feat(interfaces): Add support for interfaces file

This adds the ability for cloudinit to parse a debian interfaces
file and generate the coresponding networkd configs.
This commit is contained in:
Alex Crawford 2014-05-22 13:42:09 -07:00
parent f8a823cf7e
commit 38321fedce
3 changed files with 574 additions and 0 deletions

193
network/interface.go Normal file
View File

@ -0,0 +1,193 @@
package network
import (
"fmt"
"strconv"
)
type InterfaceGenerator interface {
Name() string
Netdev() string
Link() string
Network() string
}
type logicalInterface struct {
name string
config configMethod
children []InterfaceGenerator
}
func (i *logicalInterface) Network() string {
config := fmt.Sprintf("[Match]\nName=%s\n\n[Network]\n", i.name)
for _, child := range i.children {
switch iface := child.(type) {
case *vlanInterface:
config += fmt.Sprintf("VLAN=%s\n", iface.name)
case *bondInterface:
config += fmt.Sprintf("Bond=%s\n", iface.name)
}
}
switch conf := i.config.(type) {
case configMethodStatic:
for _, nameserver := range conf.nameservers {
config += fmt.Sprintf("DNS=%s\n", nameserver)
}
if conf.address.IP != nil {
config += fmt.Sprintf("\n[Address]\nAddress=%s\n", conf.address.String())
}
for _, route := range conf.routes {
config += fmt.Sprintf("\n[Route]\nDestination=%s\nGateway=%s\n", route.destination.String(), route.gateway)
}
case configMethodDHCP:
config += "DHCP=true\n"
}
return config
}
type physicalInterface struct {
logicalInterface
}
func (p *physicalInterface) Name() string {
return p.name
}
func (p *physicalInterface) Netdev() string {
return ""
}
func (p *physicalInterface) Link() string {
return ""
}
type bondInterface struct {
logicalInterface
slaves []string
}
func (b *bondInterface) Name() string {
return b.name
}
func (b *bondInterface) Netdev() string {
return fmt.Sprintf("[NetDev]\nKind=bond\nName=%s\n", b.name)
}
func (b *bondInterface) Link() string {
return ""
}
type vlanInterface struct {
logicalInterface
id int
rawDevice string
}
func (v *vlanInterface) Name() string {
return v.name
}
func (v *vlanInterface) Netdev() string {
return fmt.Sprintf("[NetDev]\nKind=vlan\nName=%s\n\n[VLAN]\nId=%d\n", v.name, v.id)
}
func (v *vlanInterface) Link() string {
return ""
}
func buildInterfaces(stanzas []*stanzaInterface) []InterfaceGenerator {
bondStanzas := make(map[string]*stanzaInterface)
physicalStanzas := make(map[string]*stanzaInterface)
vlanStanzas := make(map[string]*stanzaInterface)
for _, iface := range stanzas {
switch iface.kind {
case interfaceBond:
bondStanzas[iface.name] = iface
case interfacePhysical:
physicalStanzas[iface.name] = iface
case interfaceVLAN:
vlanStanzas[iface.name] = iface
}
}
physicals := make(map[string]*physicalInterface)
for _, p := range physicalStanzas {
if _, ok := p.configMethod.(configMethodLoopback); ok {
continue
}
physicals[p.name] = &physicalInterface{
logicalInterface{
name: p.name,
config: p.configMethod,
children: []InterfaceGenerator{},
},
}
}
bonds := make(map[string]*bondInterface)
for _, b := range bondStanzas {
bonds[b.name] = &bondInterface{
logicalInterface{
name: b.name,
config: b.configMethod,
children: []InterfaceGenerator{},
},
b.options["slaves"],
}
}
vlans := make(map[string]*vlanInterface)
for _, v := range vlanStanzas {
var rawDevice string
id, _ := strconv.Atoi(v.options["id"][0])
if device := v.options["raw_device"]; len(device) == 1 {
rawDevice = device[0]
}
vlans[v.name] = &vlanInterface{
logicalInterface{
name: v.name,
config: v.configMethod,
children: []InterfaceGenerator{},
},
id,
rawDevice,
}
}
for _, vlan := range vlans {
if physical, ok := physicals[vlan.rawDevice]; ok {
physical.children = append(physical.children, vlan)
}
if bond, ok := bonds[vlan.rawDevice]; ok {
bond.children = append(bond.children, vlan)
}
}
for _, bond := range bonds {
for _, slave := range bond.slaves {
if physical, ok := physicals[slave]; ok {
physical.children = append(physical.children, bond)
}
if pBond, ok := bonds[slave]; ok {
pBond.children = append(pBond.children, bond)
}
}
}
interfaces := make([]InterfaceGenerator, 0, len(physicals)+len(bonds)+len(vlans))
for _, physical := range physicals {
interfaces = append(interfaces, physical)
}
for _, bond := range bonds {
interfaces = append(interfaces, bond)
}
for _, vlan := range vlans {
interfaces = append(interfaces, vlan)
}
return interfaces
}

86
network/network.go Normal file
View File

@ -0,0 +1,86 @@
package network
import (
"fmt"
"io"
"os"
"path"
"strings"
)
func ProcessDebianNetconf(config string) ([]InterfaceGenerator, error) {
lines := formatConfig(config)
stanzas, err := parseStanzas(lines)
if err != nil {
return nil, err
}
interfaces := make([]*stanzaInterface, 0, len(stanzas))
for _, stanza := range stanzas {
switch s := stanza.(type) {
case *stanzaInterface:
interfaces = append(interfaces, s)
}
}
return buildInterfaces(interfaces), nil
}
func WriteConfigs(configPath string, interfaces []InterfaceGenerator) error {
if err := os.MkdirAll(configPath, os.ModePerm+os.ModeDir); err != nil {
fmt.Println(err)
os.Exit(1)
}
for _, iface := range interfaces {
filename := path.Join(configPath, fmt.Sprintf("%s.netdev", iface.Name()))
if err := writeConfig(filename, iface.GenerateNetdevConfig()); err != nil {
return err
}
filename = path.Join(configPath, fmt.Sprintf("%s.link", iface.Name()))
if err := writeConfig(filename, iface.GenerateLinkConfig()); err != nil {
return err
}
filename = path.Join(configPath, fmt.Sprintf("%s.network", iface.Name()))
if err := writeConfig(filename, iface.GenerateNetworkConfig()); err != nil {
return err
}
}
return nil
}
func writeConfig(filename string, config string) error {
if config == "" {
return nil
}
if file, err := os.Create(filename); err == nil {
io.WriteString(file, config)
file.Close()
return nil
} else {
return err
}
}
func formatConfig(config string) []string {
lines := []string{}
config = strings.Replace(config, "\\\n", "", -1)
for config != "" {
split := strings.SplitN(config, "\n", 2)
line := strings.TrimSpace(split[0])
if len(split) == 2 {
config = split[1]
} else {
config = ""
}
if strings.HasPrefix(line, "#") || line == "" {
continue
}
lines = append(lines, line)
}
return lines
}

295
network/stanza.go Normal file
View File

@ -0,0 +1,295 @@
package network
import (
"fmt"
"net"
"strconv"
"strings"
)
type stanza interface{}
type stanzaAuto struct {
interfaces []string
}
type stanzaInterface struct {
name string
kind interfaceKind
auto bool
configMethod configMethod
options map[string][]string
}
type interfaceKind int
const (
interfaceBond = interfaceKind(iota)
interfacePhysical
interfaceVLAN
)
type route struct {
destination net.IPNet
gateway net.IP
}
type configMethod interface{}
type configMethodStatic struct {
address net.IPNet
nameservers []net.IP
routes []route
}
type configMethodLoopback struct{}
type configMethodManual struct{}
type configMethodDHCP struct{}
func parseStanzas(lines []string) (stanzas []stanza, err error) {
rawStanzas, err := splitStanzas(lines)
if err != nil {
return nil, err
}
stanzas = make([]stanza, 0, len(rawStanzas))
for _, rawStanza := range rawStanzas {
if stanza, err := parseStanza(rawStanza); err == nil {
stanzas = append(stanzas, stanza)
} else {
return nil, err
}
}
autos := make([]string, 0)
interfaceMap := make(map[string]*stanzaInterface)
for _, stanza := range stanzas {
switch c := stanza.(type) {
case *stanzaAuto:
autos = append(autos, c.interfaces...)
case *stanzaInterface:
interfaceMap[c.name] = c
}
}
// Apply the auto attribute
for _, auto := range autos {
if iface, ok := interfaceMap[auto]; ok {
iface.auto = true
}
}
return stanzas, nil
}
func splitStanzas(lines []string) ([][]string, error) {
var curStanza []string
stanzas := make([][]string, 0)
for _, line := range lines {
if isStanzaStart(line) {
if curStanza != nil {
stanzas = append(stanzas, curStanza)
}
curStanza = []string{line}
} else if curStanza != nil {
curStanza = append(curStanza, line)
} else {
return nil, fmt.Errorf("missing stanza start '%s'", line)
}
}
if curStanza != nil {
stanzas = append(stanzas, curStanza)
}
return stanzas, nil
}
func isStanzaStart(line string) bool {
switch strings.Split(line, " ")[0] {
case "auto":
fallthrough
case "iface":
fallthrough
case "mapping":
return true
}
if strings.HasPrefix(line, "allow-") {
return true
}
return false
}
func parseStanza(rawStanza []string) (stanza, error) {
if len(rawStanza) == 0 {
panic("empty stanza")
}
tokens := strings.Fields(rawStanza[0])
if len(tokens) < 2 {
return nil, fmt.Errorf("malformed stanza start %q", rawStanza[0])
}
kind := tokens[0]
attributes := tokens[1:]
switch kind {
case "auto":
return parseAutoStanza(attributes, rawStanza[1:])
case "iface":
return parseInterfaceStanza(attributes, rawStanza[1:])
default:
return nil, fmt.Errorf("unknown stanza '%s'", kind)
}
}
func parseAutoStanza(attributes []string, options []string) (*stanzaAuto, error) {
return &stanzaAuto{interfaces: attributes}, nil
}
func parseInterfaceStanza(attributes []string, options []string) (*stanzaInterface, error) {
if len(attributes) != 3 {
return nil, fmt.Errorf("incorrect number of attributes")
}
iface := attributes[0]
confMethod := attributes[2]
optionMap := make(map[string][]string, 0)
for _, option := range options {
if strings.HasPrefix(option, "post-up") {
tokens := strings.SplitAfterN(option, " ", 2)
if len(tokens) != 2 {
continue
}
if v, ok := optionMap["post-up"]; ok {
optionMap["post-up"] = append(v, tokens[1])
} else {
optionMap["post-up"] = []string{tokens[1]}
}
} else if strings.HasPrefix(option, "pre-down") {
tokens := strings.SplitAfterN(option, " ", 2)
if len(tokens) != 2 {
continue
}
if v, ok := optionMap["pre-down"]; ok {
optionMap["pre-down"] = append(v, tokens[1])
} else {
optionMap["pre-down"] = []string{tokens[1]}
}
} else {
tokens := strings.Fields(option)
optionMap[tokens[0]] = tokens[1:]
}
}
var conf configMethod
switch confMethod {
case "static":
config := configMethodStatic{
routes: make([]route, 0),
nameservers: make([]net.IP, 0),
}
if addresses, ok := optionMap["address"]; ok {
if len(addresses) == 1 {
config.address.IP = net.ParseIP(addresses[0])
}
}
if netmasks, ok := optionMap["netmask"]; ok {
if len(netmasks) == 1 {
config.address.Mask = net.IPMask(net.ParseIP(netmasks[0]).To4())
}
}
if config.address.IP == nil || config.address.Mask == nil {
return nil, fmt.Errorf("malformed static network config for '%s'", iface)
}
if gateways, ok := optionMap["gateway"]; ok {
if len(gateways) == 1 {
config.routes = append(config.routes, route{
destination: net.IPNet{
IP: net.IPv4(0, 0, 0, 0),
Mask: net.IPv4Mask(0, 0, 0, 0),
},
gateway: net.ParseIP(gateways[0]),
})
}
}
for _, nameserver := range optionMap["dns-nameservers"] {
config.nameservers = append(config.nameservers, net.ParseIP(nameserver))
}
for _, postup := range optionMap["post-up"] {
if strings.HasPrefix(postup, "route add") {
route := route{}
fields := strings.Fields(postup)
for i, field := range fields[:len(fields)-1] {
switch field {
case "-net":
route.destination.IP = net.ParseIP(fields[i+1])
case "netmask":
route.destination.Mask = net.IPMask(net.ParseIP(fields[i+1]).To4())
case "gw":
route.gateway = net.ParseIP(fields[i+1])
}
}
if route.destination.IP != nil && route.destination.Mask != nil && route.gateway != nil {
config.routes = append(config.routes, route)
}
}
}
conf = config
case "loopback":
conf = configMethodLoopback{}
case "manual":
conf = configMethodManual{}
case "dhcp":
conf = configMethodDHCP{}
default:
return nil, fmt.Errorf("invalid config method '%s'", confMethod)
}
if _, ok := optionMap["vlan_raw_device"]; ok {
return parseVLANStanza(iface, conf, attributes, optionMap)
}
if strings.Contains(iface, ".") {
return parseVLANStanza(iface, conf, attributes, optionMap)
}
if _, ok := optionMap["bond-slaves"]; ok {
return parseBondStanza(iface, conf, attributes, optionMap)
}
return parsePhysicalStanza(iface, conf, attributes, optionMap)
}
func parseBondStanza(iface string, conf configMethod, attributes []string, options map[string][]string) (*stanzaInterface, error) {
options["slaves"] = options["bond-slaves"]
return &stanzaInterface{name: iface, kind: interfaceBond, configMethod: conf, options: options}, nil
}
func parsePhysicalStanza(iface string, conf configMethod, attributes []string, options map[string][]string) (*stanzaInterface, error) {
return &stanzaInterface{name: iface, kind: interfacePhysical, configMethod: conf, options: options}, nil
}
func parseVLANStanza(iface string, conf configMethod, attributes []string, options map[string][]string) (*stanzaInterface, error) {
var id string
if strings.Contains(iface, ".") {
tokens := strings.Split(iface, ".")
id = tokens[len(tokens)-1]
} else if strings.HasPrefix(iface, "vlan") {
id = strings.TrimPrefix(iface, "vlan")
} else {
return nil, fmt.Errorf("malformed vlan name %s", iface)
}
if _, err := strconv.Atoi(id); err != nil {
return nil, fmt.Errorf("malformed vlan name %s", iface)
}
options["id"] = []string{id}
options["raw_device"] = options["vlan_raw_device"]
return &stanzaInterface{name: iface, kind: interfaceVLAN, configMethod: conf, options: options}, nil
}