From 640a0ef956e2b27f64122075d89a9dfbcf8ce6c0 Mon Sep 17 00:00:00 2001
From: Craig Peterson <cpeterson@stackoverflow.com>
Date: Fri, 18 Mar 2016 10:39:29 -0600
Subject: [PATCH] Adding pprof middleware for debugging purposes

---
 caddy/directives.go       |  1 +
 caddy/setup/pprof.go      | 26 ++++++++++++++++++++++++++
 caddy/setup/pprof_test.go | 28 ++++++++++++++++++++++++++++
 middleware/pprof/pprof.go | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 89 insertions(+)
 create mode 100644 caddy/setup/pprof.go
 create mode 100644 caddy/setup/pprof_test.go
 create mode 100644 middleware/pprof/pprof.go

diff --git a/caddy/directives.go b/caddy/directives.go
index fd5245085..f9da35d2f 100644
--- a/caddy/directives.go
+++ b/caddy/directives.go
@@ -61,6 +61,7 @@ var directiveOrder = []directive{
 	{"mime", setup.Mime},
 	{"basicauth", setup.BasicAuth},
 	{"internal", setup.Internal},
+	{"pprof", setup.PProf},
 	{"proxy", setup.Proxy},
 	{"fastcgi", setup.FastCGI},
 	{"websocket", setup.WebSocket},
diff --git a/caddy/setup/pprof.go b/caddy/setup/pprof.go
new file mode 100644
index 000000000..269439455
--- /dev/null
+++ b/caddy/setup/pprof.go
@@ -0,0 +1,26 @@
+package setup
+
+import (
+	"github.com/mholt/caddy/middleware"
+	"github.com/mholt/caddy/middleware/pprof"
+)
+
+//PProf returns a new instance of a pprof handler. It accepts no arguments or options.
+func PProf(c *Controller) (middleware.Middleware, error) {
+	found := false
+	for c.Next() {
+		if found {
+			return nil, c.Err("pprof can only be specified once")
+		}
+		if len(c.RemainingArgs()) != 0 {
+			return nil, c.ArgErr()
+		}
+		if c.NextBlock() {
+			return nil, c.ArgErr()
+		}
+		found = true
+	}
+	return func(next middleware.Handler) middleware.Handler {
+		return pprof.New(next)
+	}, nil
+}
diff --git a/caddy/setup/pprof_test.go b/caddy/setup/pprof_test.go
new file mode 100644
index 000000000..ac9375af7
--- /dev/null
+++ b/caddy/setup/pprof_test.go
@@ -0,0 +1,28 @@
+package setup
+
+import "testing"
+
+func TestPProf(t *testing.T) {
+	tests := []struct {
+		input     string
+		shouldErr bool
+	}{
+		{`pprof`, false},
+		{`pprof {}`, true},
+		{`pprof /foo`, true},
+		{`pprof {
+            a b
+        }`, true},
+		{`pprof
+          pprof`, true},
+	}
+	for i, test := range tests {
+		c := NewTestController(test.input)
+		_, err := PProf(c)
+		if test.shouldErr && err == nil {
+			t.Errorf("Test %v: Expected error but found nil", i)
+		} else if !test.shouldErr && err != nil {
+			t.Errorf("Test %v: Expected no error but found error: %v", i, err)
+		}
+	}
+}
diff --git a/middleware/pprof/pprof.go b/middleware/pprof/pprof.go
new file mode 100644
index 000000000..d78d34bab
--- /dev/null
+++ b/middleware/pprof/pprof.go
@@ -0,0 +1,34 @@
+package pprof
+
+import (
+	"net/http"
+	pp "net/http/pprof"
+
+	"github.com/mholt/caddy/middleware"
+)
+
+//Handler is a simple struct whose ServeHTTP will delegate relevant pprof endpoints to net/http/pprof
+type handler struct {
+	mux *http.ServeMux
+}
+
+//New creates a new pprof middleware
+func New(next middleware.Handler) middleware.Handler {
+	//pretty much copying what pprof does on init: https://golang.org/src/net/http/pprof/pprof.go#L67
+	mux := http.NewServeMux()
+	mux.HandleFunc("/debug/pprof/", pp.Index)
+	mux.HandleFunc("/debug/pprof/cmdline", pp.Cmdline)
+	mux.HandleFunc("/debug/pprof/profile", pp.Profile)
+	mux.HandleFunc("/debug/pprof/symbol", pp.Symbol)
+	mux.HandleFunc("/debug/pprof/trace", pp.Trace)
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		next.ServeHTTP(w, r)
+	})
+	return &handler{mux}
+}
+
+func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
+	rec := middleware.NewResponseRecorder(w)
+	h.mux.ServeHTTP(rec, r)
+	return rec.Status(), nil
+}