// 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")
}
// 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
}
// RequestToClientIp is a TokenMapper that maps the request to the client IP.
func RequestToClientIp(req request.Request) (string, error) {
vals := strings.SplitN(req.GetHttpRequest().RemoteAddr, ":", 2)
if len(vals[0]) == 0 {
return "", fmt.Errorf("Failed to parse client IP")
}
return vals[0], nil
}
func getMetrics(r request.Request) *metrics.RoundTripMetrics {
m, ok := r.GetUserData(cbreakerMetrics)
if !ok {
return nil
}
return m.(*metrics.RoundTripMetrics)
}
func (r *RoundRobin) NextEndpoint(req request.Request) (endpoint.Endpoint, error) {
r.mutex.Lock()
defer r.mutex.Unlock()
e, err := r.nextEndpoint(req)
if err != nil {
return nil, err
}
lastAttempt := req.GetLastAttempt()
// This is the first try, so just return the selected endpoint
if lastAttempt == nil {
return e, nil
}
// Try to prevent failover to the same endpoint that we've seen before,
// that reduces the probability of the scenario when failover hits same endpoint
// on the next attempt and fails, so users will see a failed request.
var endpoint endpoint.Endpoint
for _ = range r.endpoints {
endpoint, err = r.nextEndpoint(req)
if err != nil {
return nil, err
}
if !hasAttempted(req, endpoint) {
return endpoint, nil
}
}
return endpoint, nil
}
func (tl *TokenLimiter) ProcessRequest(r request.Request) (*http.Response, error) {
tl.mutex.Lock()
defer tl.mutex.Unlock()
token, amount, err := tl.mapper(r)
if err != nil {
return nil, err
}
bucketI, exists := tl.buckets.Get(token)
if !exists {
bucketI, err = NewTokenBucket(tl.rate, tl.options.Burst+1, tl.options.TimeProvider)
if err != nil {
return nil, err
}
// We set ttl as 10 times rate period. E.g. if rate is 100 requests/second per client ip
// the counters for this ip will expire after 10 seconds of inactivity
tl.buckets.Set(token, bucketI, int(tl.rate.Period/time.Second)*10+1)
}
bucket := bucketI.(*TokenBucket)
delay, err := bucket.Consume(amount)
if err != nil {
return nil, err
}
if delay > 0 {
return netutils.NewTextResponse(r.GetHttpRequest(), errors.StatusTooManyRequests, "Too many requests"), nil
}
return nil, nil
}
func (tl *TokenLimiter) ProcessRequest(r request.Request) (*http.Response, error) {
tl.mutex.Lock()
defer tl.mutex.Unlock()
token, amount, err := tl.mapper(r)
if err != nil {
return nil, err
}
effectiveRates := tl.effectiveRates(r)
bucketSetI, exists := tl.bucketSets.Get(token)
var bucketSet *tokenBucketSet
if exists {
bucketSet = bucketSetI.(*tokenBucketSet)
bucketSet.update(effectiveRates)
} else {
bucketSet = newTokenBucketSet(effectiveRates, tl.clock)
// We set ttl as 10 times rate period. E.g. if rate is 100 requests/second per client ip
// the counters for this ip will expire after 10 seconds of inactivity
tl.bucketSets.Set(token, bucketSet, int(bucketSet.maxPeriod/time.Second)*10+1)
}
delay, err := bucketSet.consume(amount)
if err != nil {
return nil, err
}
if delay > 0 {
return netutils.NewTextResponse(r.GetHttpRequest(), errors.StatusTooManyRequests, "Too many requests"), nil
}
return nil, nil
}
func hasAttempted(req request.Request, endpoint endpoint.Endpoint) bool {
for _, a := range req.GetAttempts() {
if a.GetEndpoint().GetId() == endpoint.GetId() {
return true
}
}
return false
}
func (m *methodMatcher) match(req request.Request) location.Location {
for _, c := range m.methods {
if req.GetHttpRequest().Method == c {
return m.matcher.match(req)
}
}
return nil
}
func (e *ExpRouter) Route(req request.Request) (location.Location, error) {
l, err := e.r.Route(req.GetHttpRequest())
if err != nil {
return nil, err
}
if l == nil {
return nil, nil
}
return l.(location.Location), nil
}
// Takes the request and returns the location if the request path matches any of it's paths
// returns nil if none of the requests matches
func (p *trie) match(r request.Request) location.Location {
if p.root == nil {
return nil
}
path := r.GetHttpRequest().URL.Path
if len(path) == 0 {
path = "/"
}
return p.root.match(-1, path, r)
}
func (c *CircuitBreaker) checkCondition(r request.Request) bool {
if !c.timeToCheck() {
return false
}
c.m.Lock()
defer c.m.Unlock()
// Other goroutine could have updated the lastCheck variable before we grabbed mutex
if !c.tm.UtcNow().After(c.lastCheck) {
return false
}
c.lastCheck = c.tm.UtcNow().Add(c.checkPeriod)
// Each requests holds a context attached to it, we use it to attach the metrics to the request
// so condition checker function can use it for analysis on the next line.
r.SetUserData(cbreakerMetrics, c.metrics)
return c.condition(r)
}
func (rw *Rewriter) ProcessRequest(r request.Request) (*http.Response, error) {
req := r.GetHttpRequest()
if clientIP, _, err := net.SplitHostPort(req.RemoteAddr); err == nil {
if rw.TrustForwardHeader {
if prior, ok := req.Header[headers.XForwardedFor]; ok {
clientIP = strings.Join(prior, ", ") + ", " + clientIP
}
}
req.Header.Set(headers.XForwardedFor, clientIP)
}
if xfp := req.Header.Get(headers.XForwardedProto); xfp != "" && rw.TrustForwardHeader {
req.Header.Set(headers.XForwardedProto, xfp)
} else if req.TLS != nil {
req.Header.Set(headers.XForwardedProto, "https")
} else {
req.Header.Set(headers.XForwardedProto, "http")
}
if req.Host != "" {
req.Header.Set(headers.XForwardedHost, req.Host)
}
req.Header.Set(headers.XForwardedServer, rw.Hostname)
// Remove hop-by-hop headers to the backend. Especially important is "Connection" because we want a persistent
// connection, regardless of what the client sent to us.
netutils.RemoveHeaders(headers.HopHeaders, req.Header)
// We need to set ContentLength based on known request size. The incoming request may have been
// set without content length or using chunked TransferEncoding
totalSize, err := r.GetBody().TotalSize()
if err != nil {
return nil, err
}
req.ContentLength = totalSize
// Remove TransferEncoding that could have been previously set
req.TransferEncoding = []string{}
return nil, nil
}
func (cl *ConnectionLimiter) ProcessRequest(r request.Request) (*http.Response, error) {
cl.mutex.Lock()
defer cl.mutex.Unlock()
token, amount, err := cl.mapper(r)
if err != nil {
return nil, err
}
connections := cl.connections[token]
if connections >= cl.maxConnections {
return netutils.NewTextResponse(
r.GetHttpRequest(),
errors.StatusTooManyRequests,
fmt.Sprintf("Connection limit reached. Max is: %d, yours: %d", cl.maxConnections, connections)), nil
}
cl.connections[token] += amount
cl.totalConnections += int64(amount)
return nil, nil
}
func (l *HttpLocation) isRequestOverLimit(req request.Request) bool {
if l.options.Limits.MaxBodyBytes <= 0 {
return false
}
return req.GetHttpRequest().ContentLength > l.options.Limits.MaxBodyBytes
}
// Failover in case if last attempt resulted in error
func IsNetworkError(req request.Request) bool {
attempts := len(req.GetAttempts())
return attempts != 0 && req.GetAttempts()[attempts-1].GetError() != nil
}
func (l *ConstHttpLocation) RoundTrip(r request.Request) (*http.Response, error) {
req := r.GetHttpRequest()
req.URL = netutils.MustParseUrl(l.Url)
return http.DefaultTransport.RoundTrip(req)
}
func (c *CircuitBreaker) shouldRecordMetrics(r request.Request) bool {
_, ok := r.GetUserData(cbreakerRecordMetrics)
return ok
}
func (c *CircuitBreaker) markToRecordMetrics(r request.Request) {
r.SetUserData(cbreakerRecordMetrics, true)
}
// RequestToHost maps request to the host value
func RequestToHost(req request.Request) (string, error) {
return req.GetHttpRequest().Host, nil
}
// Maps request to it's size in bytes
func RequestToBytes(req request.Request) (int64, error) {
return req.GetBody().TotalSize()
}
// Maps request to its path
func mapRequestToPath(req request.Request) string {
return req.GetHttpRequest().URL.Path
}
func (re *Response) getHTTPResponse(r request.Request) *http.Response {
return netutils.NewHttpResponse(r.GetHttpRequest(), re.StatusCode, re.Body, re.ContentType)
}