DHCP lease maintenance should terminate when interface no longer exists.

Due to oberservations that threads can grow and the dhcp daemon uses an increasing amount of memory. This situation can happen organically when using say, bridge CNI, and the bridge has been removed outside of the bridge CNI lifecycle, and an interface no longer exists on a pod. Signed-off-by: dougbtv <[email protected]>
containernetworking · Jan 21, 2025 · 3cb9c6b · 3cb9c6b
1 parent e4ca66b
commit 3cb9c6b
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/plugins/ipam/dhcp/lease.go b/plugins/ipam/dhcp/lease.go
@@ -292,6 +292,11 @@ func (l *DHCPLease) maintain() {
 	for {
 		var sleepDur time.Duration
 
+		if _, err := netlink.LinkByName(l.link.Attrs().Name); err != nil {
+			log.Printf("%v: interface %s no longer exists, terminating lease maintenance", l.clientID, l.link.Attrs().Name)
+			return
+		}
+
 		switch state {
 		case leaseStateBound:
 			sleepDur = time.Until(l.renewalTime)
@@ -336,6 +341,7 @@ func (l *DHCPLease) maintain() {
 			log.Printf("%v: Checking lease", l.clientID)
 
 		case <-l.stop:
+			log.Printf("%v: received stop signal, releasing lease", l.clientID)
 			if err := l.release(); err != nil {
 				log.Printf("%v: failed to release DHCP lease: %v", l.clientID, err)
 			}