private async Task <(IList <ProxyRoute>, IList <Exception>)> VerifyRoutesAsync(IReadOnlyList <ProxyRoute> routes, CancellationToken cancellation)
{
if (routes == null)
{
return(Array.Empty <ProxyRoute>(), Array.Empty <Exception>());
}
var seenRouteIds = new HashSet <string>();
var sortedRoutes = new SortedList <(int, string), ProxyRoute>(routes?.Count ?? 0);
var errors = new List <Exception>();
foreach (var r in routes)
{
if (seenRouteIds.Contains(r.RouteId))
{
errors.Add(new ArgumentException($"Duplicate route {r.RouteId}"));
continue;
}
// Don't modify the original
var route = r.DeepClone();
try
{
foreach (var filter in _filters)
{
await filter.ConfigureRouteAsync(route, cancellation);
}
}
catch (Exception ex)
{
errors.Add(new Exception($"An exception was thrown from the configuration callbacks for route '{r.RouteId}'.", ex));
continue;
}
var routeErrors = await _configValidator.ValidateRouteAsync(route);
if (routeErrors.Count > 0)
{
errors.AddRange(routeErrors);
continue;
}
sortedRoutes.Add((route.Order ?? 0, route.RouteId), route);
}
if (errors.Count > 0)
{
return(null, errors);
}
return(sortedRoutes.Values, errors);
}
/// <inheritdoc/>
public async Task <(IReadOnlyList <RouteConfig> Routes, IReadOnlyList <ClusterConfig> Clusters)> DiscoverAsync(CancellationToken cancellation)
{
// Take a snapshot of current options and use that consistently for this execution.
var options = _optionsMonitor.CurrentValue;
_serviceFabricCaller.CleanUpExpired();
var discoveredBackends = new Dictionary <string, ClusterConfig>(StringComparer.Ordinal);
var discoveredRoutes = new List <RouteConfig>();
IEnumerable <ApplicationWrapper> applications;
try
{
applications = await _serviceFabricCaller.GetApplicationListAsync(cancellation);
}
catch (OperationCanceledException) when(cancellation.IsCancellationRequested)
{
throw;
}
catch (Exception ex) // TODO: davidni: not fatal?
{
// The serviceFabricCaller does their best effort to use LKG information, nothing we can do at this point
Log.GettingApplicationFailed(_logger, ex);
applications = Enumerable.Empty <ApplicationWrapper>();
}
foreach (var application in applications)
{
IEnumerable <ServiceWrapper> services;
try
{
services = await _serviceFabricCaller.GetServiceListAsync(application.ApplicationName, cancellation);
}
catch (OperationCanceledException) when(cancellation.IsCancellationRequested)
{
throw;
}
catch (Exception ex) // TODO: davidni: not fatal?
{
Log.GettingServiceFailed(_logger, application.ApplicationName, ex);
continue;
}
foreach (var service in services)
{
try
{
var serviceExtensionLabels = await _serviceFabricExtensionConfigProvider.GetExtensionLabelsAsync(application, service, cancellation);
// If this service wants to use us as the proxy
if (serviceExtensionLabels.GetValueOrDefault("YARP.Enable", null) != "true")
{
// Skip this service
continue;
}
var destinations = await DiscoverDestinationsAsync(options, service, serviceExtensionLabels, cancellation);
var cluster = LabelsParser.BuildCluster(service.ServiceName, serviceExtensionLabels, destinations);
var clusterValidationErrors = await _configValidator.ValidateClusterAsync(cluster);
if (clusterValidationErrors.Count > 0)
{
throw new ConfigException($"Skipping cluster id '{cluster.ClusterId} due to validation errors.", new AggregateException(clusterValidationErrors));
}
if (!discoveredBackends.TryAdd(cluster.ClusterId, cluster))
{
throw new ConfigException($"Duplicated cluster id '{cluster.ClusterId}'. Skipping repeated definition, service '{service.ServiceName}'");
}
var routes = LabelsParser.BuildRoutes(service.ServiceName, serviceExtensionLabels);
var routeValidationErrors = new List <Exception>();
foreach (var route in routes)
{
routeValidationErrors.AddRange(await _configValidator.ValidateRouteAsync(route));
}
if (routeValidationErrors.Count > 0)
{
// Don't add ANY routes if even a single one is bad. Trying to add partial routes
// could lead to unexpected results (e.g. a typo in the configuration of higher-priority route
// could lead to a lower-priority route being selected for requests it should not be handling).
throw new ConfigException($"Skipping ALL routes for cluster id '{cluster.ClusterId} due to validation errors.", new AggregateException(routeValidationErrors));
}
discoveredRoutes.AddRange(routes);
ReportServiceHealth(options, service.ServiceName, HealthState.Ok, $"Successfully built cluster '{cluster.ClusterId}' with {routes.Count} routes.");
}
catch (ConfigException ex)
{
// User error
Log.InvalidServiceConfig(_logger, service.ServiceName, ex);
// TODO: emit Error health report once we are able to detect config issues *during* (as opposed to *after*) a target service upgrade.
// Proactive Error health report would trigger a rollback of the target service as desired. However, an Error report after rhe fact
// will NOT cause a rollback and will prevent the target service from performing subsequent monitored upgrades to mitigate, making things worse.
ReportServiceHealth(options, service.ServiceName, HealthState.Warning, $"Could not load service configuration: {ex.Message}.");
}
catch (Exception ex) // TODO: davidni: not fatal?
{
// Not user's problem
Log.ErrorLoadingServiceConfig(_logger, service.ServiceName, ex);
}
}
}
Log.ServiceDiscovered(_logger, discoveredBackends.Count, discoveredRoutes.Count);
return(discoveredRoutes, discoveredBackends.Values.ToList());
}
