Golang resolvconf.Build函数代码示例

func setupNetworking(config *Config) error {
	if config == nil {
		return nil
	}

	if len(config.DnsConfig.Nameservers) != 0 {
		if err := resolvconf.Build("/etc/resolv.conf", config.DnsConfig.Nameservers, config.DnsConfig.Search); err != nil {
			return err
		}
	}

	if config.BridgeName != "" {
		log.Debugf("Creating bridge %s (%s)", config.BridgeName, config.BridgeAddress)
		if err := netconf.ApplyNetworkConfigs(&netconf.NetworkConfig{
			Interfaces: map[string]netconf.InterfaceConfig{
				config.BridgeName: {
					Address: config.BridgeAddress,
					MTU:     config.BridgeMtu,
					Bridge:  true,
				},
			},
		}); err != nil {
			return err
		}
	}

	return nil
}

func (ep *endpoint) setupDNS() error {
	ep.Lock()
	container := ep.container
	joinInfo := ep.joinInfo
	ep.Unlock()

	if container == nil {
		return ErrNoContainer{}
	}

	if container.config.resolvConfPath == "" {
		container.config.resolvConfPath = defaultPrefix + "/" + container.id + "/resolv.conf"
	}

	dir, _ := filepath.Split(container.config.resolvConfPath)
	err := createBasePath(dir)
	if err != nil {
		return err
	}

	if joinInfo.resolvConfPath != "" {
		if err := copyFile(joinInfo.resolvConfPath, container.config.resolvConfPath); err != nil {
			return fmt.Errorf("could not copy source resolv.conf file %s to %s: %v", joinInfo.resolvConfPath, container.config.resolvConfPath, err)
		}

		return nil
	}

	resolvConf, err := resolvconf.Get()
	if err != nil {
		return err
	}

	if len(container.config.dnsList) > 0 ||
		len(container.config.dnsSearchList) > 0 {
		var (
			dnsList       = resolvconf.GetNameservers(resolvConf)
			dnsSearchList = resolvconf.GetSearchDomains(resolvConf)
		)

		if len(container.config.dnsList) > 0 {
			dnsList = container.config.dnsList
		}

		if len(container.config.dnsSearchList) > 0 {
			dnsSearchList = container.config.dnsSearchList
		}

		return resolvconf.Build(container.config.resolvConfPath, dnsList, dnsSearchList)
	}

	return ep.updateDNS(resolvConf)
}

func Main() {
	args := os.Args
	if len(args) > 1 {
		fmt.Println("call " + args[0] + " to load network config from cloud-config.yml")
		return
	}
	os.Remove(NETWORK_DONE) // ignore error
	cfg, err := config.LoadConfig()
	if err != nil {
		log.Fatal(err)
	}
	hostname, _ := cloudinit.SetHostname(cfg) // ignore error
	log.Infof("Network: hostname: '%s'", hostname)
	if err := netconf.ApplyNetworkConfigs(&cfg.Rancher.Network); err != nil {
		log.Error(err)
	}
	hostname, _ = cloudinit.SetHostname(cfg) // ignore error
	log.Infof("Network: hostname: '%s' (from DHCP, if not set by cloud-config)", hostname)
	if hostname != "" {
		hosts, err := os.Open("/etc/hosts")
		defer hosts.Close()
		if err != nil {
			log.Fatal(err)
		}
		lines := bufio.NewScanner(hosts)
		hostsContent := ""
		for lines.Scan() {
			line := strings.TrimSpace(lines.Text())
			fields := strings.Fields(line)
			if len(fields) > 0 && fields[0] == "127.0.1.1" {
				hostsContent += "127.0.1.1 " + hostname + "\n"
				continue
			}
			hostsContent += line + "\n"
		}
		if err := ioutil.WriteFile("/etc/hosts", []byte(hostsContent), 0600); err != nil {
			log.Error(err)
		}
	}
	if cfg.Rancher.Network.Dns.Override {
		log.WithFields(log.Fields{"nameservers": cfg.Rancher.Network.Dns.Nameservers}).Info("Override nameservers")
		if _, err := resolvconf.Build("/etc/resolv.conf", cfg.Rancher.Network.Dns.Nameservers, cfg.Rancher.Network.Dns.Search, nil); err != nil {
			log.Error(err)
		}
	}
	if f, err := os.Create(NETWORK_DONE); err != nil {
		log.Error(err)
	} else {
		f.Close()
	}
	sendTerm(WAIT_FOR_NETWORK)
	select {}
}

func (sb *sandbox) setupDNS() error {
	if sb.config.resolvConfPath == "" {
		sb.config.resolvConfPath = defaultPrefix + "/" + sb.id + "/resolv.conf"
	}

	sb.config.resolvConfHashFile = sb.config.resolvConfPath + ".hash"

	dir, _ := filepath.Split(sb.config.resolvConfPath)
	if err := createBasePath(dir); err != nil {
		return err
	}

	// This is for the host mode networking
	if sb.config.originResolvConfPath != "" {
		if err := copyFile(sb.config.originResolvConfPath, sb.config.resolvConfPath); err != nil {
			return fmt.Errorf("could not copy source resolv.conf file %s to %s: %v", sb.config.originResolvConfPath, sb.config.resolvConfPath, err)
		}
		return nil
	}

	resolvConf, err := resolvconf.Get()
	if err != nil {
		return err
	}
	dnsList := resolvconf.GetNameservers(resolvConf)
	dnsSearchList := resolvconf.GetSearchDomains(resolvConf)
	dnsOptionsList := resolvconf.GetOptions(resolvConf)

	if len(sb.config.dnsList) > 0 || len(sb.config.dnsSearchList) > 0 || len(dnsOptionsList) > 0 {
		if len(sb.config.dnsList) > 0 {
			dnsList = sb.config.dnsList
		}
		if len(sb.config.dnsSearchList) > 0 {
			dnsSearchList = sb.config.dnsSearchList
		}
		if len(sb.config.dnsOptionsList) > 0 {
			dnsOptionsList = sb.config.dnsOptionsList
		}
	}

	hash, err := resolvconf.Build(sb.config.resolvConfPath, dnsList, dnsSearchList, dnsOptionsList)
	if err != nil {
		return err
	}

	// write hash
	if err := ioutil.WriteFile(sb.config.resolvConfHashFile, []byte(hash), filePerm); err != nil {
		return types.InternalErrorf("failed to write resol.conf hash file when setting up dns for sandbox %s: %v", sb.ID(), err)
	}

	return nil
}

func Main() {
	flags.Parse(os.Args[1:])

	log.Infof("Running network: daemon=%v", daemon)

	os.Remove(NETWORK_DONE) // ignore error
	cfg, err := config.LoadConfig()
	if err != nil {
		log.Fatal(err)
	}

	nameservers := cfg.Rancher.Network.Dns.Nameservers
	search := cfg.Rancher.Network.Dns.Search
	userSetDns := len(nameservers) > 0 || len(search) > 0
	if !userSetDns {
		nameservers = cfg.Rancher.DefaultNetwork.Dns.Nameservers
		search = cfg.Rancher.DefaultNetwork.Dns.Search
	}

	if _, err := resolvconf.Build("/etc/resolv.conf", nameservers, search, nil); err != nil {
		log.Error(err)
	}

	if err := hostname.SetHostnameFromCloudConfig(cfg); err != nil {
		log.Error(err)
	}

	if err := netconf.ApplyNetworkConfigs(&cfg.Rancher.Network); err != nil {
		log.Error(err)
	}

	userSetHostname := cfg.Hostname != ""
	if err := netconf.RunDhcp(&cfg.Rancher.Network, !userSetHostname, !userSetDns); err != nil {
		log.Error(err)
	}

	if err := hostname.SyncHostname(); err != nil {
		log.Error(err)
	}

	if f, err := os.Create(NETWORK_DONE); err != nil {
		log.Error(err)
	} else {
		f.Close()
	}
	sendTerm(WAIT_FOR_NETWORK)

	if daemon {
		select {}
	}
}

// Embedded DNS server has to be enabled for this sandbox. Rebuild the container's
// resolv.conf by doing the following
// - Save the external name servers in resolv.conf in the sandbox
// - Add only the embedded server's IP to container's resolv.conf
// - If the embedded server needs any resolv.conf options add it to the current list
func (sb *sandbox) rebuildDNS() error {
	currRC, err := resolvconf.GetSpecific(sb.config.resolvConfPath)
	if err != nil {
		return err
	}

	// localhost entries have already been filtered out from the list
	// retain only the v4 servers in sb for forwarding the DNS queries
	sb.extDNS = resolvconf.GetNameservers(currRC.Content, types.IPv4)

	var (
		dnsList        = []string{sb.resolver.NameServer()}
		dnsOptionsList = resolvconf.GetOptions(currRC.Content)
		dnsSearchList  = resolvconf.GetSearchDomains(currRC.Content)
	)

	// external v6 DNS servers has to be listed in resolv.conf
	dnsList = append(dnsList, resolvconf.GetNameservers(currRC.Content, types.IPv6)...)

	// If the user config and embedded DNS server both have ndots option set,
	// remember the user's config so that unqualified names not in the docker
	// domain can be dropped.
	resOptions := sb.resolver.ResolverOptions()

dnsOpt:
	for _, resOpt := range resOptions {
		if strings.Contains(resOpt, "ndots") {
			for _, option := range dnsOptionsList {
				if strings.Contains(option, "ndots") {
					parts := strings.Split(option, ":")
					if len(parts) != 2 {
						return fmt.Errorf("invalid ndots option %v", option)
					}
					if num, err := strconv.Atoi(parts[1]); err != nil {
						return fmt.Errorf("invalid number for ndots option %v", option)
					} else if num > 0 {
						sb.ndotsSet = true
						break dnsOpt
					}
				}
			}
		}
	}

	dnsOptionsList = append(dnsOptionsList, resOptions...)

	_, err = resolvconf.Build(sb.config.resolvConfPath, dnsList, dnsSearchList, dnsOptionsList)
	return err
}

func (ep *endpoint) setupDNS() error {
	ep.Lock()
	container := ep.container
	ep.Unlock()

	if container == nil {
		return ErrNoContainer{}
	}

	if container.config.resolvConfPath == "" {
		container.config.resolvConfPath = defaultPrefix + "/" + container.id + "/resolv.conf"
	}

	dir, _ := filepath.Split(container.config.resolvConfPath)
	err := createBasePath(dir)
	if err != nil {
		return err
	}

	resolvConf, err := resolvconf.Get()
	if err != nil {
		return err
	}

	if len(container.config.dnsList) > 0 ||
		len(container.config.dnsSearchList) > 0 {
		var (
			dnsList       = resolvconf.GetNameservers(resolvConf)
			dnsSearchList = resolvconf.GetSearchDomains(resolvConf)
		)

		if len(container.config.dnsList) > 0 {
			dnsList = container.config.dnsList
		}

		if len(container.config.dnsSearchList) > 0 {
			dnsSearchList = container.config.dnsSearchList
		}

		return resolvconf.Build(container.config.resolvConfPath, dnsList, dnsSearchList)
	}

	return ep.updateDNS(resolvConf)
}

func setupNetworking(config *Config) error {
	if config == nil {
		return nil
	}

	hostname, err := os.Hostname()
	if err != nil {
		return err
	}
	tryCreateFile("/etc/hosts", `127.0.0.1    localhost
::1    localhost ip6-localhost ip6-loopback
fe00::0    ip6-localnet
ff00::0    ip6-mcastprefix
ff02::1    ip6-allnodes
ff02::2    ip6-allrouters

127.0.1.1       `+hostname)

	if len(config.DnsConfig.Nameservers) != 0 {
		if _, err := resolvconf.Build("/etc/resolv.conf", config.DnsConfig.Nameservers, config.DnsConfig.Search, nil); err != nil {
			return err
		}
	}

	if config.BridgeName != "" {
		log.Debugf("Creating bridge %s (%s)", config.BridgeName, config.BridgeAddress)
		if err := netconf.ApplyNetworkConfigs(&netconf.NetworkConfig{
			Interfaces: map[string]netconf.InterfaceConfig{
				config.BridgeName: {
					Address: config.BridgeAddress,
					MTU:     config.BridgeMtu,
					Bridge:  true,
				},
			},
		}); err != nil {
			return err
		}
	}

	return nil
}

// Embedded DNS server has to be enabled for this sandbox. Rebuild the container's
// resolv.conf by doing the follwing
// - Save the external name servers in resolv.conf in the sandbox
// - Add only the embedded server's IP to container's resolv.conf
// - If the embedded server needs any resolv.conf options add it to the current list
func (sb *sandbox) rebuildDNS() error {
	currRC, err := resolvconf.GetSpecific(sb.config.resolvConfPath)
	if err != nil {
		return err
	}

	// localhost entries have already been filtered out from the list
	sb.extDNS = resolvconf.GetNameservers(currRC.Content)

	var (
		dnsList        = []string{sb.resolver.NameServer()}
		dnsOptionsList = resolvconf.GetOptions(currRC.Content)
		dnsSearchList  = resolvconf.GetSearchDomains(currRC.Content)
	)

	// Resolver returns the options in the format resolv.conf expects
	dnsOptionsList = append(dnsOptionsList, sb.resolver.ResolverOptions()...)

	dir := path.Dir(sb.config.resolvConfPath)
	tmpResolvFile, err := ioutil.TempFile(dir, "resolv")
	if err != nil {
		return err
	}

	// Change the perms to filePerm (0644) since ioutil.TempFile creates it by default as 0600
	if err := os.Chmod(tmpResolvFile.Name(), filePerm); err != nil {
		return err
	}

	_, err = resolvconf.Build(tmpResolvFile.Name(), dnsList, dnsSearchList, dnsOptionsList)
	if err != nil {
		return err
	}

	return os.Rename(tmpResolvFile.Name(), sb.config.resolvConfPath)
}

func (sb *sandbox) setupDNS() error {
	var newRC *resolvconf.File

	if sb.config.resolvConfPath == "" {
		sb.config.resolvConfPath = defaultPrefix + "/" + sb.id + "/resolv.conf"
	}

	sb.config.resolvConfHashFile = sb.config.resolvConfPath + ".hash"

	dir, _ := filepath.Split(sb.config.resolvConfPath)
	if err := createBasePath(dir); err != nil {
		return err
	}

	// This is for the host mode networking
	if sb.config.originResolvConfPath != "" {
		if err := copyFile(sb.config.originResolvConfPath, sb.config.resolvConfPath); err != nil {
			return fmt.Errorf("could not copy source resolv.conf file %s to %s: %v", sb.config.originResolvConfPath, sb.config.resolvConfPath, err)
		}
		return nil
	}

	currRC, err := resolvconf.Get()
	if err != nil {
		return err
	}

	if len(sb.config.dnsList) > 0 || len(sb.config.dnsSearchList) > 0 || len(sb.config.dnsOptionsList) > 0 {
		var (
			err            error
			dnsList        = resolvconf.GetNameservers(currRC.Content, types.IP)
			dnsSearchList  = resolvconf.GetSearchDomains(currRC.Content)
			dnsOptionsList = resolvconf.GetOptions(currRC.Content)
		)
		if len(sb.config.dnsList) > 0 {
			dnsList = sb.config.dnsList
		}
		if len(sb.config.dnsSearchList) > 0 {
			dnsSearchList = sb.config.dnsSearchList
		}
		if len(sb.config.dnsOptionsList) > 0 {
			dnsOptionsList = sb.config.dnsOptionsList
		}
		newRC, err = resolvconf.Build(sb.config.resolvConfPath, dnsList, dnsSearchList, dnsOptionsList)
		if err != nil {
			return err
		}
		// After building the resolv.conf from the user config save the
		// external resolvers in the sandbox. Note that --dns 127.0.0.x
		// config refers to the loopback in the container namespace
		sb.setExternalResolvers(newRC.Content, types.IPv4, false)
	} else {
		// If the host resolv.conf file has 127.0.0.x container should
		// use the host restolver for queries. This is supported by the
		// docker embedded DNS server. Hence save the external resolvers
		// before filtering it out.
		sb.setExternalResolvers(currRC.Content, types.IPv4, true)

		// Replace any localhost/127.* (at this point we have no info about ipv6, pass it as true)
		if newRC, err = resolvconf.FilterResolvDNS(currRC.Content, true); err != nil {
			return err
		}
		// No contention on container resolv.conf file at sandbox creation
		if err := ioutil.WriteFile(sb.config.resolvConfPath, newRC.Content, filePerm); err != nil {
			return types.InternalErrorf("failed to write unhaltered resolv.conf file content when setting up dns for sandbox %s: %v", sb.ID(), err)
		}
	}

	// Write hash
	if err := ioutil.WriteFile(sb.config.resolvConfHashFile, []byte(newRC.Hash), filePerm); err != nil {
		return types.InternalErrorf("failed to write resolv.conf hash file when setting up dns for sandbox %s: %v", sb.ID(), err)
	}

	return nil
}