Merge pull request #13847 from hashicorp/gateway-goroutine-leak

Fix goroutine leaks in proxycfg when using ingress gateway

.changelog/13847.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+connect: Fixed a goroutine/memory leak that would occur when using the ingress gateway.
+```

agent/proxycfg/ingress_gateway.go

@@ -148,6 +148,16 @@ func (s *handlerIngressGateway) handleUpdate(ctx context.Context, u UpdateEvent,
 
 		for uid, cancelFn := range snap.IngressGateway.WatchedDiscoveryChains {
 			if _, ok := watchedSvcs[uid]; !ok {
+				for targetID, cancelUpstreamFn := range snap.IngressGateway.WatchedUpstreams[uid] {
+					s.logger.Debug("stopping watch of target",
+						"upstream", uid,
+						"target", targetID,
+					)
+					delete(snap.IngressGateway.WatchedUpstreams[uid], targetID)
+					delete(snap.IngressGateway.WatchedUpstreamEndpoints[uid], targetID)
+					cancelUpstreamFn()
+				}
+
 				cancelFn()
 				delete(snap.IngressGateway.WatchedDiscoveryChains, uid)
 			}

agent/proxycfg/upstreams.go

@@ -436,7 +436,17 @@ type discoveryChainWatchOpts struct {
 }
 
 func (s *handlerUpstreams) watchDiscoveryChain(ctx context.Context, snap *ConfigSnapshot, opts discoveryChainWatchOpts) error {
-	if _, ok := snap.ConnectProxy.WatchedDiscoveryChains[opts.id]; ok {
+	var watchedDiscoveryChains map[UpstreamID]context.CancelFunc
+	switch s.kind {
+	case structs.ServiceKindIngressGateway:
+		watchedDiscoveryChains = snap.IngressGateway.WatchedDiscoveryChains
+	case structs.ServiceKindConnectProxy:
+		watchedDiscoveryChains = snap.ConnectProxy.WatchedDiscoveryChains
+	default:
+		return fmt.Errorf("unsupported kind %s", s.kind)
+	}
+
+	if _, ok := watchedDiscoveryChains[opts.id]; ok {
 		return nil
 	}
 
@@ -457,16 +467,7 @@ func (s *handlerUpstreams) watchDiscoveryChain(ctx context.Context, snap *Config
 		return err
 	}
 
-	switch s.kind {
+	watchedDiscoveryChains[opts.id] = cancel
-	case structs.ServiceKindIngressGateway:
-		snap.IngressGateway.WatchedDiscoveryChains[opts.id] = cancel
-	case structs.ServiceKindConnectProxy:
-		snap.ConnectProxy.WatchedDiscoveryChains[opts.id] = cancel
-	default:
-		cancel()
-		return fmt.Errorf("unsupported kind %s", s.kind)
-	}
-
 	return nil
 }