Golang netlink.NetworkLinkUp函數代碼示例

func InterfaceUp(name string) error {
	iface, err := net.InterfaceByName(name)
	if err != nil {
		return err
	}
	return netlink.NetworkLinkUp(iface)
}

// Setup networking
func setupNetworking(args *execdriver.InitArgs) error {
	if args.Ip != "" {
		// eth0
		iface, err := net.InterfaceByName("eth0")
		if err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		ip, ipNet, err := net.ParseCIDR(args.Ip)
		if err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		if err := netlink.NetworkLinkAddIp(iface, ip, ipNet); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		if err := netlink.NetworkSetMTU(iface, args.Mtu); err != nil {
			return fmt.Errorf("Unable to set MTU: %v", err)
		}
		if err := netlink.NetworkLinkUp(iface); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}

		// loopback
		iface, err = net.InterfaceByName("lo")
		if err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
		if err := netlink.NetworkLinkUp(iface); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
	}
	if args.Gateway != "" {
		gw := net.ParseIP(args.Gateway)
		if gw == nil {
			return fmt.Errorf("Unable to set up networking, %s is not a valid gateway IP", args.Gateway)
		}

		if err := netlink.AddDefaultGw(gw); err != nil {
			return fmt.Errorf("Unable to set up networking: %v", err)
		}
	}

	return nil
}

// CreateBridgeIface creates a network bridge interface on the host system with the name `ifaceName`,
// and attempts to configure it with an address which doesn't conflict with any other interface on the host.
// If it can't find an address which doesn't conflict, it will return an error.
func createBridge(bridgeIP string) error {
	nameservers := []string{}
	resolvConf, _ := resolvconf.Get()
	// we don't check for an error here, because we don't really care
	// if we can't read /etc/resolv.conf. So instead we skip the append
	// if resolvConf is nil. It either doesn't exist, or we can't read it
	// for some reason.
	if resolvConf != nil {
		nameservers = append(nameservers, resolvconf.GetNameserversAsCIDR(resolvConf)...)
	}

	var ifaceAddr string
	if len(bridgeIP) != 0 {
		_, _, err := net.ParseCIDR(bridgeIP)
		if err != nil {
			return err
		}
		ifaceAddr = bridgeIP
	} else {
		for _, addr := range addrs {
			_, dockerNetwork, err := net.ParseCIDR(addr)
			if err != nil {
				return err
			}
			if err := networkdriver.CheckNameserverOverlaps(nameservers, dockerNetwork); err == nil {
				if err := networkdriver.CheckRouteOverlaps(dockerNetwork); err == nil {
					ifaceAddr = addr
					break
				} else {
					utils.Debugf("%s %s", addr, err)
				}
			}
		}
	}

	if ifaceAddr == "" {
		return fmt.Errorf("Could not find a free IP address range for interface '%s'. Please configure its address manually and run 'docker -b %s'", bridgeIface, bridgeIface)
	}
	utils.Debugf("Creating bridge %s with network %s", bridgeIface, ifaceAddr)

	if err := createBridgeIface(bridgeIface); err != nil {
		return err
	}

	iface, err := net.InterfaceByName(bridgeIface)
	if err != nil {
		return err
	}

	ipAddr, ipNet, err := net.ParseCIDR(ifaceAddr)
	if err != nil {
		return err
	}

	if netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
		return fmt.Errorf("Unable to add private network: %s", err)
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to start network bridge: %s", err)
	}
	return nil
}

// CreateBridgeIface creates a network bridge interface on the host system with the name `ifaceName`,
// and attempts to configure it with an address which doesn't conflict with any other interface on the host.
// If it can't find an address which doesn't conflict, it will return an error.
func CreateBridgeIface(config *DaemonConfig) error {
	addrs := []string{
		// Here we don't follow the convention of using the 1st IP of the range for the gateway.
		// This is to use the same gateway IPs as the /24 ranges, which predate the /16 ranges.
		// In theory this shouldn't matter - in practice there's bound to be a few scripts relying
		// on the internal addressing or other stupid things like that.
		// The shouldn't, but hey, let's not break them unless we really have to.
		"172.17.42.1/16", // Don't use 172.16.0.0/16, it conflicts with EC2 DNS 172.16.0.23
		"10.0.42.1/16",   // Don't even try using the entire /8, that's too intrusive
		"10.1.42.1/16",
		"10.42.42.1/16",
		"172.16.42.1/24",
		"172.16.43.1/24",
		"172.16.44.1/24",
		"10.0.42.1/24",
		"10.0.43.1/24",
		"192.168.42.1/24",
		"192.168.43.1/24",
		"192.168.44.1/24",
	}

	nameservers := []string{}
	resolvConf, _ := utils.GetResolvConf()
	// we don't check for an error here, because we don't really care
	// if we can't read /etc/resolv.conf. So instead we skip the append
	// if resolvConf is nil. It either doesn't exist, or we can't read it
	// for some reason.
	if resolvConf != nil {
		nameservers = append(nameservers, utils.GetNameserversAsCIDR(resolvConf)...)
	}

	var ifaceAddr string
	if len(config.BridgeIp) != 0 {
		_, _, err := net.ParseCIDR(config.BridgeIp)
		if err != nil {
			return err
		}
		ifaceAddr = config.BridgeIp
	} else {
		for _, addr := range addrs {
			_, dockerNetwork, err := net.ParseCIDR(addr)
			if err != nil {
				return err
			}
			if err := networkdriver.CheckNameserverOverlaps(nameservers, dockerNetwork); err == nil {
				if err := networkdriver.CheckRouteOverlaps(dockerNetwork); err == nil {
					ifaceAddr = addr
					break
				} else {
					utils.Debugf("%s %s", addr, err)
				}
			}
		}
	}

	if ifaceAddr == "" {
		return fmt.Errorf("Could not find a free IP address range for interface '%s'. Please configure its address manually and run 'docker -b %s'", config.BridgeIface, config.BridgeIface)
	}
	utils.Debugf("Creating bridge %s with network %s", config.BridgeIface, ifaceAddr)

	if err := createBridgeIface(config.BridgeIface); err != nil {
		return err
	}
	iface, err := net.InterfaceByName(config.BridgeIface)
	if err != nil {
		return err
	}
	ipAddr, ipNet, err := net.ParseCIDR(ifaceAddr)
	if err != nil {
		return err
	}
	if netlink.NetworkLinkAddIp(iface, ipAddr, ipNet); err != nil {
		return fmt.Errorf("Unable to add private network: %s", err)
	}
	if err := netlink.NetworkLinkUp(iface); err != nil {
		return fmt.Errorf("Unable to start network bridge: %s", err)
	}

	return nil
}