feat: scan host LAN web devices via proxy

internal/webdevice/service_test.go

@@ -39,7 +39,7 @@ func TestWebDeviceForwardPort(t *testing.T) {
 	}
 }
 
-func TestScanBuildsDirectURLAndAllowList(t *testing.T) {
+func TestScanBuildsProxyURLAndAllowList(t *testing.T) {
 	t.Parallel()
 
 	svc := NewService()
@@ -68,8 +68,11 @@ func TestScanBuildsDirectURLAndAllowList(t *testing.T) {
 	if !svc.IsAllowed("192.168.1.124") {
 		t.Fatal("expected IP to be allowed after scan")
 	}
-	if result.Devices[0].DirectURL != "http://10.8.0.14:31124/" {
-		t.Fatalf("DirectURL = %q", result.Devices[0].DirectURL)
+	if result.Devices[0].ProxyURL != "/proxy/web/192.168.1.124/" {
+		t.Fatalf("ProxyURL = %q", result.Devices[0].ProxyURL)
+	}
+	if result.Devices[0].DirectURL != "" {
+		t.Fatalf("DirectURL = %q, want empty", result.Devices[0].DirectURL)
 	}
 }
 
@@ -77,6 +80,7 @@ func TestScanIncludesPrivateRequestHostSubnet(t *testing.T) {
 	t.Parallel()
 
 	svc := NewService()
+	svc.hostLANGetter = nil
 	svc.interfaceGetter = func() ([]InterfaceInfo, error) {
 		return []InterfaceInfo{{
 			Name:    "eth0",
@@ -113,6 +117,75 @@ func TestScanIncludesPrivateRequestHostSubnet(t *testing.T) {
 	}
 }
 
+func TestScanPrefersHostLANInterfaces(t *testing.T) {
+	t.Parallel()
+
+	svc := NewService()
+	svc.interfaceGetter = func() ([]InterfaceInfo, error) {
+		return []InterfaceInfo{{
+			Name:    "eth0",
+			IP:      "172.20.0.4",
+			Netmask: "255.255.0.0",
+		}}, nil
+	}
+	svc.hostLANGetter = func() ([]InterfaceInfo, error) {
+		return []InterfaceInfo{{
+			Name:    "eno1",
+			IP:      "192.168.0.117",
+			Netmask: "255.255.255.0",
+		}}, nil
+	}
+	svc.tcpScanner = func(ip, netmask string, port int, excludeIPs map[string]bool) ([]TCPDevice, error) {
+		if ip != "192.168.0.117" {
+			t.Fatalf("scan ip = %q, want host LAN ip", ip)
+		}
+		if netmask != "255.255.255.0" {
+			t.Fatalf("netmask = %q, want 255.255.255.0", netmask)
+		}
+		if !excludeIPs["172.20.0.4"] || !excludeIPs["192.168.0.117"] {
+			t.Fatalf("excludeIPs = %#v, want container and host IPs", excludeIPs)
+		}
+		return []TCPDevice{{IP: "192.168.0.108", Port: 80}}, nil
+	}
+	svc.newForwarder = func(ip string, port int, listenAddress, targetAddress string) (*webDeviceForwarder, error) {
+		return &webDeviceForwarder{ip: ip, port: port, targetAddress: targetAddress}, nil
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "http://10.8.0.18:13000/api/web-devices/scan", nil)
+	result, err := svc.Scan(req)
+	if err != nil {
+		t.Fatalf("Scan() error = %v", err)
+	}
+	if result.Count != 1 {
+		t.Fatalf("result.Count = %d, want 1", result.Count)
+	}
+	if result.Devices[0].Interface != "eno1" {
+		t.Fatalf("Interface = %q, want eno1", result.Devices[0].Interface)
+	}
+}
+
+func TestParseHostLANInterfacesFiltersVirtualInterfaces(t *testing.T) {
+	t.Parallel()
+
+	output := `2: eno1    inet 192.168.0.117/24 brd 192.168.0.255 scope global eno1
+3: docker0    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
+4: tun0    inet 10.8.0.18/24 scope global tun0
+5: wlan0    inet 192.168.5.10/23 brd 192.168.5.255 scope global wlan0
+`
+
+	interfaces := parseHostLANInterfaces(output)
+
+	if len(interfaces) != 2 {
+		t.Fatalf("len(interfaces) = %d, want 2: %#v", len(interfaces), interfaces)
+	}
+	if interfaces[0].Name != "eno1" || interfaces[0].IP != "192.168.0.117" || interfaces[0].Netmask != "255.255.255.0" {
+		t.Fatalf("interfaces[0] = %#v", interfaces[0])
+	}
+	if interfaces[1].Name != "wlan0" || interfaces[1].IP != "192.168.5.10" || interfaces[1].Netmask != "255.255.254.0" {
+		t.Fatalf("interfaces[1] = %#v", interfaces[1])
+	}
+}
+
 func TestCalculateIPRangeCapsLargeSubnetToLocal24(t *testing.T) {
 	t.Parallel()