private void UpdateRuntimeRoutes(DynamicConfigRoot config)
{
var desiredRoutes = new HashSet <string>(StringComparer.Ordinal);
var changed = false;
foreach (var configRoute in config.Routes)
{
desiredRoutes.Add(configRoute.RouteId);
// Note that this can be null, and that is fine. The resulting route may match
// but would then fail to route, which is exactly what we were instructed to do in this case
// since no valid backend was specified.
var backendOrNull = _backendManager.TryGetItem(configRoute.BackendId);
_routeManager.GetOrCreateItem(
itemId: configRoute.RouteId,
setupAction: route =>
{
var currentRouteConfig = route.Config.Value;
if (currentRouteConfig == null ||
currentRouteConfig.HasConfigChanged(configRoute, backendOrNull))
{
// Config changed, so update runtime route
changed = true;
if (currentRouteConfig == null)
{
_logger.LogDebug("Route {routeId} has been added.", configRoute.RouteId);
}
else
{
_logger.LogDebug("Route {routeId} has changed.", configRoute.RouteId);
}
var newConfig = _routeEndpointBuilder.Build(configRoute, backendOrNull, route);
route.Config.Value = newConfig;
}
});
}
foreach (var existingRoute in _routeManager.GetItems())
{
if (!desiredRoutes.Contains(existingRoute.RouteId))
{
// NOTE 1: This is safe to do within the `foreach` loop
// because `IRouteManager.GetItems` returns a copy of the list of routes.
//
// NOTE 2: Removing the route from `IRouteManager` is safe and existing
// ASP .NET Core endpoints will continue to work with their existing behavior since
// their copy of `RouteConfig` is immutable and remains operational in whichever state is was in.
_logger.LogDebug("Route {routeId} has been removed.", existingRoute.RouteId);
_routeManager.TryRemoveItem(existingRoute.RouteId);
changed = true;
}
}
if (changed)
{
var aspNetCoreEndpoints = new List <AspNetCore.Http.Endpoint>();
foreach (var existingRoute in _routeManager.GetItems())
{
var runtimeConfig = existingRoute.Config.Value;
if (runtimeConfig?.AspNetCoreEndpoints != null)
{
aspNetCoreEndpoints.AddRange(runtimeConfig.AspNetCoreEndpoints);
}
}
// This is where the new routes take effect!
_dynamicEndpointDataSource.Update(aspNetCoreEndpoints);
}
}