// setupKernelTunables validates kernel tunable flags are set as expected
// depending upon the specified option, it will either warn, error, or modify the kernel tunable flags
func setupKernelTunables(option KernelTunableBehavior) error {
	desiredState := map[string]int{
		utilsysctl.VmOvercommitMemory: utilsysctl.VmOvercommitMemoryAlways,
		utilsysctl.VmPanicOnOOM:       utilsysctl.VmPanicOnOOMInvokeOOMKiller,
	}

	errList := []error{}
	for flag, expectedValue := range desiredState {
		val, err := utilsysctl.GetSysctl(flag)
		if err != nil {
			errList = append(errList, err)
			continue
		}
		if val == expectedValue {
			continue
		}

		switch option {
		case KernelTunableError:
			errList = append(errList, fmt.Errorf("Invalid kernel flag: %v, expected value: %v, actual value: %v", flag, expectedValue, val))
		case KernelTunableWarn:
			glog.V(2).Infof("Invalid kernel flag: %v, expected value: %v, actual value: %v", flag, expectedValue, val)
		case KernelTunableModify:
			glog.V(2).Infof("Updating kernel flag: %v, expected value: %v, actual value: %v", flag, expectedValue, val)
			err = utilsysctl.SetSysctl(flag, expectedValue)
			if err != nil {
				errList = append(errList, err)
			}
		}
	}
	return errors.NewAggregate(errList)
}
Example #2
0
// NewProxier returns a new Proxier given an iptables Interface instance.
// Because of the iptables logic, it is assumed that there is only a single Proxier active on a machine.
// An error will be returned if iptables fails to update or acquire the initial lock.
// Once a proxier is created, it will keep iptables up to date in the background and
// will not terminate if a particular iptables call fails.
func NewProxier(ipt utiliptables.Interface, exec utilexec.Interface, syncPeriod time.Duration, masqueradeAll bool) (*Proxier, error) {
	// Set the route_localnet sysctl we need for
	if err := utilsysctl.SetSysctl(sysctlRouteLocalnet, 1); err != nil {
		return nil, fmt.Errorf("can't set sysctl %s: %v", sysctlRouteLocalnet, err)
	}

	// Load the module.  It's OK if this fails (e.g. the module is not present)
	// because we'll catch the error on the sysctl, which is what we actually
	// care about.
	exec.Command("modprobe", "br-netfilter").CombinedOutput()
	if err := utilsysctl.SetSysctl(sysctlBridgeCallIptables, 1); err != nil {
		glog.Warningf("can't set sysctl %s: %v", sysctlBridgeCallIptables, err)
	}

	return &Proxier{
		serviceMap:    make(map[proxy.ServicePortName]*serviceInfo),
		endpointsMap:  make(map[proxy.ServicePortName][]string),
		portsMap:      make(map[localPort]closeable),
		syncPeriod:    syncPeriod,
		iptables:      ipt,
		masqueradeAll: masqueradeAll,
	}, nil
}