// 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)
}
示例#2
0
// ShouldUseIptablesProxier returns true if we should use the iptables Proxier
// instead of the "classic" userspace Proxier.  This is determined by checking
// the iptables version and for the existence of kernel features. It may return
// an error if it fails to get the itpables version without error, in which
// case it will also return false.
func ShouldUseIptablesProxier() (bool, error) {
	exec := utilexec.New()
	minVersion, err := semver.NewVersion(iptablesMinVersion)
	if err != nil {
		return false, err
	}
	// returns "X.X.X", err
	versionString, err := utiliptables.GetIptablesVersionString(exec)
	if err != nil {
		return false, err
	}
	version, err := semver.NewVersion(versionString)
	if err != nil {
		return false, err
	}
	if version.LessThan(*minVersion) {
		return false, nil
	}

	// Check for the required sysctls.  We don't care about the value, just
	// that it exists.  If this Proxier is chosen, we'll iniialize it as we
	// need.
	_, err = utilsysctl.GetSysctl(sysctlRouteLocalnet)
	if err != nil {
		return false, err
	}

	return true, nil
}