From b253ae8c8214629eba4aac0432b7e52055cfc37d Mon Sep 17 00:00:00 2001
From: Lucas Lara <lucaslorentzlara@hotmail.com>
Date: Tue, 12 Sep 2023 19:52:45 +0200
Subject: [PATCH] Allow customizing the throttle interval for events

---
 README.md         |  2 ++
 cmd.go            | 15 +++++++++++++++
 config/options.go |  1 +
 loader.go         |  2 +-
 4 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 90f67234..c409d2e7 100644
--- a/README.md
+++ b/README.md
@@ -501,6 +501,8 @@ Usage of docker-proxy:
         Which mode this instance should run: standalone | controller | server
   --polling-interval duration
         Interval Caddy should manually check Docker for a new Caddyfile (default 30s)
+  --event-throttle-interval duration
+        Interval to throttle caddyfile updates triggered by docker events (default 100ms)
   --process-caddyfile
         Process Caddyfile before loading it, removing invalid servers (default true)
   --proxy-service-tasks
diff --git a/cmd.go b/cmd.go
index 0b78e766..872fb9ed 100644
--- a/cmd.go
+++ b/cmd.go
@@ -64,6 +64,9 @@ func init() {
 			fs.Duration("polling-interval", 30*time.Second,
 				"Interval caddy should manually check docker for a new caddyfile")
 
+			fs.Duration("event-throttle-interval", 100*time.Millisecond,
+				"Interval to throttle caddyfile updates triggered by docker events")
+
 			return fs
 		}(),
 	})
@@ -143,6 +146,7 @@ func createOptions(flags caddycmd.Flags) *config.Options {
 	processCaddyfileFlag := flags.Bool("process-caddyfile")
 	scanStoppedContainersFlag := flags.Bool("scan-stopped-containers")
 	pollingIntervalFlag := flags.Duration("polling-interval")
+	eventThrottleIntervalFlag := flags.Duration("event-throttle-interval")
 	modeFlag := flags.String("mode")
 	controllerSubnetFlag := flags.String("controller-network")
 	dockerSocketsFlag := flags.String("docker-sockets")
@@ -254,5 +258,16 @@ func createOptions(flags caddycmd.Flags) *config.Options {
 		options.PollingInterval = pollingIntervalFlag
 	}
 
+	if eventThrottleIntervalEnv := os.Getenv("CADDY_DOCKER_EVENT_THROTTLE_INTERVAL"); eventThrottleIntervalEnv != "" {
+		if p, err := time.ParseDuration(eventThrottleIntervalEnv); err != nil {
+			log.Error("Failed to parse CADDY_DOCKER_EVENT_THROTTLE_INTERVAL", zap.String("CADDY_DOCKER_EVENT_THROTTLE_INTERVAL", eventThrottleIntervalEnv), zap.Error(err))
+			options.EventThrottleInterval = pollingIntervalFlag
+		} else {
+			options.EventThrottleInterval = p
+		}
+	} else {
+		options.EventThrottleInterval = eventThrottleIntervalFlag
+	}
+
 	return options
 }
diff --git a/config/options.go b/config/options.go
index 97defc61..92e3e12e 100644
--- a/config/options.go
+++ b/config/options.go
@@ -17,6 +17,7 @@ type Options struct {
 	ProcessCaddyfile       bool
 	ScanStoppedContainers  bool
 	PollingInterval        time.Duration
+	EventThrottleInterval  time.Duration
 	Mode                   Mode
 	Secret                 string
 	ControllerNetwork      *net.IPNet
diff --git a/loader.go b/loader.go
index 7777b899..ca875e66 100644
--- a/loader.go
+++ b/loader.go
@@ -209,7 +209,7 @@ func (dockerLoader *DockerLoader) listenEvents() {
 
 				if update {
 					dockerLoader.skipEvents[i] = true
-					dockerLoader.timer.Reset(100 * time.Millisecond)
+					dockerLoader.timer.Reset(dockerLoader.options.EventThrottleInterval)
 				}
 			case err := <-errorChan:
 				cancel()