// Round trips the request to one of the endpoints and returns the response.
func (l *HttpLocation) RoundTrip(req request.Request) (*http.Response, error) {
// Get options and transport as one single read transaction.
// Options and transport may change if someone calls SetOptions
o, tr := l.GetOptionsAndTransport()
originalRequest := req.GetHttpRequest()
// Check request size first, if that exceeds the limit, we don't bother reading the request.
if l.isRequestOverLimit(req) {
return nil, errors.FromStatus(http.StatusRequestEntityTooLarge)
}
// Read the body while keeping this location's limits in mind. This reader controls the maximum bytes
// to read into memory and disk. This reader returns anerror if the total request size exceeds the
// prefefined MaxSizeBytes. This can occur if we got chunked request, in this case ContentLength would be set to -1
// and the reader would be unbounded bufio in the http.Server
body, err := netutils.NewBodyBufferWithOptions(originalRequest.Body, netutils.BodyBufferOptions{
MemBufferBytes: o.Limits.MaxMemBodyBytes,
MaxSizeBytes: o.Limits.MaxBodyBytes,
})
if err != nil {
return nil, err
}
if body == nil {
return nil, fmt.Errorf("Empty body")
}
// Set request body to buffered reader that can replay the read and execute Seek
req.SetBody(body)
// Note that we don't change the original request Body as it's handled by the http server
defer body.Close()
for {
_, err := req.GetBody().Seek(0, 0)
if err != nil {
return nil, err
}
endpoint, err := l.loadBalancer.NextEndpoint(req)
if err != nil {
log.Errorf("Load Balancer failure: %s", err)
return nil, err
}
// Adds headers, changes urls. Note that we rewrite request each time we proxy it to the
// endpoint, so that each try gets a fresh start
req.SetHttpRequest(l.copyRequest(originalRequest, req.GetBody(), endpoint))
// In case if error is not nil, we allow load balancer to choose the next endpoint
// e.g. to do request failover. Nil error means that we got proxied the request successfully.
response, err := l.proxyToEndpoint(tr, &o, endpoint, req)
if o.ShouldFailover(req) {
continue
} else {
return response, err
}
}
log.Errorf("All endpoints failed!")
return nil, fmt.Errorf("All endpoints failed")
}
// RegisterApp adds a new backend and a single server with Vulcand.
func (s *LeaderRegistry) RegisterApp(registration *AppRegistration) error {
log.Infof("Registering app: %v", registration)
endpoint, err := vulcan.NewEndpointWithID(s.Group, registration.Name, registration.Host, registration.Port)
if err != nil {
return err
}
err = s.client.RegisterBackend(endpoint)
if err != nil {
log.Errorf("Failed to register backend for endpoint: %v, %s", endpoint, err)
return err
}
if s.IsMaster {
err = s.maintainLeader(endpoint)
} else {
err = s.initLeader(endpoint)
}
if err != nil {
log.Errorf("Failed to register server for endpoint: %v, %s", endpoint, err)
return err
}
return nil
}
func getFileFromUpstream(fileURL string, useSSL bool) (body []byte, statusCode int, err error) {
// Try to fetch the image. If not, fail.
url := fileURL
if useSSL {
url = fmt.Sprintf("https://%s", url)
} else {
url = fmt.Sprintf("http://%s", url)
}
resp, e := http.Get(url)
if e != nil {
err = e
log.Errorf("Couldn't get %s", url)
statusCode = 500
return
}
defer resp.Body.Close()
// Make sure the request succeeded
if resp.StatusCode > 302 {
log.Errorf("Couldn't fetch %s", url)
statusCode = resp.StatusCode
return
}
body, err = ioutil.ReadAll(resp.Body)
if err != nil {
log.Errorf("Couldn't read body %s", url)
statusCode = 500
}
return
}
func main() {
log.InitWithConfig(log.Config{Name: "console"})
r, err := registry.GetRegistry()
if err != nil {
log.Errorf("Error: %s\n", err)
return
}
cmd := command.NewCommand(r)
if err := cmd.Run(os.Args); err != nil {
log.Errorf("Error: %s\n", err)
}
}
// Proxy the request to the given endpoint, execute observers and middlewares chains
func (l *HttpLocation) proxyToEndpoint(tr *http.Transport, o *Options, endpoint endpoint.Endpoint, req request.Request) (*http.Response, error) {
a := &request.BaseAttempt{Endpoint: endpoint}
l.observerChain.ObserveRequest(req)
defer l.observerChain.ObserveResponse(req, a)
defer req.AddAttempt(a)
it := l.middlewareChain.GetIter()
defer l.unwindIter(it, req, a)
for v := it.Next(); v != nil; v = it.Next() {
a.Response, a.Error = v.ProcessRequest(req)
if a.Response != nil || a.Error != nil {
// Move the iterator forward to count it again once we unwind the chain
it.Next()
log.Errorf("Midleware intercepted request with response=%s, error=%s", a.Response.Status, a.Error)
return a.Response, a.Error
}
}
// Forward the request and mirror the response
start := o.TimeProvider.UtcNow()
a.Response, a.Error = tr.RoundTrip(req.GetHttpRequest())
a.Duration = o.TimeProvider.UtcNow().Sub(start)
return a.Response, a.Error
}
// Subscribe watches etcd changes and generates structured events telling vulcand to add or delete frontends, hosts etc.
// It is a blocking function.
func (n *ng) Subscribe(changes chan interface{}, cancelC chan bool) error {
// This index helps us to get changes in sequence, as they were performed by clients.
waitIndex := uint64(0)
for {
response, err := n.client.Watch(n.etcdKey, waitIndex, true, nil, cancelC)
if err != nil {
switch err {
case etcd.ErrWatchStoppedByUser:
log.Infof("Stop watching: graceful shutdown")
return nil
default:
log.Errorf("unexpected error: %s, stop watching", err)
return err
}
}
waitIndex = response.EtcdIndex + 1
log.Infof("%s", responseToString(response))
change, err := n.parseChange(response)
if err != nil {
log.Warningf("Ignore '%s', error: %s", responseToString(response), err)
continue
}
if change != nil {
log.Infof("%v", change)
select {
case changes <- change:
case <-cancelC:
return nil
}
}
}
}
// Subscribe watches etcd changes and generates structured events telling vulcand to add or delete frontends, hosts etc.
// It is a blocking function.
func (n *ng) Subscribe(changes chan interface{}, cancelC chan bool) error {
w := n.kapi.Watcher(n.etcdKey, &etcd.WatcherOptions{AfterIndex: 0, Recursive: true})
for {
response, err := w.Next(n.context)
if err != nil {
switch err {
case context.Canceled:
log.Infof("Stop watching: graceful shutdown")
return nil
default:
log.Errorf("unexpected error: %s, stop watching", err)
return err
}
}
log.Infof("%s", responseToString(response))
change, err := n.parseChange(response)
if err != nil {
log.Warningf("Ignore '%s', error: %s", responseToString(response), err)
continue
}
if change != nil {
log.Infof("%v", change)
select {
case changes <- change:
case <-cancelC:
return nil
}
}
}
}
// Round trips the request to the selected location and writes back the response
func (p *Proxy) proxyRequest(w http.ResponseWriter, r *http.Request) error {
// Create a unique request with sequential ids that will be passed to all interfaces.
req := request.NewBaseRequest(r, atomic.AddInt64(&p.lastRequestId, 1), nil)
location, err := p.router.Route(req)
if err != nil {
return err
}
// Router could not find a matching location, we can do nothing else.
if location == nil {
log.Errorf("%s failed to route", req)
return errors.FromStatus(http.StatusBadGateway)
}
response, err := location.RoundTrip(req)
if response != nil {
netutils.CopyHeaders(w.Header(), response.Header)
w.WriteHeader(response.StatusCode)
io.Copy(w, response.Body)
response.Body.Close()
return nil
} else {
return err
}
}
func initCacheDir() {
if useFileCache {
if err := os.MkdirAll(tmpDir, os.FileMode(0775)); err != nil {
useFileCache = false
log.Errorf("Couldn't create tmp dir %s: %s", tmpDir, err)
} else {
if err := ioutil.WriteFile(fmt.Sprintf("%s/lock", tmpDir), []byte(version), 0664); err != nil {
useFileCache = false
log.Errorf("Couldn't write to tmp dir %s: %s", tmpDir, err)
}
}
if useFileCache {
log.Infof("Caching via filesystem enabled")
log.Infof("Using %v as cache path", tmpDir)
}
}
}
// registerLocationForScope registers a location with a specified scope.
func (app *App) registerLocationForScope(methods []string, path string, scope Scope, middlewares []middleware.Middleware) {
host, err := app.apiHostForScope(scope)
if err != nil {
log.Errorf("Failed to register a location: %v", err)
return
}
app.registerLocationForHost(methods, path, host, middlewares)
}
// RegisterHandler registers the frontends and middlewares with Vulcand.
func (s *LBRegistry) RegisterHandler(registration *HandlerRegistration) error {
log.Infof("Registering handler: %v", registration)
location := vulcan.NewLocation(registration.Host, registration.Methods, registration.Path, registration.Name, registration.Middlewares)
err := s.client.RegisterFrontend(location)
if err != nil {
log.Errorf("Failed to register frontend for location: %v, %s", location, err)
return err
}
err = s.client.RegisterMiddleware(location)
if err != nil {
log.Errorf("Failed to register middleware for location: %v, %s", location, err)
return err
}
return nil
}
func (n *ng) newHttpTransport() etcd.CancelableTransport {
var cc *tls.Config = nil
if n.options.EtcdCertFile != "" && n.options.EtcdKeyFile != "" {
var rpool *x509.CertPool = nil
if n.options.EtcdCaFile != "" {
if pemBytes, err := ioutil.ReadFile(n.options.EtcdCaFile); err == nil {
rpool = x509.NewCertPool()
rpool.AppendCertsFromPEM(pemBytes)
} else {
log.Errorf("Error reading Etcd Cert CA File: %v", err)
}
}
if tlsCert, err := tls.LoadX509KeyPair(n.options.EtcdCertFile, n.options.EtcdKeyFile); err == nil {
cc = &tls.Config{
RootCAs: rpool,
Certificates: []tls.Certificate{tlsCert},
InsecureSkipVerify: true,
}
} else {
log.Errorf("Error loading KeyPair for TLS client: %v", err)
}
}
//Copied from etcd.DefaultTransport declaration
//Wasn't sure how to make a clean reliable deep-copy, and instead
//creating a new object was the safest and most reliable assurance
//that we aren't overwriting some global struct potentially
//shared by other etcd users.
tr := &http.Transport{
Proxy: http.ProxyFromEnvironment,
Dial: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
}).Dial,
TLSHandshakeTimeout: 10 * time.Second,
TLSClientConfig: cc,
}
return tr
}
func (rw *rewriteHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
oldURL := rawURL(req)
// only continue if the Regexp param matches the URL
if !rw.regexp.MatchString(oldURL) {
rw.next.ServeHTTP(w, req)
return
}
// apply a rewrite regexp to the URL
newURL := rw.regexp.ReplaceAllString(oldURL, rw.replacement)
// replace any variables that may be in there
rewrittenURL := &bytes.Buffer{}
if err := ApplyString(newURL, rewrittenURL, req); err != nil {
rw.errHandler.ServeHTTP(w, req, err)
return
}
// parse the rewritten URL and replace request URL with it
parsedURL, err := url.Parse(rewrittenURL.String())
if err != nil {
rw.errHandler.ServeHTTP(w, req, err)
return
}
if rw.redirect && newURL != oldURL {
(&redirectHandler{u: parsedURL}).ServeHTTP(w, req)
return
}
req.URL = parsedURL
// make sure the request URI corresponds the rewritten URL
req.RequestURI = req.URL.RequestURI()
if !rw.rewriteBody {
rw.next.ServeHTTP(w, req)
return
}
bw := &bufferWriter{header: make(http.Header), buffer: &bytes.Buffer{}}
newBody := &bytes.Buffer{}
rw.next.ServeHTTP(bw, req)
if err := Apply(bw.buffer, newBody, req); err != nil {
log.Errorf("Failed to rewrite response body: %v", err)
return
}
utils.CopyHeaders(w.Header(), bw.Header())
w.Header().Set("Content-Length", strconv.Itoa(newBody.Len()))
w.WriteHeader(bw.code)
io.Copy(w, newBody)
}
func (f *JsonFormatter) Format(err ProxyError) (int, []byte, string) {
encodedError, e := json.Marshal(map[string]interface{}{
"error": string(err.Error()),
})
if e != nil {
log.Errorf("Failed to serialize: %s", e)
encodedError = []byte("{}")
}
return err.GetStatusCode(), encodedError, "application/json"
}
// exec executes side effect
func (c *CircuitBreaker) exec(s SideEffect) {
if s == nil {
return
}
go func() {
if err := s.Exec(); err != nil {
log.Errorf("%v side effect failure: %v", c, err)
}
}()
}
// cacheOptimizedImageWriter Returns a file and a writer for the image resource.
// Be careful to flush the writer and close the file manually, as this function
// doesn't do that.
func fileCacheWriter(fileName string) (f *os.File, w *bufio.Writer) {
dir := path.Dir(fileName)
err := os.MkdirAll(dir, os.FileMode(0775))
if err != nil {
log.Errorf("Error caching image %s: %s", fileName, err)
return
}
f, err = os.Create(fileName)
if err != nil {
log.Errorf("Error caching image %s: %s", fileName, err)
return
}
w = bufio.NewWriter(f)
return
}
func cacheFile(fileName string, data []byte) {
if useFileCache && len(data) > 0 {
go func(fileName string, data []byte) {
fileName = path.Clean(fileName)
dir := path.Dir(fileName)
if err := os.MkdirAll(dir, os.FileMode(0775)); err != nil {
log.Errorf("Error caching image %s: %s", fileName, err)
return
}
if err := ioutil.WriteFile(fileName, data, 0644); err != nil {
log.Errorf("Error caching image %s: %s", fileName, err)
return
}
}(fileName, data)
}
}
// RegisterApp adds a new backend and a single server with Vulcand.
func (s *LBRegistry) RegisterApp(registration *AppRegistration) error {
log.Infof("Registering app: %v", registration)
endpoint, err := vulcan.NewEndpoint(registration.Name, registration.Host, registration.Port)
if err != nil {
return err
}
err = s.client.RegisterBackend(endpoint)
if err != nil {
log.Errorf("Failed to register backend for endpoint: %v, %s", endpoint, err)
return err
}
err = s.client.UpsertServer(endpoint, s.TTL)
if err != nil {
log.Errorf("Failed to register server for endpoint: %v, %s", endpoint, err)
return err
}
return nil
}
func latencyAtQuantile(quantile float64) threshold.RequestToInt {
return func(r request.Request) int {
m := getMetrics(r)
if m == nil {
return 0
}
h, err := m.GetLatencyHistogram()
if err != nil {
log.Errorf("Failed to get latency histogram, for %v error: %v", r, err)
return 0
}
return int(h.LatencyAtQuantile(quantile) / time.Millisecond)
}
}
func (r *Registry) heartbeat() {
defer r.wg.Done()
tick := time.NewTicker(r.cfg.TTL * 3 / 4)
for {
select {
case <-tick.C:
if err := r.registerBackendServer(r.backendSpec, r.cfg.TTL); err != nil {
log.Errorf("Heartbeat failed: err=(%v)", err)
}
case <-r.ctx.Done():
err := r.removeBackendServer(r.backendSpec)
log.Infof("Heartbeat stopped: err=(%v)", err)
return
}
}
}
func (m *RoundTripMetrics) recordStatusCode(a request.Attempt) {
if a.GetResponse() == nil {
return
}
statusCode := a.GetResponse().StatusCode
if c, ok := m.statusCodes[statusCode]; ok {
c.Inc()
return
}
c, err := m.newCounter()
if err != nil {
log.Errorf("failed to create a counter: %v", err)
return
}
c.Inc()
m.statusCodes[statusCode] = c
}
// effectiveRates retrieves rates to be applied to the request.
func (tl *TokenLimiter) effectiveRates(r request.Request) *RateSet {
// If configuration mapper is not specified for this instance, then return
// the default bucket specs.
if tl.configMapper == nil {
return tl.defaultRates
}
rates, err := tl.configMapper(r)
if err != nil {
log.Errorf("Failed to retrieve rates: %v", err)
return tl.defaultRates
}
// If the returned rate set is empty then used the default one.
if len(rates.m) == 0 {
return tl.defaultRates
}
return rates
}
func (r *RoundRobin) adjustWeights() {
if r.options.FailureHandler == nil {
return
}
weights, err := r.options.FailureHandler.AdjustWeights()
if err != nil {
log.Errorf("%s returned error: %s", r.options.FailureHandler, err)
return
}
changed := false
for _, w := range weights {
if w.GetEndpoint().GetEffectiveWeight() != w.GetWeight() {
w.GetEndpoint().setEffectiveWeight(w.GetWeight())
changed = true
}
}
if changed {
r.resetIterator()
}
}
func optimizeAndServeImg(w http.ResponseWriter, r *http.Request, opts optimizer.Options, domain string, imagePath string, body []byte) (err error) {
img, _, err := image.Decode(bytes.NewReader(body))
if err != nil || img == nil {
log.Errorf("Could not decode %s/%s: %s", domain, imagePath, err.Error())
return
}
// If decoding succeeds, cache it.
go cacheDomainFile(domain, imagePath, body)
// If cache enabled, cache the file.
imgHeaders(&w, r)
if useFileCache {
writeAndCacheImg(w, img, opts, getOptimizedImgCachePath(domain, imagePath, opts))
return
}
// If cache disabled, just serve
optimizer.Encode(w, img, opts)
return
}
// Helper that replies with the 500 code and happened error message.
func ReplyInternalError(w http.ResponseWriter, message string) {
log.Errorf("Internal server error: %v", message)
Reply(w, Response{"message": message}, http.StatusInternalServerError)
}
func (m *RoundTripMetrics) recordLatency(a request.Attempt) {
if err := m.histogram.RecordLatencies(a.GetDuration(), 1); err != nil {
log.Errorf("Failed to record latency: %v", err)
}
}
func main() {
// Set up command line flags.
addr := flag.String("listen", ":3000", "IP address/port to listen on")
cacheDir := flag.String("cache-dir", fmt.Sprintf("%s/%s", os.TempDir(), serverName), "Directory for caching static resources")
disableCdn := flag.Bool("disable-cdn", false, "Disable the CDN functionality")
disableProxy := flag.Bool("disable-proxy", false, "Disable the CDN functionality")
cdnPrefix := flag.String("prefix-cdn", "/cdn/", "The prefix for the fetching CDN resources")
proxyPrefix := flag.String("prefix-proxy", "/assets/", "The prefix for handling GET proxy requests")
debug := flag.Bool("debug", true, "Publish stats to /debug/vars")
flag.StringVar(&documentRoot, "docroot", "", "Document root to serve static files. Default is none (disabled)")
flag.BoolVar(&useFileCache, "cache", true, "Enable filesystem caching")
flag.Parse()
tmpDir = *cacheDir
// Make sure cache directory exists.
// and check if we can write to file cache.
initCacheDir()
r := mux.NewRouter()
// CDN proxy subrouter
if !*disableCdn && len(*cdnPrefix) > 0 {
cdnCacheDir := fmt.Sprintf("%s/libraries", tmpDir)
cdnRouter := r.PathPrefix(*cdnPrefix).Subrouter()
log.Infof("Serving cdn files from %s%s", *addr, *cdnPrefix)
if useFileCache {
log.Infof("Caching cdn files in %s", cdnCacheDir)
}
cdn := gocdn.CDN{
Prefix: *cdnPrefix,
CacheDuration: 100,
Cors: true,
CacheDir: cdnCacheDir,
UseFileCache: useFileCache,
}
cdnRouter.HandleFunc(`/{package}/{version}/{path:[^?]+}`, cdn.Handler)
}
if !*disableProxy && len(*proxyPrefix) > 0 {
// General proxy subrouter.
log.Infof("Serving assets via proxy from %s%s ", *addr, *proxyPrefix)
proxyRouter := r.PathPrefix(*proxyPrefix).Subrouter()
proxyRouter.HandleFunc(`/{domain}/{path:.+(jpe?g|png|gif|webp|tiff|bmp)}`, respRemoteImgHandler)
proxyRouter.HandleFunc(`/{domain}/{path:[^?]+}`, proxyHandler)
}
if documentRoot != "" {
log.Infof("Serving static files from %s", documentRoot)
r.HandleFunc(`/{.+(jpe?g|png|gif|webp|tiff|bmp)}`, respLocalImgHandler)
r.PathPrefix("/").Handler(http.FileServer(http.Dir(documentRoot)))
http.Handle("/", r)
}
if *debug {
log.Infof("Publishing stats to /debug/vars")
r.Handle("/debug/vars", http.DefaultServeMux)
}
log.Infof("Ready to listen on %s", *addr)
log.Errorf("Server died: %s", http.ListenAndServe(*addr, handlers.CompressHandler(r)))
}
