Golang Interface.Command方法代码示例

// 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) (*Proxier, error) {

	// Set the route_localnet sysctl we need for
	if err := 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 := setSysctl(sysctlBridgeCallIptables, 1); err != nil {
		return nil, fmt.Errorf("can't set sysctl %s: %v", sysctlBridgeCallIptables, err)
	}

	// No turning back. Remove artifacts that might still exist from the userspace Proxier.
	glog.V(2).Info("Tearing down userspace rules. Errors here are acceptable.")
	tearDownUserspaceIptables(ipt)

	return &Proxier{
		serviceMap: make(map[proxy.ServicePortName]*serviceInfo),
		syncPeriod: syncPeriod,
		iptables:   ipt,
	}, nil
}

func findPairInterfaceOfContainerInterface(e exec.Interface, containerInterfaceName, containerDesc string, nsenterArgs []string) (string, error) {
	nsenterPath, err := e.LookPath("nsenter")
	if err != nil {
		return "", err
	}
	ethtoolPath, err := e.LookPath("ethtool")
	if err != nil {
		return "", err
	}

	nsenterArgs = append(nsenterArgs, "-F", "--", ethtoolPath, "--statistics", containerInterfaceName)
	output, err := e.Command(nsenterPath, nsenterArgs...).CombinedOutput()
	if err != nil {
		return "", fmt.Errorf("Unable to query interface %s of container %s: %v: %s", containerInterfaceName, containerDesc, err, string(output))
	}
	// look for peer_ifindex
	match := ethtoolOutputRegex.FindSubmatch(output)
	if match == nil {
		return "", fmt.Errorf("No peer_ifindex in interface statistics for %s of container %s", containerInterfaceName, containerDesc)
	}
	peerIfIndex, err := strconv.Atoi(string(match[1]))
	if err != nil { // seems impossible (\d+ not numeric)
		return "", fmt.Errorf("peer_ifindex wasn't numeric: %s: %v", match[1], err)
	}
	iface, err := net.InterfaceByIndex(peerIfIndex)
	if err != nil {
		return "", err
	}
	return iface.Name, nil
}

// 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, masqueradeBit int) (*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)
	}

	// Generate the masquerade mark to use for SNAT rules.
	if masqueradeBit < 0 || masqueradeBit > 31 {
		return nil, fmt.Errorf("invalid iptables-masquerade-bit %v not in [0, 31]", masqueradeBit)
	}
	masqueradeValue := 1 << uint(masqueradeBit)
	masqueradeMark := fmt.Sprintf("%#08x/%#08x", masqueradeValue, masqueradeValue)

	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,
		masqueradeMark: masqueradeMark,
	}, nil
}

// Runs "iptables --version" to get the version string
func getIptablesVersionString(exec utilexec.Interface) (string, error) {
	// this doesn't access mutable state so we don't need to use the interface / runner
	bytes, err := exec.Command(cmdIptables, "--version").CombinedOutput()
	if err != nil {
		return "", err
	}
	return string(bytes), nil
}

// Runs "iptables --version" to get the version string
func getIptablesVersionString(exec utilexec.Interface) (string, error) {
	bytes, err := exec.Command("iptables", "--version").CombinedOutput()
	if err != nil {
		return "", err
	}

	return string(bytes), nil
}

// given a LUN find the VHD device path like /dev/sdb
// VHD disks under sysfs are like /sys/bus/scsi/devices/3:0:1:0
// return empty string if no disk is found
func findDiskByLun(lun int, io ioHandler, exe exec.Interface) (string, error) {
	var err error
	sys_path := "/sys/bus/scsi/devices"
	if dirs, err := io.ReadDir(sys_path); err == nil {
		for _, f := range dirs {
			name := f.Name()
			// look for path like /sys/bus/scsi/devices/3:0:1:0
			arr := strings.Split(name, ":")
			if len(arr) < 4 {
				continue
			}
			target, err := strconv.Atoi(arr[0])
			if err != nil {
				glog.Errorf("failed to parse target from %v (%v), err %v", arr[0], name, err)
				continue
			}

			// as observed, targets 0-3 are used by OS disks. Skip them
			if target > 3 {
				l, err := strconv.Atoi(arr[3])
				if err != nil {
					// unknown path format, continue to read the next one
					glog.Errorf("failed to parse lun from %v (%v), err %v", arr[3], name, err)
					continue
				}
				if lun == l {
					// find the matching LUN
					// read vendor and model to ensure it is a VHD disk
					vendor := path.Join(sys_path, name, "vendor")
					model := path.Join(sys_path, name, "model")
					out, err := exe.Command("cat", vendor, model).CombinedOutput()
					if err != nil {
						glog.Errorf("failed to cat device vendor and model, err: %v", err)
						continue
					}
					matched, err := regexp.MatchString("^MSFT[ ]{0,}\nVIRTUAL DISK[ ]{0,}\n$", strings.ToUpper(string(out)))
					if err != nil || !matched {
						glog.V(4).Infof("doesn't match VHD, output %v, error %v", string(out), err)
						continue
					}
					// find it!
					dir := path.Join(sys_path, name, "block")
					dev, err := io.ReadDir(dir)
					if err != nil {
						glog.Errorf("failed to read %s", dir)
					} else {
						return "/dev/" + dev[0].Name(), nil
					}
				}
			}
		}
	}
	return "", err
}

// getIptablesVersionString runs "iptables --version" to get the version string
// in the form "X.X.X"
func getIptablesVersionString(exec utilexec.Interface) (string, error) {
	// this doesn't access mutable state so we don't need to use the interface / runner
	bytes, err := exec.Command(cmdIptables, "--version").CombinedOutput()
	if err != nil {
		return "", err
	}
	versionMatcher := regexp.MustCompile("v([0-9]+\\.[0-9]+\\.[0-9]+)")
	match := versionMatcher.FindStringSubmatch(string(bytes))
	if match == nil {
		return "", fmt.Errorf("no iptables version found in string: %s", bytes)
	}
	return match[1], nil
}

// 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 := 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 := setSysctl(sysctlBridgeCallIptables, 1); err != nil {
		return nil, fmt.Errorf("can't set sysctl %s: %v", sysctlBridgeCallIptables, err)
	}

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

func getOnePodIP(execer utilexec.Interface, nsenterPath, netnsPath, interfaceName, addrType string) (net.IP, error) {
	// Try to retrieve ip inside container network namespace
	output, err := execer.Command(nsenterPath, fmt.Sprintf("--net=%s", netnsPath), "-F", "--",
		"ip", "-o", addrType, "addr", "show", "dev", interfaceName, "scope", "global").CombinedOutput()
	if err != nil {
		return nil, fmt.Errorf("Unexpected command output %s with error: %v", output, err)
	}

	lines := strings.Split(string(output), "\n")
	if len(lines) < 1 {
		return nil, fmt.Errorf("Unexpected command output %s", output)
	}
	fields := strings.Fields(lines[0])
	if len(fields) < 4 {
		return nil, fmt.Errorf("Unexpected address output %s ", lines[0])
	}
	ip, _, err := net.ParseCIDR(fields[3])
	if err != nil {
		return nil, fmt.Errorf("CNI failed to parse ip from output %s due to %v", output, err)
	}

	return ip, nil
}