Better error handling in restoring sandbox states

Signed-off-by: Madhu Venugopal <madhu@docker.com>

libnetwork/sandbox.go

@@ -726,6 +726,12 @@ func (sb *sandbox) restoreOslSandbox() error {
 		joinInfo := ep.joinInfo
 		i := ep.iface
 		ep.Unlock()
+
+		if i == nil {
+			log.Errorf("error restoring endpoint %s for container %s", ep.Name(), sb.ContainerID())
+			continue
+		}
+
 		ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().Address(i.addr), sb.osSbox.InterfaceOptions().Routes(i.routes))
 		if i.addrv6 != nil && i.addrv6.IP.To16() != nil {
 			ifaceOptions = append(ifaceOptions, sb.osSbox.InterfaceOptions().AddressIPv6(i.addrv6))

libnetwork/sandbox_store.go

@@ -245,6 +245,10 @@ func (c *controller) sandboxCleanup(activeSandboxes map[string]interface{}) {
 					ep = &endpoint{id: eps.Eid, network: n, sandboxID: sbs.ID}
 				}
 			}
+			if _, ok := activeSandboxes[sb.ID()]; ok && err != nil {
+				logrus.Errorf("failed to restore endpoint %s in %s for container %s due to %v", eps.Eid, eps.Nid, sb.ContainerID(), err)
+				continue
+			}
 			heap.Push(&sb.endpoints, ep)
 		}