update provider to v0.19

Signed-off-by: Nitishkumar Singh <nitishkumarsingh71@gmail.com>

updated go version

Signed-off-by: Nitishkumar Singh <nitishkumarsingh71@gmail.com>

vendor/github.com/openfaas/faas-provider/httputil/write_interceptor.go

@@ -0,0 +1,54 @@
+package httputil
+
+import (
+	"bufio"
+	"net"
+	"net/http"
+)
+
+func NewHttpWriteInterceptor(w http.ResponseWriter) *HttpWriteInterceptor {
+	return &HttpWriteInterceptor{w, 0}
+}
+
+type HttpWriteInterceptor struct {
+	http.ResponseWriter
+	StatusCode int
+}
+
+func (c *HttpWriteInterceptor) Status() int {
+	if c.StatusCode == 0 {
+		return http.StatusOK
+	}
+	return c.StatusCode
+}
+
+func (c *HttpWriteInterceptor) Header() http.Header {
+	return c.ResponseWriter.Header()
+}
+
+func (c *HttpWriteInterceptor) Write(data []byte) (int, error) {
+	return c.ResponseWriter.Write(data)
+}
+
+func (c *HttpWriteInterceptor) WriteHeader(code int) {
+	c.StatusCode = code
+	c.ResponseWriter.WriteHeader(code)
+}
+
+func (c *HttpWriteInterceptor) Flush() {
+	fl := c.ResponseWriter.(http.Flusher)
+	fl.Flush()
+}
+
+func (c *HttpWriteInterceptor) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	hj := c.ResponseWriter.(http.Hijacker)
+	return hj.Hijack()
+}
+
+func (c *HttpWriteInterceptor) CloseNotify() <-chan bool {
+	notifier, ok := c.ResponseWriter.(http.CloseNotifier)
+	if ok == false {
+		return nil
+	}
+	return notifier.CloseNotify()
+}

vendor/github.com/openfaas/faas-provider/metrics.go

@@ -0,0 +1,72 @@
+package bootstrap
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/openfaas/faas-provider/httputil"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+// httpMetrics is for recording R.E.D. metrics for system endpoint calls
+// for HTTP status code, method, duration and path.
+type httpMetrics struct {
+	// RequestsTotal is a Prometheus counter vector partitioned by method and status.
+	RequestsTotal *prometheus.CounterVec
+
+	// RequestDurationHistogram is a Prometheus summary vector partitioned by method and status.
+	RequestDurationHistogram *prometheus.HistogramVec
+}
+
+// newHttpMetrics initialises a new httpMetrics struct for
+// recording R.E.D. metrics for system endpoint calls
+func newHttpMetrics() *httpMetrics {
+	return &httpMetrics{
+		RequestsTotal: promauto.NewCounterVec(prometheus.CounterOpts{
+			Subsystem: "provider",
+			Name:      "http_requests_total",
+			Help:      "Total number of HTTP requests.",
+		}, []string{"code", "method", "path"}),
+		RequestDurationHistogram: promauto.NewHistogramVec(prometheus.HistogramOpts{
+			Subsystem: "provider",
+			Name:      "http_request_duration_seconds",
+			Help:      "Seconds spent serving HTTP requests.",
+			Buckets:   prometheus.DefBuckets,
+		}, []string{"code", "method", "path"}),
+	}
+}
+
+func (hm *httpMetrics) InstrumentHandler(next http.Handler, pathOverride string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+
+		start := time.Now()
+		ww := httputil.NewHttpWriteInterceptor(w)
+		next.ServeHTTP(ww, r)
+		duration := time.Since(start)
+
+		path := r.URL.Path
+		if len(pathOverride) > 0 {
+			path = pathOverride
+		}
+
+		defer func() {
+			hm.RequestsTotal.With(
+				prometheus.Labels{"code": strconv.Itoa(ww.StatusCode),
+					"method": r.Method,
+					"path":   path,
+				}).
+				Inc()
+		}()
+
+		defer func() {
+			hm.RequestDurationHistogram.With(
+				prometheus.Labels{"code": strconv.Itoa(ww.StatusCode),
+					"method": r.Method,
+					"path":   path,
+				}).
+				Observe(duration.Seconds())
+		}()
+	}
+}

vendor/github.com/openfaas/faas-provider/serve.go

@@ -11,6 +11,8 @@ import (
 	"github.com/gorilla/mux"
 	"github.com/openfaas/faas-provider/auth"
 	"github.com/openfaas/faas-provider/types"
+
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 // NameExpression for a function / service
@@ -52,30 +54,42 @@ func Serve(handlers *types.FaaSHandlers, config *types.FaaSConfig) {
 		handlers.LogHandler = auth.DecorateWithBasicAuth(handlers.LogHandler, credentials)
 	}
 
+	hm := newHttpMetrics()
+
 	// System (auth) endpoints
-	r.HandleFunc("/system/functions", handlers.FunctionReader).Methods(http.MethodGet)
-	r.HandleFunc("/system/functions", handlers.DeployHandler).Methods(http.MethodPost)
-	r.HandleFunc("/system/functions", handlers.DeleteHandler).Methods(http.MethodDelete)
-	r.HandleFunc("/system/functions", handlers.UpdateHandler).Methods(http.MethodPut)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.FunctionReader, "")).Methods(http.MethodGet)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.DeployHandler, "")).Methods(http.MethodPost)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.DeleteHandler, "")).Methods(http.MethodDelete)
+	r.HandleFunc("/system/functions", hm.InstrumentHandler(handlers.UpdateHandler, "")).Methods(http.MethodPut)
 
-	r.HandleFunc("/system/function/{name:["+NameExpression+"]+}", handlers.ReplicaReader).Methods(http.MethodGet)
-	r.HandleFunc("/system/scale-function/{name:["+NameExpression+"]+}", handlers.ReplicaUpdater).Methods(http.MethodPost)
-	r.HandleFunc("/system/info", handlers.InfoHandler).Methods(http.MethodGet)
+	r.HandleFunc("/system/function/{name:["+NameExpression+"]+}",
+		hm.InstrumentHandler(handlers.ReplicaReader, "/system/function")).Methods(http.MethodGet)
+	r.HandleFunc("/system/scale-function/{name:["+NameExpression+"]+}",
 
-	r.HandleFunc("/system/secrets", handlers.SecretHandler).Methods(http.MethodGet, http.MethodPut, http.MethodPost, http.MethodDelete)
-	r.HandleFunc("/system/logs", handlers.LogHandler).Methods(http.MethodGet)
+		hm.InstrumentHandler(handlers.ReplicaUpdater, "/system/scale-function")).Methods(http.MethodPost)
+	r.HandleFunc("/system/info",
+		hm.InstrumentHandler(handlers.InfoHandler, "")).Methods(http.MethodGet)
 
-	r.HandleFunc("/system/namespaces", handlers.ListNamespaceHandler).Methods(http.MethodGet)
+	r.HandleFunc("/system/secrets",
+		hm.InstrumentHandler(handlers.SecretHandler, "")).Methods(http.MethodGet, http.MethodPut, http.MethodPost, http.MethodDelete)
+	r.HandleFunc("/system/logs",
+		hm.InstrumentHandler(handlers.LogHandler, "")).Methods(http.MethodGet)
+
+	r.HandleFunc("/system/namespaces", hm.InstrumentHandler(handlers.ListNamespaceHandler, "")).Methods(http.MethodGet)
+
+	proxyHandler := handlers.FunctionProxy
 
 	// Open endpoints
-	r.HandleFunc("/function/{name:["+NameExpression+"]+}", handlers.FunctionProxy)
-	r.HandleFunc("/function/{name:["+NameExpression+"]+}/", handlers.FunctionProxy)
-	r.HandleFunc("/function/{name:["+NameExpression+"]+}/{params:.*}", handlers.FunctionProxy)
+	r.HandleFunc("/function/{name:["+NameExpression+"]+}", proxyHandler)
+	r.HandleFunc("/function/{name:["+NameExpression+"]+}/", proxyHandler)
+	r.HandleFunc("/function/{name:["+NameExpression+"]+}/{params:.*}", proxyHandler)
 
 	if handlers.HealthHandler != nil {
 		r.HandleFunc("/healthz", handlers.HealthHandler).Methods(http.MethodGet)
 	}
 
+	r.HandleFunc("/metrics", promhttp.Handler().ServeHTTP)
+
 	readTimeout := config.ReadTimeout
 	writeTimeout := config.WriteTimeout