호스트사이드 네트워크 설정기 제작

connet.service

@@ -9,15 +9,14 @@ DefaultDependencies=no
 After=systemd-udevd.service dbus.service network-pre.target systemd-sysusers.service systemd-sysctl.service
 Before=network.target multi-user.target shutdown.target
 Conflicts=shutdown.target
-Wants=network.target
+Wants=network-online.target
 
 
 [Service]
 # the VT is cleared by TTYVTDisallocate
 RemainAfterExit=yes
-#Environment=IP_ADDR= GATEWAY_ADDR=
 EnvironmentFile=/proc/1/environ
-ExecStart=/connet
+ExecStart=/usr/bin/connet
 Type=oneshot
 [Install]
 WantedBy=multi-user.target

gp/main.go

@@ -1,123 +1,419 @@
 package main
 
 import (
-    "github.com/vishvananda/netlink"
+	//	"github.com/ttacon/libphonenumber"
-    "io/ioutil"
+
-    "strings"
+	"bytes"
-    "net"
+	"errors"
-    "fmt"
+	"fmt"
-    "os"
+	"net"
-    "regexp"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"io/ioutil"
+
+	kingpin "gopkg.in/alecthomas/kingpin.v2"
+	"gopkg.in/yaml.v2"
+
+	"strconv"
+
+	errs "github.com/pkg/errors"
+	"github.com/vishvananda/netlink"
 )
 
-var env map[string]string=make(map[string]string)
+var (
+	app               = kingpin.New("plugin", "nspawn Bootstrapper.").Author("Sangbum Kim<sangbumkim@amuz.es>")
+	verbosePtr        = app.Flag("verbose", "Enable verbose mode.").Short('v').Bool()
+	clearPtr          = app.Flag("clear", "clear os environment.").Short('p').Bool()
+	nspawnPathPtr     = app.Flag("nspawn-path", "systemd-nspawn location.").Short('s').String()
+	containerHomePtr  = app.Flag("container-home", "container residence path").Default("/container").Short('d').String()
+	configFileNamePtr = app.Flag("config-file", "config file name").Default("settings.yml").HintOptions("FILENAME").Short('c').String()
+	nodeNamePtr       = app.Arg("nodeName", "nodename to spawn.").Required().String()
+	bindIfNamePtr     = app.Arg("bindInterface", "interface name to bind.").Required().String()
+)
 
-func main(){
+type mountPoint struct {
-   readInitEnviron()
+	Name     string `yaml:"name"`
-
+	Map      string `yaml:"map"`
-   macAddr,_ := net.ParseMAC(getEnv("IF_ADDR"))
+	Readonly bool   `yaml:"readonly"`
-//   fpAddr,_ := netlink.ParseAddr(getEnv("IP_ADDR"))
-//   gatewayAddr := net.ParseIP(getEnv("GATEWAY_ADDR"))
-
-   linkInterfaceType:=getEnvWithDefault("IF_TYPE","macvlan")
-
-   link:=findFirstInterface(linkInterfaceType)
-
-   renameInterface(link,"eth0")
-
-   renameMacAddress(link,macAddr)
-
-/*
-   #netlink.AddrAdd(link,ipAddr)
-
-   #netlink.LinkSetUp(link)
-
-   #addRoute(gatewayAddr,link)
-*/
 }
 
-func readInitEnviron(){
+func (mp mountPoint) Option(nodePath string) (option string, err error) {
-    envFilePath:="/proc/1/environ"
+	var mountPointPath string
-    content, err := ioutil.ReadFile(envFilePath)
+	if filepath.IsAbs(mp.Name){
-    kvParseRegex,_:=regexp.Compile("^([^=]+)=(.+)$")
+		mountPointPath= mp.Name
-    if err != nil {
+	}else{
-        panic(fmt.Sprintf("environ file  %s not existed!",envFilePath))
+		mountPointPath= filepath.Clean(filepath.Join(nodePath, "volume", mp.Name))
-    }
-    lines := strings.Split(string(content), "\x00")
-    for _,element := range lines {
-        result_slice := kvParseRegex.FindStringSubmatch(element)
-        if len(result_slice) < 2 {
-            continue
-        }else{
-            env[result_slice[1]]=result_slice[2]
-        }
-    }
-}
-func renameMacAddress(link netlink.Link,new_name net.HardwareAddr){
-  err:=netlink.LinkSetHardwareAddr(link,new_name)
-  if(err != nil){
-        panic(fmt.Sprintf("cannot rename mac address %s -> %s",link.Attrs().HardwareAddr,new_name))
-   } else {
-        fmt.Printf("rename mac address %s -> %s\n",link.Attrs().HardwareAddr,new_name)
-   }
-
-}
-
-func renameInterface(link netlink.Link,new_name string) {
-   err:=netlink.LinkSetName(link,new_name)
-   if(err != nil){
-        panic(fmt.Sprintf("cannot rename interface %s -> %s",link.Attrs().Name,new_name))
-   } else {
-        fmt.Printf("rename interface %s -> %s\n",link.Attrs().Name,new_name)
-   }
-}
-
-func findFirstInterface(if_type string) netlink.Link {
-   links,_:=netlink.LinkList()
-   for _,element := range links {
-       if(element.Type() == if_type){
-           fmt.Println(element.Attrs().Name)
-           return element
-       }
-   }
-   panic(fmt.Sprintf("cannot get type: %s interface",if_type))
-}
-
-func getEnv(variable string) string {
-   envValue,ok:=env[variable]
-   if ok {
-       return envValue
-   }
-   envValue=os.Getenv(variable)
-
-   if(envValue == ""){
-       panic(fmt.Sprintf("cannot get ${%s}",variable))
-   } else{
-       return envValue
-   }
-}
-
-func getEnvWithDefault(variable string, ret_is_empty string) string {
-   envValue,ok:=env[variable]
-   if ok {
-       return envValue
-   }
-   envValue=os.Getenv(variable)
-
-   if(envValue == ""){
-       return ret_is_empty
-   } else{
-       return envValue
-   }
-}
-
-func addRoute(gateway net.IP,link netlink.Link){
-	default_network := &net.IPNet{
-		IP:   net.IPv4(0, 0, 0, 0),
-		Mask: net.CIDRMask(0, 32),
 	}
 
-	route := &netlink.Route{LinkIndex: link.Attrs().Index, Dst: default_network, Gw:gateway}
+	if _, err = os.Stat(mountPointPath); os.IsNotExist(err) {
+		err = errors.New(fmt.Sprintf("mount point  %s is not exist", mountPointPath))
+		return
+	}
 
-	netlink.RouteAdd(route)
+	var buffer bytes.Buffer
+	if mp.Readonly {
+		buffer.WriteString("--bind-ro=")
+	} else {
+		buffer.WriteString("--bind=")
+	}
+	buffer.WriteString(mountPointPath)
+	buffer.WriteRune(':')
+	buffer.WriteString(mp.Map)
+	option = buffer.String()
+	return
 }
+func (mp mountPoint) String() string {
+	var buffer bytes.Buffer
+	buffer.WriteString(mp.Name)
+	if mp.Readonly {
+		buffer.WriteString("(readonly)")
+	}
+	buffer.WriteString("->")
+	buffer.WriteString(mp.Map)
+	return buffer.String()
+}
+
+type config struct {
+	MoundPoint []mountPoint `yaml:"mount-point"`
+}
+
+func (c config) String() string {
+	var buffer bytes.Buffer
+	buffer.WriteString("config:\n")
+	buffer.WriteString("  mount-point:\n")
+	for _, entry := range c.MoundPoint {
+		buffer.WriteString("    - ")
+		buffer.WriteString(entry.String())
+		buffer.WriteRune('\n')
+	}
+	return buffer.String()
+}
+
+// LookupIP looks up host using the local resolver.
+// It returns an array of that host's IPv4 and IPv6 addresses.
+func getIP(host string) (ip net.IP, err error) {
+	var addrs []net.IP
+	addrs, err = net.LookupIP(host)
+	if err != nil {
+		return
+	}
+	return addrs[0], nil
+}
+
+func getOutboundIPInfo(verbose bool) (gw net.IP, cidr uint64, linkname string, err error) {
+	// netlink.RouteList
+	var links []netlink.Link
+	links, err = netlink.LinkList()
+	if err != nil {
+		return
+	}
+
+	if verbose {
+		fmt.Println("scan system network interfaces:")
+	}
+	for _, link := range links {
+		attrs := link.Attrs()
+
+		if verbose {
+			fmt.Printf(" interface %s : ", attrs.Name)
+		}
+		if (attrs.Flags & net.FlagUp) == 0 {
+			if verbose {
+				fmt.Printf(" not up -- abandon!\n")
+			}
+			continue
+		} else {
+			if verbose {
+				fmt.Printf(" up!\n")
+			}
+		}
+
+		if verbose {
+			fmt.Println("   getting routing tables ")
+		}
+		var routes []netlink.Route
+		routes, err = netlink.RouteList(link, netlink.FAMILY_V4)
+		if err != nil {
+			continue
+		}
+		var (
+			matchedGw   net.IP
+			matchedCidr uint64
+			cidrOk      = false
+		)
+		for _, route := range routes {
+
+			if verbose {
+				fmt.Printf("     routing table %s\n", route.String())
+			}
+			if route.Dst == nil {
+				if verbose {
+					fmt.Printf("      - default gateway\n")
+				}
+				matchedGw = route.Gw
+				break
+			} else if verbose {
+				fmt.Printf("      - no default gateway\n")
+			}
+		}
+		if matchedGw == nil {
+			if verbose {
+				fmt.Println("     interface have not a default routing rule.")
+			}
+			continue
+		} else if verbose {
+			fmt.Printf("     interface have a default routing rule. gateway: %s", matchedGw.String())
+		}
+
+		if verbose {
+			fmt.Println("   getting networks ")
+		}
+		var networks []netlink.Addr
+		networks, err = netlink.AddrList(link, netlink.FAMILY_V4)
+		if err != nil {
+			fmt.Println("    - cannot getting networks ")
+			continue
+		}
+		for _, network := range networks {
+			if verbose {
+				fmt.Printf("     network %s\n", network.String())
+			}
+			if network.Contains(matchedGw) {
+				if verbose {
+					fmt.Printf("      - default network\n")
+				}
+				netSlice := strings.Split(network.IPNet.String(), "/")
+				if len(netSlice) < 2 {
+					continue
+				}
+				if cidrData, err := strconv.ParseUint(netSlice[len(netSlice)-1], 10, 64); err == nil {
+					matchedCidr = cidrData
+					cidrOk = true
+					break
+				}
+			} else if verbose {
+				fmt.Printf("      - no default network\n")
+			}
+		}
+		if cidrOk {
+			gw, cidr, linkname = matchedGw, matchedCidr, attrs.Name
+			if verbose {
+				fmt.Println(" ok! matched ")
+			}
+			break
+		} else if verbose {
+			fmt.Println("  abandon this interface ")
+		}
+	}
+	if gw == nil {
+		err = errors.New("default gateway or cidr not found!")
+	}
+
+	return
+}
+
+func checkInterfaceValid(bindIfName string) (err error) {
+	var link netlink.Link
+	link, err = netlink.LinkByName(bindIfName)
+
+	if err != nil {
+		return
+	}
+	attrs := link.Attrs()
+	if (attrs.Flags & net.FlagUp) == 0 {
+		err = errors.New("bind interface had been deactivated")
+	}
+	return
+}
+
+func checkNodeBasicDirectory(containerHomePath string, nodeName string, configFileName string) (nodePath string, nodeConfigPath string, err error) {
+	var containerHomeInfo os.FileInfo
+	if containerHomeInfo, err = os.Stat(containerHomePath); os.IsNotExist(err) {
+		err = errors.New(fmt.Sprintf("container home path %s is not exist", containerHomePath))
+		return
+	} else if !containerHomeInfo.IsDir() {
+		err = errors.New(fmt.Sprintf("container home path %s is not a directory", containerHomePath))
+		return
+	}
+
+	nodePath = filepath.Join(containerHomePath, nodeName)
+
+	var nodePathInfo os.FileInfo
+	if nodePathInfo, err = os.Stat(nodePath); os.IsNotExist(err) {
+		err = errors.New(fmt.Sprintf("node path %s is not exist", nodePath))
+		return
+	} else if !nodePathInfo.IsDir() {
+		err = errors.New(fmt.Sprintf("node path %s is not a directory", nodePath))
+		return
+	} else {
+		subDirNames := [...]string{"merge", "work", "delta"}
+		for _, subDirName := range subDirNames {
+			subPath := filepath.Join(nodePath, subDirName)
+
+			var subPathInfo os.FileInfo
+			if subPathInfo, err = os.Stat(subPath); os.IsNotExist(err) {
+				err = errors.New(fmt.Sprintf("sub path %s is not exist", subPath))
+				return
+			} else if !subPathInfo.IsDir() {
+				err = errors.New(fmt.Sprintf("sub path %s is not a directory", subPath))
+				return
+			}
+		}
+	}
+	nodeConfigPath = filepath.Join(containerHomePath, nodeName, configFileName)
+
+	var nodeConfigPathInfo os.FileInfo
+	if nodeConfigPathInfo, err = os.Stat(nodeConfigPath); os.IsNotExist(err) || nodeConfigPathInfo.IsDir() {
+		nodeConfigPath = ""
+	}
+
+	return
+
+}
+
+func LoadConfig(path string) (config config, err error) {
+	var (
+		source []byte
+	)
+	if path == "" {
+	} else if source, err = ioutil.ReadFile(path); err != nil {
+	} else if err = yaml.Unmarshal(source, &config); err != nil {
+	}
+	return
+}
+
+func main() {
+	_, err := app.Parse(os.Args[1:])
+	var (
+		verbose        = *verbosePtr
+		clear          = *clearPtr
+		nodeName       = *nodeNamePtr
+		bindIfName     = *bindIfNamePtr
+		configFileName = *configFileNamePtr
+		nspawnPath     string
+		progress       = -1
+	)
+
+	defer func() {
+		if r := recover(); r != nil {
+			fmt.Fprintln(os.Stderr, r)
+			os.Exit(progress)
+		}
+	}()
+	if err != nil {
+		panic(err)
+	}
+
+	progress = 1
+	containerHomePath, err := filepath.Abs(*containerHomePtr)
+	if err != nil {
+		panic(err)
+	}
+
+	progress++
+	nodePath, nodeConfigPath, err := checkNodeBasicDirectory(containerHomePath, nodeName, configFileName)
+	if err != nil {
+		panic(err)
+	} else if verbose {
+		var nodeConfigPathDesc = "not used"
+		if nodeConfigPath != "" {
+			nodeConfigPathDesc = nodeConfigPath
+		}
+		fmt.Printf(`sane container environment:
+  - container home : %s
+  - node home : %s
+  - node config : %s
+`, containerHomePath, nodePath, nodeConfigPathDesc)
+	}
+	config, err := LoadConfig(nodeConfigPath)
+	if err != nil {
+		panic(err)
+	} else if verbose {
+		fmt.Printf(config.String())
+	}
+
+	progress++
+
+	if nspawnPathPtr != nil && *nspawnPathPtr != "" {
+		nspawnPath = *nspawnPathPtr
+	} else if nspawnPathData, err := exec.LookPath("systemd-nspawn"); err != nil {
+		panic(errs.Wrap(err, "cannot find systemd-nspawn"))
+	} else {
+		nspawnPath = nspawnPathData
+		if verbose {
+			fmt.Printf("systemd-nspawn found : %s\n", nspawnPath)
+		}
+	}
+
+	progress++
+	err = checkInterfaceValid(bindIfName)
+	if err != nil {
+		panic(errs.Wrap(err, "error in checkInterfaceValid"))
+	}
+	progress++
+	nodeAddr, err := getIP(nodeName)
+
+	if err != nil {
+		panic(errs.Wrap(err, "error in getIP"))
+	}
+
+	progress++
+	gw, cidr, linkname, err := getOutboundIPInfo(verbose)
+	if err != nil {
+		panic(errs.Wrap(err, "error in getOutboundIPInfo"))
+	}
+
+	if verbose {
+		fmt.Println("network configuration:")
+		fmt.Printf("  - bind interface{%s} : valid\n", bindIfName)
+		fmt.Printf("  - default routing info : ip %s/%d link %s\n", gw.String(), cidr, linkname)
+		fmt.Printf("  - node{%s} IP address : %s\n", nodeName, nodeAddr.String())
+	}
+	option := []string{
+		"--quiet",
+		"--boot",
+		"--link-journal=try-host",
+		"--notify-ready=true"}
+	option = append(option, fmt.Sprintf("--network-ipvlan=%s", bindIfName))
+	option = append(option, fmt.Sprintf("--setenv=IP_ADDR=%s/%d", nodeAddr.String(), cidr))
+	option = append(option, fmt.Sprintf("--setenv=GATEWAY_ADDR=%s", gw.String()))
+	option = append(option, fmt.Sprintf("--machine=%s", nodeName))
+	option = append(option, fmt.Sprintf("--directory=%s", filepath.Join(nodePath, "merge")))
+
+	for _, mountPoint := range config.MoundPoint {
+		if mountOption, err := mountPoint.Option(nodePath); err != nil {
+			panic(errs.Wrap(err, "error in mountOption"))
+		} else {
+			option = append(option, mountOption)
+		}
+	}
+	var env []string
+	if clear {
+		env = []string{}
+	} else {
+		env = os.Environ()
+		if verbose {
+			fmt.Println("os environment:")
+			for _, segment := range env {
+				fmt.Println("  ", segment)
+			}
+		}
+	}
+	if verbose {
+		fmt.Println("systemd-nspawn spawning:")
+		fmt.Println(nspawnPath, " \\")
+		for _, segment := range option {
+			fmt.Println("  ", segment, " \\")
+		}
+		fmt.Println("  ;")
+	fmt.Println("bye!")
+	}
+	if err := syscall.Exec(nspawnPath, option, env); err != nil {
+		panic(errs.Wrap(err, "error in systemd-nspawn execution"))
+	}
+}
+

gp/src/github.com/vishvananda/netlink

@@ -1 +1 @@
-Subproject commit 814b43a0c71f01a137581a3fadf37619e71751b8
+Subproject commit 13fb20a9787c14bfc4c7996ce27d7224aa815812

main.go

@@ -15,25 +15,24 @@ var env map[string]string=make(map[string]string)
 func main(){
    readInitEnviron()
 
-   macAddr,_ := net.ParseMAC(getEnv("IF_ADDR"))
-//   fpAddr,_ := netlink.ParseAddr(getEnv("IP_ADDR"))
-//   gatewayAddr := net.ParseIP(getEnv("GATEWAY_ADDR"))
 
-   linkInterfaceType:=getEnvWithDefault("IF_TYPE","macvlan")
+   linkInterfaceType:=getEnvWithDefault("IF_TYPE","ipvlan")
 
    link:=findFirstInterface(linkInterfaceType)
 
    renameInterface(link,"eth0")
 
-   renameMacAddress(link,macAddr)
+   switch linkInterfaceType {
-
+   case "macvlan":
-/*
+     macAddr,_ := net.ParseMAC(getEnv("IF_ADDR"))
-   #netlink.AddrAdd(link,ipAddr)
+     renameMacAddress(link,macAddr)
-
+   case "ipvlan":
-   #netlink.LinkSetUp(link)
+     ipAddr,_ := netlink.ParseAddr(getEnv("IP_ADDR"))
-
+     gatewayAddr := net.ParseIP(getEnv("GATEWAY_ADDR"))
-   #addRoute(gatewayAddr,link)
+     netlink.AddrAdd(link,ipAddr)
-*/
+     netlink.LinkSetUp(link)
+     addRoute(gatewayAddr,link)
+  }
 }
 
 func readInitEnviron(){

plugin.go

@@ -0,0 +1,419 @@
+package main
+
+import (
+	//	"github.com/ttacon/libphonenumber"
+
+	"bytes"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"io/ioutil"
+
+	kingpin "gopkg.in/alecthomas/kingpin.v2"
+	"gopkg.in/yaml.v2"
+
+	"strconv"
+
+	errs "github.com/pkg/errors"
+	"github.com/vishvananda/netlink"
+)
+
+var (
+	app               = kingpin.New("plugin", "nspawn Bootstrapper.").Author("Sangbum Kim<sangbumkim@amuz.es>")
+	verbosePtr        = app.Flag("verbose", "Enable verbose mode.").Short('v').Bool()
+	clearPtr          = app.Flag("clear", "clear os environment.").Short('p').Bool()
+	nspawnPathPtr     = app.Flag("nspawn-path", "systemd-nspawn location.").Short('s').String()
+	containerHomePtr  = app.Flag("container-home", "container residence path").Default("/container").Short('d').String()
+	configFileNamePtr = app.Flag("config-file", "config file name").Default("settings.yml").HintOptions("FILENAME").Short('c').String()
+	nodeNamePtr       = app.Arg("nodeName", "nodename to spawn.").Required().String()
+	bindIfNamePtr     = app.Arg("bindInterface", "interface name to bind.").Required().String()
+)
+
+type mountPoint struct {
+	Name     string `yaml:"name"`
+	Map      string `yaml:"map"`
+	Readonly bool   `yaml:"readonly"`
+}
+
+func (mp mountPoint) Option(nodePath string) (option string, err error) {
+	var mountPointPath string
+	if filepath.IsAbs(mp.Name){
+		mountPointPath= mp.Name
+	}else{
+		mountPointPath= filepath.Clean(filepath.Join(nodePath, "volume", mp.Name))
+	}
+
+	if _, err = os.Stat(mountPointPath); os.IsNotExist(err) {
+		err = errors.New(fmt.Sprintf("mount point  %s is not exist", mountPointPath))
+		return
+	}
+
+	var buffer bytes.Buffer
+	if mp.Readonly {
+		buffer.WriteString("--bind-ro=")
+	} else {
+		buffer.WriteString("--bind=")
+	}
+	buffer.WriteString(mountPointPath)
+	buffer.WriteRune(':')
+	buffer.WriteString(mp.Map)
+	option = buffer.String()
+	return
+}
+func (mp mountPoint) String() string {
+	var buffer bytes.Buffer
+	buffer.WriteString(mp.Name)
+	if mp.Readonly {
+		buffer.WriteString("(readonly)")
+	}
+	buffer.WriteString("->")
+	buffer.WriteString(mp.Map)
+	return buffer.String()
+}
+
+type config struct {
+	MoundPoint []mountPoint `yaml:"mount-point"`
+}
+
+func (c config) String() string {
+	var buffer bytes.Buffer
+	buffer.WriteString("config:\n")
+	buffer.WriteString("  mount-point:\n")
+	for _, entry := range c.MoundPoint {
+		buffer.WriteString("    - ")
+		buffer.WriteString(entry.String())
+		buffer.WriteRune('\n')
+	}
+	return buffer.String()
+}
+
+// LookupIP looks up host using the local resolver.
+// It returns an array of that host's IPv4 and IPv6 addresses.
+func getIP(host string) (ip net.IP, err error) {
+	var addrs []net.IP
+	addrs, err = net.LookupIP(host)
+	if err != nil {
+		return
+	}
+	return addrs[0], nil
+}
+
+func getOutboundIPInfo(verbose bool) (gw net.IP, cidr uint64, linkname string, err error) {
+	// netlink.RouteList
+	var links []netlink.Link
+	links, err = netlink.LinkList()
+	if err != nil {
+		return
+	}
+
+	if verbose {
+		fmt.Println("scan system network interfaces:")
+	}
+	for _, link := range links {
+		attrs := link.Attrs()
+
+		if verbose {
+			fmt.Printf(" interface %s : ", attrs.Name)
+		}
+		if (attrs.Flags & net.FlagUp) == 0 {
+			if verbose {
+				fmt.Printf(" not up -- abandon!\n")
+			}
+			continue
+		} else {
+			if verbose {
+				fmt.Printf(" up!\n")
+			}
+		}
+
+		if verbose {
+			fmt.Println("   getting routing tables ")
+		}
+		var routes []netlink.Route
+		routes, err = netlink.RouteList(link, netlink.FAMILY_V4)
+		if err != nil {
+			continue
+		}
+		var (
+			matchedGw   net.IP
+			matchedCidr uint64
+			cidrOk      = false
+		)
+		for _, route := range routes {
+
+			if verbose {
+				fmt.Printf("     routing table %s\n", route.String())
+			}
+			if route.Dst == nil {
+				if verbose {
+					fmt.Printf("      - default gateway\n")
+				}
+				matchedGw = route.Gw
+				break
+			} else if verbose {
+				fmt.Printf("      - no default gateway\n")
+			}
+		}
+		if matchedGw == nil {
+			if verbose {
+				fmt.Println("     interface have not a default routing rule.")
+			}
+			continue
+		} else if verbose {
+			fmt.Printf("     interface have a default routing rule. gateway: %s", matchedGw.String())
+		}
+
+		if verbose {
+			fmt.Println("   getting networks ")
+		}
+		var networks []netlink.Addr
+		networks, err = netlink.AddrList(link, netlink.FAMILY_V4)
+		if err != nil {
+			fmt.Println("    - cannot getting networks ")
+			continue
+		}
+		for _, network := range networks {
+			if verbose {
+				fmt.Printf("     network %s\n", network.String())
+			}
+			if network.Contains(matchedGw) {
+				if verbose {
+					fmt.Printf("      - default network\n")
+				}
+				netSlice := strings.Split(network.IPNet.String(), "/")
+				if len(netSlice) < 2 {
+					continue
+				}
+				if cidrData, err := strconv.ParseUint(netSlice[len(netSlice)-1], 10, 64); err == nil {
+					matchedCidr = cidrData
+					cidrOk = true
+					break
+				}
+			} else if verbose {
+				fmt.Printf("      - no default network\n")
+			}
+		}
+		if cidrOk {
+			gw, cidr, linkname = matchedGw, matchedCidr, attrs.Name
+			if verbose {
+				fmt.Println(" ok! matched ")
+			}
+			break
+		} else if verbose {
+			fmt.Println("  abandon this interface ")
+		}
+	}
+	if gw == nil {
+		err = errors.New("default gateway or cidr not found!")
+	}
+
+	return
+}
+
+func checkInterfaceValid(bindIfName string) (err error) {
+	var link netlink.Link
+	link, err = netlink.LinkByName(bindIfName)
+
+	if err != nil {
+		return
+	}
+	attrs := link.Attrs()
+	if (attrs.Flags & net.FlagUp) == 0 {
+		err = errors.New("bind interface had been deactivated")
+	}
+	return
+}
+
+func checkNodeBasicDirectory(containerHomePath string, nodeName string, configFileName string) (nodePath string, nodeConfigPath string, err error) {
+	var containerHomeInfo os.FileInfo
+	if containerHomeInfo, err = os.Stat(containerHomePath); os.IsNotExist(err) {
+		err = errors.New(fmt.Sprintf("container home path %s is not exist", containerHomePath))
+		return
+	} else if !containerHomeInfo.IsDir() {
+		err = errors.New(fmt.Sprintf("container home path %s is not a directory", containerHomePath))
+		return
+	}
+
+	nodePath = filepath.Join(containerHomePath, nodeName)
+
+	var nodePathInfo os.FileInfo
+	if nodePathInfo, err = os.Stat(nodePath); os.IsNotExist(err) {
+		err = errors.New(fmt.Sprintf("node path %s is not exist", nodePath))
+		return
+	} else if !nodePathInfo.IsDir() {
+		err = errors.New(fmt.Sprintf("node path %s is not a directory", nodePath))
+		return
+	} else {
+		subDirNames := [...]string{"merge", "work", "delta"}
+		for _, subDirName := range subDirNames {
+			subPath := filepath.Join(nodePath, subDirName)
+
+			var subPathInfo os.FileInfo
+			if subPathInfo, err = os.Stat(subPath); os.IsNotExist(err) {
+				err = errors.New(fmt.Sprintf("sub path %s is not exist", subPath))
+				return
+			} else if !subPathInfo.IsDir() {
+				err = errors.New(fmt.Sprintf("sub path %s is not a directory", subPath))
+				return
+			}
+		}
+	}
+	nodeConfigPath = filepath.Join(containerHomePath, nodeName, configFileName)
+
+	var nodeConfigPathInfo os.FileInfo
+	if nodeConfigPathInfo, err = os.Stat(nodeConfigPath); os.IsNotExist(err) || nodeConfigPathInfo.IsDir() {
+		nodeConfigPath = ""
+	}
+
+	return
+
+}
+
+func LoadConfig(path string) (config config, err error) {
+	var (
+		source []byte
+	)
+	if path == "" {
+	} else if source, err = ioutil.ReadFile(path); err != nil {
+	} else if err = yaml.Unmarshal(source, &config); err != nil {
+	}
+	return
+}
+
+func main() {
+	_, err := app.Parse(os.Args[1:])
+	var (
+		verbose        = *verbosePtr
+		clear          = *clearPtr
+		nodeName       = *nodeNamePtr
+		bindIfName     = *bindIfNamePtr
+		configFileName = *configFileNamePtr
+		nspawnPath     string
+		progress       = -1
+	)
+
+	defer func() {
+		if r := recover(); r != nil {
+			fmt.Fprintln(os.Stderr, r)
+			os.Exit(progress)
+		}
+	}()
+	if err != nil {
+		panic(err)
+	}
+
+	progress = 1
+	containerHomePath, err := filepath.Abs(*containerHomePtr)
+	if err != nil {
+		panic(err)
+	}
+
+	progress++
+	nodePath, nodeConfigPath, err := checkNodeBasicDirectory(containerHomePath, nodeName, configFileName)
+	if err != nil {
+		panic(err)
+	} else if verbose {
+		var nodeConfigPathDesc = "not used"
+		if nodeConfigPath != "" {
+			nodeConfigPathDesc = nodeConfigPath
+		}
+		fmt.Printf(`sane container environment:
+  - container home : %s
+  - node home : %s
+  - node config : %s
+`, containerHomePath, nodePath, nodeConfigPathDesc)
+	}
+	config, err := LoadConfig(nodeConfigPath)
+	if err != nil {
+		panic(err)
+	} else if verbose {
+		fmt.Printf(config.String())
+	}
+
+	progress++
+
+	if nspawnPathPtr != nil && *nspawnPathPtr != "" {
+		nspawnPath = *nspawnPathPtr
+	} else if nspawnPathData, err := exec.LookPath("systemd-nspawn"); err != nil {
+		panic(errs.Wrap(err, "cannot find systemd-nspawn"))
+	} else {
+		nspawnPath = nspawnPathData
+		if verbose {
+			fmt.Printf("systemd-nspawn found : %s\n", nspawnPath)
+		}
+	}
+
+	progress++
+	err = checkInterfaceValid(bindIfName)
+	if err != nil {
+		panic(errs.Wrap(err, "error in checkInterfaceValid"))
+	}
+	progress++
+	nodeAddr, err := getIP(nodeName)
+
+	if err != nil {
+		panic(errs.Wrap(err, "error in getIP"))
+	}
+
+	progress++
+	gw, cidr, linkname, err := getOutboundIPInfo(verbose)
+	if err != nil {
+		panic(errs.Wrap(err, "error in getOutboundIPInfo"))
+	}
+
+	if verbose {
+		fmt.Println("network configuration:")
+		fmt.Printf("  - bind interface{%s} : valid\n", bindIfName)
+		fmt.Printf("  - default routing info : ip %s/%d link %s\n", gw.String(), cidr, linkname)
+		fmt.Printf("  - node{%s} IP address : %s\n", nodeName, nodeAddr.String())
+	}
+	option := []string{
+		"--quiet",
+		"--boot",
+		"--link-journal=try-host",
+		"--notify-ready=true"}
+	option = append(option, fmt.Sprintf("--network-ipvlan=%s", bindIfName))
+	option = append(option, fmt.Sprintf("--setenv=IP_ADDR=%s/%d", nodeAddr.String(), cidr))
+	option = append(option, fmt.Sprintf("--setenv=GATEWAY_ADDR=%s", gw.String()))
+	option = append(option, fmt.Sprintf("--machine=%s", nodeName))
+	option = append(option, fmt.Sprintf("--directory=%s", filepath.Join(nodePath, "merge")))
+
+	for _, mountPoint := range config.MoundPoint {
+		if mountOption, err := mountPoint.Option(nodePath); err != nil {
+			panic(errs.Wrap(err, "error in mountOption"))
+		} else {
+			option = append(option, mountOption)
+		}
+	}
+	var env []string
+	if clear {
+		env = []string{}
+	} else {
+		env = os.Environ()
+		if verbose {
+			fmt.Println("os environment:")
+			for _, segment := range env {
+				fmt.Println("  ", segment)
+			}
+		}
+	}
+	if verbose {
+		fmt.Println("systemd-nspawn spawning:")
+		fmt.Println(nspawnPath, " \\")
+		for _, segment := range option {
+			fmt.Println("  ", segment, " \\")
+		}
+		fmt.Println("  ;")
+	fmt.Println("bye!")
+	}
+	if err := syscall.Exec(nspawnPath, option, env); err != nil {
+		panic(errs.Wrap(err, "error in systemd-nspawn execution"))
+	}
+}
+