From f599a1a2c159f9feb71aefb140555610b6e37e98 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Thu, 21 Jun 2018 10:32:16 -0500
Subject: [PATCH] start the pprof based on an env variable in debug builds,
 otherwise remove the flag/release.go stuff

---
 src/yggdrasil/debug.go   | 14 ++++++++++++++
 src/yggdrasil/release.go | 14 --------------
 yggdrasil.go             |  7 -------
 3 files changed, 14 insertions(+), 21 deletions(-)
 delete mode 100644 src/yggdrasil/release.go

diff --git a/src/yggdrasil/debug.go b/src/yggdrasil/debug.go
index 2cf9040..f95bfa3 100644
--- a/src/yggdrasil/debug.go
+++ b/src/yggdrasil/debug.go
@@ -20,6 +20,20 @@ import "regexp"
 import _ "net/http/pprof"
 import "net/http"
 import "runtime"
+import "os"
+
+// Start the profiler in debug builds, if the required environment variable is set.
+func init() {
+	envVarName := "PPROFLISTEN"
+	hostPort := os.Getenv(envVarName)
+	switch {
+	case hostPort == "":
+		fmt.Printf("DEBUG: %s not set, profiler not started.\n", envVarName)
+	default:
+		fmt.Printf("DEBUG: Starting pprof on %s\n", hostPort)
+		go func() { fmt.Println(http.ListenAndServe(hostPort, nil)) }()
+	}
+}
 
 // Starts the function profiler. This is only supported when built with
 // '-tags build'.
diff --git a/src/yggdrasil/release.go b/src/yggdrasil/release.go
deleted file mode 100644
index 3b13690..0000000
--- a/src/yggdrasil/release.go
+++ /dev/null
@@ -1,14 +0,0 @@
-// +build !debug
-
-package yggdrasil
-
-import (
-	"errors"
-	"log"
-)
-
-// Starts the function profiler. This is only supported when built with
-// '-tags build'.
-func StartProfiler(_ *log.Logger) error {
-	return errors.New("Release builds do not support -pprof, build using '-tags debug'")
-}
diff --git a/yggdrasil.go b/yggdrasil.go
index d29c65b..20b4aa0 100644
--- a/yggdrasil.go
+++ b/yggdrasil.go
@@ -82,7 +82,6 @@ func doGenconf() string {
 // The main function is responsible for configuring and starting Yggdrasil.
 func main() {
 	// Configure the command line parameters.
-	pprof := flag.Bool("pprof", false, "Run pprof, see http://localhost:6060/debug/pprof/")
 	genconf := flag.Bool("genconf", false, "print a new config to stdout")
 	useconf := flag.Bool("useconf", false, "read config from stdin")
 	useconffile := flag.String("useconffile", "", "read config from specified file path")
@@ -203,12 +202,6 @@ func main() {
 	}
 	// Create a new logger that logs output to stdout.
 	logger := log.New(os.Stdout, "", log.Flags())
-	// If the -pprof flag was provided then start the pprof service on port 6060.
-	if *pprof {
-		if err := yggdrasil.StartProfiler(logger); err != nil {
-			logger.Println(err)
-		}
-	}
 	// Setup the Yggdrasil node itself. The node{} type includes a Core, so we
 	// don't need to create this manually.
 	n := node{}