From 211ed6af991534a7a95437c9e6d0178927c008eb Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Tue, 13 Mar 2018 14:46:39 -0400
Subject: [PATCH 1/2] add an option to expose a pprof http endpoint

---
 irc/config.go |  3 ++-
 irc/server.go | 31 +++++++++++++++++++++++++++++++
 oragono.yaml  |  6 ++++++
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/irc/config.go b/irc/config.go
index a5600663..f0561e00 100644
--- a/irc/config.go
+++ b/irc/config.go
@@ -237,7 +237,8 @@ type Config struct {
 	Logging []logger.LoggingConfig
 
 	Debug struct {
-		RecoverFromErrors *bool `yaml:"recover-from-errors"`
+		RecoverFromErrors *bool   `yaml:"recover-from-errors"`
+		PprofListener     *string `yaml:"pprof-listener"`
 		StackImpact       StackImpactConfig
 	}
 
diff --git a/irc/server.go b/irc/server.go
index 8bd8bda0..9e6e0a22 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -13,6 +13,8 @@ import (
 	"log"
 	"math/rand"
 	"net"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"os/signal"
 	"strconv"
@@ -120,6 +122,7 @@ type Server struct {
 	recoverFromErrors          bool
 	rehashMutex                sync.Mutex // tier 4
 	rehashSignal               chan os.Signal
+	pprofServer                *http.Server
 	proxyAllowedFrom           []string
 	signals                    chan os.Signal
 	snomasks                   *SnoManager
@@ -968,6 +971,8 @@ func (server *Server) applyConfig(config *Config, initial bool) error {
 		}
 	}
 
+	server.setupPprofListener(config)
+
 	// we are now open for business
 	server.setupListeners(config)
 
@@ -987,6 +992,32 @@ func (server *Server) applyConfig(config *Config, initial bool) error {
 	return nil
 }
 
+func (server *Server) setupPprofListener(config *Config) {
+	pprofListener := ""
+	if config.Debug.PprofListener != nil {
+		pprofListener = *config.Debug.PprofListener
+	}
+	if server.pprofServer != nil {
+		if pprofListener == "" || (pprofListener != server.pprofServer.Addr) {
+			server.logger.Info("rehash", "Stopping pprof listener", server.pprofServer.Addr)
+			server.pprofServer.Close()
+			server.pprofServer = nil
+		}
+	}
+	if pprofListener != "" && server.pprofServer == nil {
+		ps := http.Server{
+			Addr: pprofListener,
+		}
+		go func() {
+			if err := ps.ListenAndServe(); err != nil {
+				server.logger.Error("rehash", fmt.Sprintf("pprof listener failed: %v", err))
+			}
+		}()
+		server.pprofServer = &ps
+		server.logger.Info("rehash", "Started pprof listener", server.pprofServer.Addr)
+	}
+}
+
 func (server *Server) loadMOTD(motdPath string, useFormatting bool) error {
 	server.logger.Info("rehash", "Using MOTD", motdPath)
 	motdLines := make([]string, 0)
diff --git a/oragono.yaml b/oragono.yaml
index 76d11980..b4875e4f 100644
--- a/oragono.yaml
+++ b/oragono.yaml
@@ -316,6 +316,12 @@ debug:
     # this to false.
     recover-from-errors: true
 
+    # optionally expose a pprof http endpoint: https://golang.org/pkg/net/http/pprof/
+    # it is strongly recommended that you don't expose this on a public interface;
+    # if you need to access it remotely, you can use an SSH tunnel.
+    # set to `null`, "", leave blank, or omit to disable
+    pprof-listener: "localhost:6060"
+
     # enabling StackImpact profiling
     stackimpact:
         # whether to use StackImpact

From 288203152a090f44650bd2f29c644f344cc3861f Mon Sep 17 00:00:00 2001
From: Shivaram Lingamneni <slingamn@cs.stanford.edu>
Date: Tue, 13 Mar 2018 18:04:15 -0400
Subject: [PATCH 2/2] comment out the pprof setting in the example config

---
 oragono.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/oragono.yaml b/oragono.yaml
index b4875e4f..af856724 100644
--- a/oragono.yaml
+++ b/oragono.yaml
@@ -320,7 +320,7 @@ debug:
     # it is strongly recommended that you don't expose this on a public interface;
     # if you need to access it remotely, you can use an SSH tunnel.
     # set to `null`, "", leave blank, or omit to disable
-    pprof-listener: "localhost:6060"
+    # pprof-listener: "localhost:6060"
 
     # enabling StackImpact profiling
     stackimpact: