From 42b8467bca48c7ebf30ae8e69e4edb4dbb9b2f1f Mon Sep 17 00:00:00 2001
From: Tharun <rajendrantharun@live.com>
Date: Sat, 3 Jul 2021 19:34:04 +0530
Subject: [PATCH 1/3] trigger reload configuration using SIGHUP

---
 cmd/agent/entrypoint.go | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/cmd/agent/entrypoint.go b/cmd/agent/entrypoint.go
index 98063dd92af1..9ff70b68e4fe 100644
--- a/cmd/agent/entrypoint.go
+++ b/cmd/agent/entrypoint.go
@@ -4,7 +4,10 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"os"
+	"os/signal"
 	"sync"
+	"syscall"
 
 	"github.com/gorilla/mux"
 	"github.com/grafana/agent/pkg/integrations"
@@ -230,6 +233,9 @@ func (ep *Entrypoint) Start() error {
 	// signal is received.
 	signalHandler := signals.NewHandler(ep.cfg.Server.Log)
 
+	notifier := make(chan os.Signal)
+	signal.Notify(notifier, syscall.SIGHUP)
+
 	g.Add(func() error {
 		signalHandler.Loop()
 		return nil
@@ -251,5 +257,11 @@ func (ep *Entrypoint) Start() error {
 		ep.srv.Close()
 	})
 
+	go func() {
+		for range notifier {
+			ep.TriggerReload()
+		}
+	}()
+
 	return g.Run()
 }

From 4eb24dcee79d62c927dfd7e4a585afce4bd3edbe Mon Sep 17 00:00:00 2001
From: Tharun <rajendrantharun@live.com>
Date: Tue, 6 Jul 2021 23:16:34 +0530
Subject: [PATCH 2/3] fix review changes - stop and close signal on defer

---
 cmd/agent/entrypoint.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/cmd/agent/entrypoint.go b/cmd/agent/entrypoint.go
index 9ff70b68e4fe..6746bf7bd3bb 100644
--- a/cmd/agent/entrypoint.go
+++ b/cmd/agent/entrypoint.go
@@ -236,6 +236,11 @@ func (ep *Entrypoint) Start() error {
 	notifier := make(chan os.Signal)
 	signal.Notify(notifier, syscall.SIGHUP)
 
+	defer func() {
+		signal.Stop(notifier)
+		close(notifier)
+	}()
+
 	g.Add(func() error {
 		signalHandler.Loop()
 		return nil

From e66075a33c63f7fabdc504ad9d2d14b69095f486 Mon Sep 17 00:00:00 2001
From: Tharun <rajendrantharun@live.com>
Date: Tue, 6 Jul 2021 23:31:37 +0530
Subject: [PATCH 3/3] add changelog for reloading config using SIGHUP

---
 CHANGELOG.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b494e9b847de..8b81781c36bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Main (unreleased)
 
+- [ENHANCEMENT] Allow reloading configuration using `SIGHUP` signal. (@tharun208)
+
 - [FEATURE] Add TLS config options for tempo `remote_write`s. (@mapno)
 
 - [FEATURE] Add support for OTLP HTTP trace exporting. (@mapno)