mirror of
https://github.com/openfaas/faas.git
synced 2025-06-15 19:56:47 +00:00
131 lines
3.2 KiB
Go
131 lines
3.2 KiB
Go
package handlers
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import (
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"context"
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"io"
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"log"
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"net/http"
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"strconv"
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"strings"
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"time"
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"github.com/openfaas/faas/gateway/metrics"
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"github.com/openfaas/faas/gateway/types"
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"github.com/prometheus/client_golang/prometheus"
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)
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type HTTPNotifier interface {
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Notify(method string, URL string, statusCode int, duration time.Duration)
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}
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// MakeForwardingProxyHandler create a handler which forwards HTTP requests
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func MakeForwardingProxyHandler(proxy *types.HTTPClientReverseProxy, notifiers []HTTPNotifier) http.HandlerFunc {
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baseURL := proxy.BaseURL.String()
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if strings.HasSuffix(baseURL, "/") {
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baseURL = baseURL[0 : len(baseURL)-1]
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}
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return func(w http.ResponseWriter, r *http.Request) {
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requestURL := r.URL.String()
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start := time.Now()
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statusCode, err := forwardRequest(w, r, proxy.Client, baseURL, requestURL, proxy.Timeout)
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seconds := time.Since(start)
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if err != nil {
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log.Printf("error with upstream request to: %s, %s\n", requestURL, err.Error())
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}
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for _, notifier := range notifiers {
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notifier.Notify(r.Method, requestURL, statusCode, seconds)
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}
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}
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}
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func forwardRequest(w http.ResponseWriter, r *http.Request, proxyClient *http.Client, baseURL string, requestURL string, timeout time.Duration) (int, error) {
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upstreamReq, _ := http.NewRequest(r.Method, baseURL+requestURL, nil)
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copyHeaders(upstreamReq.Header, &r.Header)
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upstreamReq.Header["X-Forwarded-For"] = []string{r.RemoteAddr}
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if r.Body != nil {
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defer r.Body.Close()
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upstreamReq.Body = r.Body
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}
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ctx, cancel := context.WithTimeout(context.Background(), timeout)
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defer cancel()
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res, resErr := proxyClient.Do(upstreamReq.WithContext(ctx))
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if resErr != nil {
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badStatus := http.StatusBadGateway
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w.WriteHeader(badStatus)
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return badStatus, resErr
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}
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if res.Body != nil {
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defer res.Body.Close()
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}
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copyHeaders(w.Header(), &res.Header)
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// Write status code
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w.WriteHeader(res.StatusCode)
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if res.Body != nil {
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// Copy the body over
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io.CopyBuffer(w, res.Body, nil)
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}
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return res.StatusCode, nil
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}
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func copyHeaders(destination http.Header, source *http.Header) {
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for k, v := range *source {
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vClone := make([]string, len(v))
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copy(vClone, v)
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(destination)[k] = vClone
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}
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}
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type PrometheusFunctionNotifier struct {
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Metrics *metrics.MetricOptions
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}
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func (p PrometheusFunctionNotifier) Notify(method string, URL string, statusCode int, duration time.Duration) {
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seconds := duration.Seconds()
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serviceName := getServiceName(URL)
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p.Metrics.GatewayFunctionsHistogram.
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WithLabelValues(serviceName).
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Observe(seconds)
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code := strconv.Itoa(statusCode)
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p.Metrics.GatewayFunctionInvocation.
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With(prometheus.Labels{"function_name": serviceName, "code": code}).
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Inc()
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}
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func getServiceName(urlValue string) string {
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var serviceName string
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forward := "/function/"
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if startsWith(urlValue, forward) {
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serviceName = urlValue[len(forward):]
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}
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return serviceName
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}
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func startsWith(value, token string) bool {
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return len(value) > len(token) && strings.Index(value, token) == 0
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}
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type LoggingNotifier struct {
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}
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func (LoggingNotifier) Notify(method string, URL string, statusCode int, duration time.Duration) {
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log.Printf("Forwarded [%s] to %s - [%d] - %f seconds", method, URL, statusCode, duration.Seconds())
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}
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