Start logging metrics

gateway/server.go

@@ -5,6 +5,9 @@ import (
 	"log"
 	"net/http"
 	"net/http/httputil"
+	"strconv"
+	"strings"
+	"time"
 
 	"fmt"
 
@@ -13,6 +16,7 @@ import (
 	"github.com/alexellis/faas/gateway/metrics"
 	"github.com/alexellis/faas/gateway/types"
 	"github.com/docker/docker/client"
+	"github.com/prometheus/client_golang/prometheus"
 
 	"github.com/gorilla/mux"
 )
@@ -63,12 +67,12 @@ func main() {
 
 		reverseProxy := httputil.NewSingleHostReverseProxy(config.FunctionsProviderURL)
 
-		faasHandlers.Proxy = handler(reverseProxy)
-		faasHandlers.RoutelessProxy = handler(reverseProxy)
-		faasHandlers.Alert = handler(reverseProxy)
-		faasHandlers.ListFunctions = handler(reverseProxy)
-		faasHandlers.DeployFunction = handler(reverseProxy)
-		faasHandlers.DeleteFunction = handler(reverseProxy)
+		faasHandlers.Proxy = makeHandler(reverseProxy, &metricsOptions)
+		faasHandlers.RoutelessProxy = makeHandler(reverseProxy, &metricsOptions)
+		faasHandlers.Alert = makeHandler(reverseProxy, &metricsOptions)
+		faasHandlers.ListFunctions = makeHandler(reverseProxy, &metricsOptions)
+		faasHandlers.DeployFunction = makeHandler(reverseProxy, &metricsOptions)
+		faasHandlers.DeleteFunction = makeHandler(reverseProxy, &metricsOptions)
 
 	} else {
 		faasHandlers.Proxy = internalHandlers.MakeProxy(metricsOptions, true, dockerClient, &logger)
@@ -116,9 +120,68 @@ func main() {
 	log.Fatal(s.ListenAndServe())
 }
 
-func handler(p *httputil.ReverseProxy) func(http.ResponseWriter, *http.Request) {
+// WriteAdapter adapts a ResponseWriter
+type WriteAdapter struct {
+	Writer     http.ResponseWriter
+	HttpResult *HttpResult
+}
+type HttpResult struct {
+	HeaderCode int
+}
+
+//NewWriteAdapter create a new NewWriteAdapter
+func NewWriteAdapter(w http.ResponseWriter) WriteAdapter {
+	return WriteAdapter{Writer: w, HttpResult: &HttpResult{}}
+}
+
+//Header adapts Header
+func (w WriteAdapter) Header() http.Header {
+	return w.Writer.Header()
+}
+
+// Write adapts Write
+func (w WriteAdapter) Write(data []byte) (int, error) {
+	return w.Writer.Write(data)
+}
+
+// WriteHeader adapts WriteHeader
+func (w WriteAdapter) WriteHeader(i int) {
+	w.Writer.WriteHeader(i)
+	w.HttpResult.HeaderCode = i
+	fmt.Println("GetHeaderCode before", w.HttpResult.HeaderCode)
+}
+
+// GetHeaderCode result from WriteHeader
+func (w *WriteAdapter) GetHeaderCode() int {
+	return w.HttpResult.HeaderCode
+}
+
+func makeHandler(proxy *httputil.ReverseProxy, metrics *metrics.MetricOptions) http.HandlerFunc {
+	// return func(http.ResponseWriter, *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
+		uri := r.URL.String()
+
 		log.Printf("Forwarding [%s] to %s", r.Method, r.URL.String())
-		p.ServeHTTP(w, r)
+		start := time.Now()
+
+		writeAdapter := NewWriteAdapter(w)
+		proxy.ServeHTTP(writeAdapter, r)
+
+		seconds := time.Since(start).Seconds()
+		fmt.Printf("[%d] took %f seconds\n", writeAdapter.GetHeaderCode(), seconds)
+
+		forward := "/function/"
+		// fmt.Println(uri)
+		if len(uri) > len(forward) && strings.Index(uri, forward) == 0 {
+			fmt.Println("function=", uri[len(forward):])
+			service := uri[len(forward):]
+			metrics.GatewayFunctionsHistogram.WithLabelValues(service).Observe(seconds)
+			code := writeAdapter.GetHeaderCode()
+			metrics.GatewayFunctionInvocation.With(prometheus.Labels{"function_name": service, "code": strconv.Itoa(code)}).Inc()
+
+		}
+
+		// metricsOptions.
 	}
+	// }
 }