package router import ( "context" "errors" "fmt" "math" "net/http" "strings" "github.com/containous/alice" "github.com/traefik/traefik/v2/pkg/config/runtime" "github.com/traefik/traefik/v2/pkg/log" "github.com/traefik/traefik/v2/pkg/metrics" "github.com/traefik/traefik/v2/pkg/middlewares/accesslog" "github.com/traefik/traefik/v2/pkg/middlewares/denyrouterrecursion" metricsMiddle "github.com/traefik/traefik/v2/pkg/middlewares/metrics" "github.com/traefik/traefik/v2/pkg/middlewares/recovery" "github.com/traefik/traefik/v2/pkg/middlewares/tracing" httpmuxer "github.com/traefik/traefik/v2/pkg/muxer/http" "github.com/traefik/traefik/v2/pkg/server/middleware" "github.com/traefik/traefik/v2/pkg/server/provider" "github.com/traefik/traefik/v2/pkg/tls" ) const maxUserPriority = math.MaxInt - 1000 type middlewareBuilder interface { BuildChain(ctx context.Context, names []string) *alice.Chain } type serviceManager interface { BuildHTTP(rootCtx context.Context, serviceName string) (http.Handler, error) LaunchHealthCheck() } // Manager A route/router manager. type Manager struct { routerHandlers map[string]http.Handler serviceManager serviceManager metricsRegistry metrics.Registry middlewaresBuilder middlewareBuilder chainBuilder *middleware.ChainBuilder conf *runtime.Configuration tlsManager *tls.Manager } // NewManager creates a new Manager. func NewManager(conf *runtime.Configuration, serviceManager serviceManager, middlewaresBuilder middlewareBuilder, chainBuilder *middleware.ChainBuilder, metricsRegistry metrics.Registry, tlsManager *tls.Manager) *Manager { return &Manager{ routerHandlers: make(map[string]http.Handler), serviceManager: serviceManager, metricsRegistry: metricsRegistry, middlewaresBuilder: middlewaresBuilder, chainBuilder: chainBuilder, conf: conf, tlsManager: tlsManager, } } func (m *Manager) getHTTPRouters(ctx context.Context, entryPoints []string, tls bool) map[string]map[string]*runtime.RouterInfo { if m.conf != nil { return m.conf.GetRoutersByEntryPoints(ctx, entryPoints, tls) } return make(map[string]map[string]*runtime.RouterInfo) } // BuildHandlers Builds handler for all entry points. func (m *Manager) BuildHandlers(rootCtx context.Context, entryPoints []string, tls bool) map[string]http.Handler { entryPointHandlers := make(map[string]http.Handler) for entryPointName, routers := range m.getHTTPRouters(rootCtx, entryPoints, tls) { ctx := log.With(rootCtx, log.Str(log.EntryPointName, entryPointName)) handler, err := m.buildEntryPointHandler(ctx, routers) if err != nil { log.FromContext(ctx).Error(err) continue } handlerWithAccessLog, err := alice.New(func(next http.Handler) (http.Handler, error) { return accesslog.NewFieldHandler(next, log.EntryPointName, entryPointName, accesslog.InitServiceFields), nil }).Then(handler) if err != nil { log.FromContext(ctx).Error(err) entryPointHandlers[entryPointName] = handler } else { entryPointHandlers[entryPointName] = handlerWithAccessLog } } for _, entryPointName := range entryPoints { ctx := log.With(rootCtx, log.Str(log.EntryPointName, entryPointName)) handler, ok := entryPointHandlers[entryPointName] if !ok || handler == nil { handler = BuildDefaultHTTPRouter() } handlerWithMiddlewares, err := m.chainBuilder.Build(ctx, entryPointName).Then(handler) if err != nil { log.FromContext(ctx).Error(err) continue } entryPointHandlers[entryPointName] = handlerWithMiddlewares } return entryPointHandlers } func (m *Manager) buildEntryPointHandler(ctx context.Context, configs map[string]*runtime.RouterInfo) (http.Handler, error) { muxer, err := httpmuxer.NewMuxer() if err != nil { return nil, err } for routerName, routerConfig := range configs { ctxRouter := log.With(provider.AddInContext(ctx, routerName), log.Str(log.RouterName, routerName)) logger := log.FromContext(ctxRouter) if routerConfig.Priority > maxUserPriority && !strings.HasSuffix(routerName, "@internal") { err = fmt.Errorf("the router priority %d exceeds the max user-defined priority %d", routerConfig.Priority, maxUserPriority) routerConfig.AddError(err, true) logger.Error(err) continue } handler, err := m.buildRouterHandler(ctxRouter, routerName, routerConfig) if err != nil { routerConfig.AddError(err, true) logger.Error(err) continue } err = muxer.AddRoute(routerConfig.Rule, routerConfig.Priority, handler) if err != nil { routerConfig.AddError(err, true) logger.Error(err) continue } } muxer.SortRoutes() chain := alice.New() chain = chain.Append(func(next http.Handler) (http.Handler, error) { return recovery.New(ctx, next) }) return chain.Then(muxer) } func (m *Manager) buildRouterHandler(ctx context.Context, routerName string, routerConfig *runtime.RouterInfo) (http.Handler, error) { if handler, ok := m.routerHandlers[routerName]; ok { return handler, nil } if routerConfig.TLS != nil { // Don't build the router if the TLSOptions configuration is invalid. tlsOptionsName := tls.DefaultTLSConfigName if len(routerConfig.TLS.Options) > 0 && routerConfig.TLS.Options != tls.DefaultTLSConfigName { tlsOptionsName = provider.GetQualifiedName(ctx, routerConfig.TLS.Options) } if _, err := m.tlsManager.Get(tls.DefaultTLSStoreName, tlsOptionsName); err != nil { return nil, fmt.Errorf("building router handler: %w", err) } } handler, err := m.buildHTTPHandler(ctx, routerConfig, routerName) if err != nil { return nil, err } handlerWithAccessLog, err := alice.New(func(next http.Handler) (http.Handler, error) { return accesslog.NewFieldHandler(next, accesslog.RouterName, routerName, nil), nil }).Then(handler) if err != nil { log.FromContext(ctx).Error(err) m.routerHandlers[routerName] = handler } else { m.routerHandlers[routerName] = handlerWithAccessLog } return m.routerHandlers[routerName], nil } func (m *Manager) buildHTTPHandler(ctx context.Context, router *runtime.RouterInfo, routerName string) (http.Handler, error) { var qualifiedNames []string for _, name := range router.Middlewares { qualifiedNames = append(qualifiedNames, provider.GetQualifiedName(ctx, name)) } router.Middlewares = qualifiedNames if router.Service == "" { return nil, errors.New("the service is missing on the router") } sHandler, err := m.serviceManager.BuildHTTP(ctx, router.Service) if err != nil { return nil, err } mHandler := m.middlewaresBuilder.BuildChain(ctx, router.Middlewares) tHandler := func(next http.Handler) (http.Handler, error) { return tracing.NewForwarder(ctx, routerName, router.Service, next), nil } chain := alice.New() if m.metricsRegistry != nil && m.metricsRegistry.IsRouterEnabled() { chain = chain.Append(metricsMiddle.WrapRouterHandler(ctx, m.metricsRegistry, routerName, provider.GetQualifiedName(ctx, router.Service))) } if router.DefaultRule { chain = chain.Append(denyrouterrecursion.WrapHandler(routerName)) } return chain.Extend(*mHandler).Append(tHandler).Then(sHandler) } // BuildDefaultHTTPRouter creates a default HTTP router. func BuildDefaultHTTPRouter() http.Handler { return http.NotFoundHandler() }