func new(c *C, p string) (*roundrobin.RoundRobin, *Streamer) {
logger := utils.NewFileLogger(os.Stdout, utils.INFO)
// forwarder will proxy the request to whatever destination
fwd, err := forward.New(forward.Logger(logger))
c.Assert(err, IsNil)
// load balancer will round robin request
lb, err := roundrobin.New(fwd)
c.Assert(err, IsNil)
// stream handler will forward requests to redirect, make sure it uses files
st, err := New(lb, Logger(logger), Retry(p), MemRequestBodyBytes(1))
c.Assert(err, IsNil)
return lb, st
}
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
}