From 36d1c1512a0f8cc760f166bd0a59d8c504835b9e Mon Sep 17 00:00:00 2001
From: jbergner <jbergner@send.nrw>
Date: Mon, 29 Sep 2025 21:19:07 +0200
Subject: [PATCH] Node autocleanup

---
 cmd/unified/main.go   | 15 +++++++++
 internal/mesh/mesh.go | 76 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 90 insertions(+), 1 deletion(-)

diff --git a/cmd/unified/main.go b/cmd/unified/main.go
index aa278a7..b14dccf 100644
--- a/cmd/unified/main.go
+++ b/cmd/unified/main.go
@@ -22,6 +22,14 @@ import (
 	"git.send.nrw/sendnrw/decent-webui/internal/mesh"
 )
 
+func parseDuration(s string, def time.Duration) time.Duration {
+	d, err := time.ParseDuration(strings.TrimSpace(s))
+	if err != nil || d <= 0 {
+		return def
+	}
+	return d
+}
+
 /*** Config ***/
 func loadConfig() AppConfig {
 	// HTTP
@@ -44,6 +52,9 @@ func loadConfig() AppConfig {
 		DiscoveryAddress: getenvDefault("MESH_DISCOVERY_ADDR", "239.8.8.8:9898"),
 	}
 
+	m.PeerTTL = parseDuration(os.Getenv("MESH_PEER_TTL"), 2*time.Minute)
+	m.PruneInterval = parseDuration(os.Getenv("MESH_PRUNE_INTERVAL"), 30*time.Second)
+
 	// Wenn keine AdvertURL gesetzt ist, versuche eine sinnvolle Herleitung:
 	if strings.TrimSpace(m.AdvertURL) == "" {
 		m.AdvertURL = inferAdvertURL(m.BindAddr)
@@ -440,6 +451,10 @@ func main() {
 	if err != nil {
 		log.Fatalf("mesh init: %v", err)
 	}
+
+	// Hintergrund-Pruner starten
+	mnode.StartPeerPruner()
+
 	go func() {
 		log.Printf("[mesh] listening on %s advertise %s seeds=%v discovery=%v",
 			cfg.Mesh.BindAddr, cfg.Mesh.AdvertURL, cfg.Mesh.Seeds, cfg.Mesh.EnableDiscovery)
diff --git a/internal/mesh/mesh.go b/internal/mesh/mesh.go
index babee6d..1b18fc7 100644
--- a/internal/mesh/mesh.go
+++ b/internal/mesh/mesh.go
@@ -30,7 +30,9 @@ type Config struct {
 	Seeds            []string // other peers' mesh base URLs
 	ClusterSecret    string   // HMAC key
 	EnableDiscovery  bool
-	DiscoveryAddress string // "239.8.8.8:9898"
+	DiscoveryAddress string        // "239.8.8.8:9898"
+	PeerTTL          time.Duration // wie lange darf ein Peer inaktiv sein (Default siehe unten)
+	PruneInterval    time.Duration // wie oft wird gepruned
 }
 
 type Peer struct {
@@ -72,6 +74,78 @@ type Node struct {
 	wg     sync.WaitGroup
 }
 
+// RemovePeer löscht einen Peer aus der Peer-Tabelle. Seeds werden standardmäßig nicht entfernt.
+func (n *Node) RemovePeer(url string) bool {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	if url == "" || url == n.self.URL {
+		return false
+	}
+	// Seeds schützen
+	if n.isSeed(url) {
+		return false
+	}
+	if _, ok := n.peers[url]; ok {
+		delete(n.peers, url)
+		return true
+	}
+	return false
+}
+
+// PruneNow entfernt alle Peers, deren LastSeen vor cutoff liegt (Seeds bleiben).
+func (n *Node) PruneNow(cutoff time.Time) int {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+	removed := 0
+	for url, p := range n.peers {
+		if url == n.self.URL || n.isSeed(url) {
+			continue
+		}
+		if p.LastSeen.IsZero() || p.LastSeen.Before(cutoff) {
+			delete(n.peers, url)
+			removed++
+		}
+	}
+	return removed
+}
+
+// StartPeerPruner startet den Hintergrundjob (stoppt automatisch bei n.stop).
+func (n *Node) StartPeerPruner() {
+	go n.loopPrunePeers()
+}
+
+func (n *Node) loopPrunePeers() {
+	ttl := n.cfg.PeerTTL
+	if ttl <= 0 {
+		ttl = 2 * time.Minute
+	}
+	interval := n.cfg.PruneInterval
+	if interval <= 0 {
+		interval = 30 * time.Second
+	}
+	t := time.NewTicker(interval)
+	defer t.Stop()
+	for {
+		select {
+		case <-n.stop:
+			return
+		case <-t.C:
+			cutoff := time.Now().Add(-ttl)
+			_ = n.PruneNow(cutoff)
+		}
+	}
+}
+
+// helper: ist url ein Seed?
+func (n *Node) isSeed(url string) bool {
+	for _, s := range n.cfg.Seeds {
+		if strings.TrimSpace(s) == strings.TrimSpace(url) {
+			return true
+		}
+	}
+	return false
+}
+
 func New(cfg Config, cbs Callbacks) (*Node, error) {
 	if cfg.BindAddr == "" || cfg.AdvertURL == "" {
 		return nil, errors.New("mesh: BindAddr and AdvertURL required")