Sync OpenVPN OAuth gateway routes on tunnel changes

backend/internal/api/identity_gateway_test.go

@@ -0,0 +1,39 @@
+package api
+
+import (
+	"testing"
+
+	"vpn-platform/backend/internal/model"
+	"vpn-platform/backend/internal/store"
+)
+
+func TestAuthGatewayPortFollowsRunningOIDCTunnel(t *testing.T) {
+	oldDB := store.DB
+	t.Cleanup(func() { store.DB = oldDB })
+	if err := store.Init(t.TempDir()); err != nil {
+		t.Fatal(err)
+	}
+	line := model.Tunnel{Name: "oauth-line", Protocol: "openvpn", State: "stopped", Config: `{"auth_mode":"oidc","oidc_base_url":"https://vpn.example.com","oidc_http_port":19090}`}
+	if err := store.DB.Create(&line).Error; err != nil {
+		t.Fatal(err)
+	}
+	check := func(want int) {
+		t.Helper()
+		got, err := authGatewayPort("vpn.example.com")
+		if err != nil || got != want {
+			t.Fatalf("gateway port = %d, %v; want %d", got, err, want)
+		}
+	}
+	check(0)
+	if err := store.DB.Model(&line).Update("state", "running").Error; err != nil {
+		t.Fatal(err)
+	}
+	check(19090)
+	if port, err := authGatewayPort("other.example.com"); err != nil || port != 0 {
+		t.Fatalf("wrong domain routed: %d, %v", port, err)
+	}
+	if err := store.DB.Model(&line).Update("state", "stopped").Error; err != nil {
+		t.Fatal(err)
+	}
+	check(0)
+}