func (f *frontend) rebuild() error {
settings := f.frontend.HTTPSettings()
// set up forwarder
fwd, err := forward.New(
forward.Logger(f.log),
forward.RoundTripper(f.backend.transport),
forward.Rewriter(
&forward.HeaderRewriter{
Hostname: settings.Hostname,
TrustForwardHeader: settings.TrustForwardHeader,
}),
forward.PassHostHeader(settings.PassHostHeader))
// rtwatcher will be observing and aggregating metrics
watcher, err := NewWatcher(fwd)
if err != nil {
return err
}
// Create a load balancer
rr, err := roundrobin.New(watcher)
if err != nil {
return err
}
// Rebalancer will readjust load balancer weights based on error ratios
rb, err := roundrobin.NewRebalancer(rr, roundrobin.RebalancerLogger(f.log))
if err != nil {
return err
}
// create middlewares sorted by priority and chain them
middlewares := f.sortedMiddlewares()
handlers := make([]http.Handler, len(middlewares))
for i, m := range middlewares {
var prev http.Handler
if i == 0 {
prev = rb
} else {
prev = handlers[i-1]
}
h, err := m.Middleware.NewHandler(prev)
if err != nil {
return err
}
handlers[i] = h
}
var next http.Handler
if len(handlers) != 0 {
next = handlers[len(handlers)-1]
} else {
next = rb
}
// stream will retry and replay requests, fix encodings
if settings.FailoverPredicate == "" {
settings.FailoverPredicate = `IsNetworkError() && RequestMethod() == "GET" && Attempts() < 2`
}
str, err := stream.New(next,
stream.Logger(f.log),
stream.Retry(settings.FailoverPredicate),
stream.MaxRequestBodyBytes(settings.Limits.MaxBodyBytes),
stream.MemRequestBodyBytes(settings.Limits.MaxMemBodyBytes))
if err != nil {
return err
}
if err := syncServers(f.mux, rb, f.backend, watcher); err != nil {
return err
}
// Add the frontend to the router
if err := f.mux.router.Handle(f.frontend.Route, str); err != nil {
return err
}
f.lb = rb
f.handler = str
f.watcher = watcher
return nil
}
// LoadConfig returns a new gorilla.mux Route from the specified global configuration and the dynamic
// provider configurations.
func (server *Server) loadConfig(configurations configs, globalConfiguration GlobalConfiguration) (map[string]*serverEntryPoint, error) {
serverEntryPoints := server.buildEntryPoints(globalConfiguration)
redirectHandlers := make(map[string]http.Handler)
backends := map[string]http.Handler{}
backend2FrontendMap := map[string]string{}
for _, configuration := range configurations {
frontendNames := sortedFrontendNamesForConfig(configuration)
frontend:
for _, frontendName := range frontendNames {
frontend := configuration.Frontends[frontendName]
log.Debugf("Creating frontend %s", frontendName)
fwd, err := forward.New(forward.Logger(oxyLogger), forward.PassHostHeader(frontend.PassHostHeader))
if err != nil {
log.Errorf("Error creating forwarder for frontend %s: %v", frontendName, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
saveBackend := middlewares.NewSaveBackend(fwd)
if len(frontend.EntryPoints) == 0 {
log.Errorf("No entrypoint defined for frontend %s, defaultEntryPoints:%s", frontendName, globalConfiguration.DefaultEntryPoints)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
for _, entryPointName := range frontend.EntryPoints {
log.Debugf("Wiring frontend %s to entryPoint %s", frontendName, entryPointName)
if _, ok := serverEntryPoints[entryPointName]; !ok {
log.Errorf("Undefined entrypoint '%s' for frontend %s", entryPointName, frontendName)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
newServerRoute := &serverRoute{route: serverEntryPoints[entryPointName].httpRouter.GetHandler().NewRoute().Name(frontendName)}
for routeName, route := range frontend.Routes {
err := getRoute(newServerRoute, &route)
if err != nil {
log.Errorf("Error creating route for frontend %s: %v", frontendName, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
log.Debugf("Creating route %s %s", routeName, route.Rule)
}
entryPoint := globalConfiguration.EntryPoints[entryPointName]
if entryPoint.Redirect != nil {
if redirectHandlers[entryPointName] != nil {
newServerRoute.route.Handler(redirectHandlers[entryPointName])
} else if handler, err := server.loadEntryPointConfig(entryPointName, entryPoint); err != nil {
log.Errorf("Error loading entrypoint configuration for frontend %s: %v", frontendName, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
} else {
newServerRoute.route.Handler(handler)
redirectHandlers[entryPointName] = handler
}
} else {
if backends[frontend.Backend] == nil {
log.Debugf("Creating backend %s", frontend.Backend)
var lb http.Handler
rr, _ := roundrobin.New(saveBackend)
if configuration.Backends[frontend.Backend] == nil {
log.Errorf("Undefined backend '%s' for frontend %s", frontend.Backend, frontendName)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
lbMethod, err := types.NewLoadBalancerMethod(configuration.Backends[frontend.Backend].LoadBalancer)
if err != nil {
log.Errorf("Error loading load balancer method '%+v' for frontend %s: %v", configuration.Backends[frontend.Backend].LoadBalancer, frontendName, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
stickysession := configuration.Backends[frontend.Backend].LoadBalancer.Sticky
cookiename := "_TRAEFIK_BACKEND"
var sticky *roundrobin.StickySession
if stickysession {
sticky = roundrobin.NewStickySession(cookiename)
}
switch lbMethod {
case types.Drr:
log.Debugf("Creating load-balancer drr")
rebalancer, _ := roundrobin.NewRebalancer(rr, roundrobin.RebalancerLogger(oxyLogger))
if stickysession {
log.Debugf("Sticky session with cookie %v", cookiename)
rebalancer, _ = roundrobin.NewRebalancer(rr, roundrobin.RebalancerLogger(oxyLogger), roundrobin.RebalancerStickySession(sticky))
}
lb = rebalancer
for serverName, server := range configuration.Backends[frontend.Backend].Servers {
url, err := url.Parse(server.URL)
if err != nil {
log.Errorf("Error parsing server URL %s: %v", server.URL, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
backend2FrontendMap[url.String()] = frontendName
log.Debugf("Creating server %s at %s with weight %d", serverName, url.String(), server.Weight)
if err := rebalancer.UpsertServer(url, roundrobin.Weight(server.Weight)); err != nil {
log.Errorf("Error adding server %s to load balancer: %v", server.URL, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
}
case types.Wrr:
log.Debugf("Creating load-balancer wrr")
if stickysession {
log.Debugf("Sticky session with cookie %v", cookiename)
rr, _ = roundrobin.New(saveBackend, roundrobin.EnableStickySession(sticky))
}
lb = rr
for serverName, server := range configuration.Backends[frontend.Backend].Servers {
url, err := url.Parse(server.URL)
if err != nil {
log.Errorf("Error parsing server URL %s: %v", server.URL, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
backend2FrontendMap[url.String()] = frontendName
log.Debugf("Creating server %s at %s with weight %d", serverName, url.String(), server.Weight)
if err := rr.UpsertServer(url, roundrobin.Weight(server.Weight)); err != nil {
log.Errorf("Error adding server %s to load balancer: %v", server.URL, err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
}
}
maxConns := configuration.Backends[frontend.Backend].MaxConn
if maxConns != nil && maxConns.Amount != 0 {
extractFunc, err := utils.NewExtractor(maxConns.ExtractorFunc)
if err != nil {
log.Errorf("Error creating connlimit: %v", err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
log.Debugf("Creating loadd-balancer connlimit")
lb, err = connlimit.New(lb, extractFunc, maxConns.Amount, connlimit.Logger(oxyLogger))
if err != nil {
log.Errorf("Error creating connlimit: %v", err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
}
// retry ?
if globalConfiguration.Retry != nil {
retries := len(configuration.Backends[frontend.Backend].Servers)
if globalConfiguration.Retry.Attempts > 0 {
retries = globalConfiguration.Retry.Attempts
}
lb = middlewares.NewRetry(retries, lb)
log.Debugf("Creating retries max attempts %d", retries)
}
var negroni = negroni.New()
if configuration.Backends[frontend.Backend].CircuitBreaker != nil {
log.Debugf("Creating circuit breaker %s", configuration.Backends[frontend.Backend].CircuitBreaker.Expression)
cbreaker, err := middlewares.NewCircuitBreaker(lb, configuration.Backends[frontend.Backend].CircuitBreaker.Expression, cbreaker.Logger(oxyLogger))
if err != nil {
log.Errorf("Error creating circuit breaker: %v", err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
negroni.Use(cbreaker)
} else {
negroni.UseHandler(lb)
}
backends[frontend.Backend] = negroni
} else {
log.Debugf("Reusing backend %s", frontend.Backend)
}
if frontend.Priority > 0 {
newServerRoute.route.Priority(frontend.Priority)
}
server.wireFrontendBackend(newServerRoute, backends[frontend.Backend])
}
err := newServerRoute.route.GetError()
if err != nil {
log.Errorf("Error building route: %s", err)
}
}
}
}
middlewares.SetBackend2FrontendMap(&backend2FrontendMap)
//sort routes
for _, serverEntryPoint := range serverEntryPoints {
serverEntryPoint.httpRouter.GetHandler().SortRoutes()
}
return serverEntryPoints, nil
}