adding pprof middleware

Author: Arun Gopalpuri

README.md

@@ -14,3 +14,4 @@ Name | Description | Author
 session | Session middleware backed by [gorilla/sessions](https://github.com/gorilla/sessions) | [vishr](https://github.com/vishr)
 jaegertracing | Jaeger tracer middleware | [carlosedp](https://github.com/carlosedp)
 prometheus | Prometheus metrics | [carlosedp](https://github.com/carlosedp)
+pprof      | pprof middlware | [arun0009](https://github.com/arun0009)

pprof/README.md

@@ -0,0 +1,38 @@
+Usage
+
+```code go
+package main
+
+import (
+	"net/http"
+
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo-contrib/pprof"
+
+)
+
+func main() {
+	e := echo.New()
+	pprof.Register(e)
+    ......
+	e.Logger.Fatal(e.Start(":1323"))
+}
+```
+
+- Then use the pprof tool to look at the heap profile:
+
+    `go tool pprof http://localhost:1323/debug/pprof/heap`
+
+-  Or to look at a 30-second CPU profile:
+    
+    `go tool pprof http://localhost:1323/debug/pprof/profile?seconds=30`
+
+- Or to look at the goroutine blocking profile, after calling runtime.SetBlockProfileRate in your program:
+    
+    `go tool pprof http://localhost:1323/debug/pprof/block`
+
+- Or to look at the holders of contended mutexes, after calling runtime.SetMutexProfileFraction in your program:
+    
+    `go tool pprof http://localhost:1323/debug/pprof/mutex`
+
+

pprof/pprof.go

@@ -0,0 +1,48 @@
+package pprof
+
+import (
+	"net/http"
+	"net/http/pprof"
+
+	"github.com/labstack/echo/v4"
+)
+
+const (
+	// DefaultPrefix url prefix of pprof
+	DefaultPrefix = "/debug/pprof"
+)
+
+func getPrefix(prefixOptions ...string) string {
+	if len(prefixOptions) > 0 {
+		return prefixOptions[0]
+	}
+	return DefaultPrefix
+}
+
+// Register middleware for net/http/pprof
+func Register(e *echo.Echo, prefixOptions ...string) {
+	prefix := getPrefix(prefixOptions...)
+
+	prefixRouter := e.Group(prefix)
+	{
+		prefixRouter.GET("/", handler(pprof.Index))
+		prefixRouter.GET("/allocs", handler(pprof.Handler("allocs").ServeHTTP))
+		prefixRouter.GET("/block", handler(pprof.Handler("block").ServeHTTP))
+		prefixRouter.GET("/cmdline", handler(pprof.Cmdline))
+		prefixRouter.GET("/goroutine", handler(pprof.Handler("goroutine").ServeHTTP))
+		prefixRouter.GET("/heap", handler(pprof.Handler("heap").ServeHTTP))
+		prefixRouter.GET("/mutex", handler(pprof.Handler("mutex").ServeHTTP))
+		prefixRouter.GET("/profile", handler(pprof.Profile))
+		prefixRouter.POST("/symbol", handler(pprof.Symbol))
+		prefixRouter.GET("/symbol", handler(pprof.Symbol))
+		prefixRouter.GET("/threadcreate", handler(pprof.Handler("threadcreate").ServeHTTP))
+		prefixRouter.GET("/trace", handler(pprof.Trace))
+	}
+}
+
+func handler(h http.HandlerFunc) echo.HandlerFunc {
+	return func(c echo.Context) error {
+		h.ServeHTTP(c.Response().Writer, c.Request())
+		return nil
+	}
+}

pprof/pprof_test.go

@@ -0,0 +1,69 @@
+package pprof
+
+import (
+	"github.com/stretchr/testify/assert"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/labstack/echo/v4"
+)
+
+func TestPProfRegisterDefaualtPrefix(t *testing.T) {
+	var pprofPaths = []struct {
+		path string
+	}{
+		{"/"},
+		{"/allocs"},
+		{"/block"},
+		{"/cmdline"},
+		{"/goroutine"},
+		{"/heap"},
+		{"/mutex"},
+		{"/profile?seconds=1"},
+		{"/symbol"},
+		{"/symbol"},
+		{"/threadcreate"},
+		{"/trace"},
+	}
+	for _, tt := range pprofPaths {
+		t.Run(tt.path, func(t *testing.T) {
+			e := echo.New()
+			Register(e)
+			req, _ := http.NewRequest(http.MethodGet, DefaultPrefix+tt.path, nil)
+			rec := httptest.NewRecorder()
+			e.ServeHTTP(rec, req)
+			assert.Equal(t, rec.Code, http.StatusOK)
+		})
+	}
+}
+
+func TestPProfRegisterCustomPrefix(t *testing.T) {
+	var pprofPaths = []struct {
+		path string
+	}{
+		{"/"},
+		{"/allocs"},
+		{"/block"},
+		{"/cmdline"},
+		{"/goroutine"},
+		{"/heap"},
+		{"/mutex"},
+		{"/profile?seconds=1"},
+		{"/symbol"},
+		{"/symbol"},
+		{"/threadcreate"},
+		{"/trace"},
+	}
+	for _, tt := range pprofPaths {
+		t.Run(tt.path, func(t *testing.T) {
+			e := echo.New()
+			pprofPrefix := "/myapp/pprof"
+			Register(e, pprofPrefix)
+			req, _ := http.NewRequest(http.MethodGet, pprofPrefix+tt.path, nil)
+			rec := httptest.NewRecorder()
+			e.ServeHTTP(rec, req)
+			assert.Equal(t, rec.Code, http.StatusOK)
+		})
+	}
+}