From 4f0a42d1b4f7da3f9738b8647f1b6af22fd0f4b0 Mon Sep 17 00:00:00 2001
From: Nate Morse <morse255@umn.edu>
Date: Tue, 30 Dec 2025 10:27:34 -0600
Subject: [PATCH] Fix goroutine leak

This PR modifies the `Inform()` function to take in a [Context](https://pkg.go.dev/context) and exit when a signal comes in on the `ctx.Done()` channel. This fixes an issue where the goroutine is not cleaned up when a container restarts or is redeployed. Without this change, additional goroutines are spawned whenever a container restarts, and the previously spawned goroutine still remains active.
---
 maintenance.go | 48 +++++++++++++++++++++++++++---------------------
 1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/maintenance.go b/maintenance.go
index 76433b8..d233403 100644
--- a/maintenance.go
+++ b/maintenance.go
@@ -47,32 +47,38 @@ func CreateConfig() *Config {
 }
 
 // Inform if there are hosts in maintenance
-func Inform(config *Config) {
+func Inform(ctx context.Context, config *Config) {
 	t := time.NewTicker(time.Second * config.InformInterval)
 	defer t.Stop()
 
-	for ; true; <-t.C {
-		client := http.Client{
-			Timeout: time.Second * config.InformTimeout,
-		}
+	for {
+		select {
+		case <-t.C:
+			client := http.Client{
+				Timeout: time.Second * config.InformTimeout,
+			}
 
-		req, _ := http.NewRequest(http.MethodGet, config.InformUrl, nil)
-		res, doErr := client.Do(req)
-		if doErr != nil {
-			log.Printf("Inform: %v", doErr) // Don't fatal, just go further
-			continue
-		}
+			req, _ := http.NewRequest(http.MethodGet, config.InformUrl, nil)
+			res, doErr := client.Do(req)
+			if doErr != nil {
+				log.Printf("Inform: %v", doErr) // Don't fatal, just go further
+				continue
+			}
 
-		defer res.Body.Close()
+			defer res.Body.Close()
 
-		decoder := json.NewDecoder(res.Body)
-		decodeErr := decoder.Decode(&hosts)
-		if decodeErr != nil {
-			log.Printf("Inform: %v", decodeErr) // Don't fatal, just go further
-			continue
-		}
+			decoder := json.NewDecoder(res.Body)
+			decodeErr := decoder.Decode(&hosts)
+			if decodeErr != nil {
+				log.Printf("Inform: %v", decodeErr) // Don't fatal, just go further
+				continue
+			}
 
-		log.Printf("Inform response: %v", hosts)
+			log.Printf("Inform response: %v", hosts)
+		case <-ctx.Done():
+			log.Printf("Inform complete")
+			return
+		}
 	}
 }
 
@@ -137,8 +143,8 @@ func (rw *ResponseWriter) WriteHeader(statusCode int) {
 	rw.ResponseWriter.WriteHeader(http.StatusServiceUnavailable)
 }
 
-func New(_ context.Context, next http.Handler, config *Config, name string) (http.Handler, error) {
-	go Inform(config)
+func New(ctx context.Context, next http.Handler, config *Config, name string) (http.Handler, error) {
+	go Inform(ctx, config)
 
 	return &Maintenance{
 		name:   name,