host Agent)",
+		},
 	}
 
 	for _, tc := range tests {