func (sb *sandbox) updateDNS(ipv6Enabled bool) error {
var (
currHash string
hashFile = sb.config.resolvConfHashFile
)
// This is for the host mode networking
if sb.config.originResolvConfPath != "" {
return nil
}
if len(sb.config.dnsList) > 0 || len(sb.config.dnsSearchList) > 0 || len(sb.config.dnsOptionsList) > 0 {
return nil
}
currRC, err := resolvconf.GetSpecific(sb.config.resolvConfPath)
if err != nil {
if !os.IsNotExist(err) {
return err
}
} else {
h, err := ioutil.ReadFile(hashFile)
if err != nil {
if !os.IsNotExist(err) {
return err
}
} else {
currHash = string(h)
}
}
if currHash != "" && currHash != currRC.Hash {
// Seems the user has changed the container resolv.conf since the last time
// we checked so return without doing anything.
//log.Infof("Skipping update of resolv.conf file with ipv6Enabled: %t because file was touched by user", ipv6Enabled)
return nil
}
// replace any localhost/127.* and remove IPv6 nameservers if IPv6 disabled.
newRC, err := resolvconf.FilterResolvDNS(currRC.Content, ipv6Enabled)
if err != nil {
return err
}
err = ioutil.WriteFile(sb.config.resolvConfPath, newRC.Content, 0644)
if err != nil {
return err
}
// write the new hash in a temp file and rename it to make the update atomic
dir := path.Dir(sb.config.resolvConfPath)
tmpHashFile, err := ioutil.TempFile(dir, "hash")
if err != nil {
return err
}
if err = ioutil.WriteFile(tmpHashFile.Name(), []byte(newRC.Hash), filePerm); err != nil {
return err
}
return os.Rename(tmpHashFile.Name(), hashFile)
}
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
}
} else {
// 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
}
func (sb *sandbox) updateDNS(ipv6Enabled bool) error {
var (
currHash string
hashFile = sb.config.resolvConfHashFile
)
if len(sb.config.dnsList) > 0 || len(sb.config.dnsSearchList) > 0 || len(sb.config.dnsOptionsList) > 0 {
return nil
}
currRC, err := resolvconf.GetSpecific(sb.config.resolvConfPath)
if err != nil {
if !os.IsNotExist(err) {
return err
}
} else {
h, err := ioutil.ReadFile(hashFile)
if err != nil {
if !os.IsNotExist(err) {
return err
}
} else {
currHash = string(h)
}
}
if currHash != "" && currHash != currRC.Hash {
// Seems the user has changed the container resolv.conf since the last time
// we checked so return without doing anything.
log.Infof("Skipping update of resolv.conf file with ipv6Enabled: %t because file was touched by user", ipv6Enabled)
return nil
}
// replace any localhost/127.* and remove IPv6 nameservers if IPv6 disabled.
newRC, err := resolvconf.FilterResolvDNS(currRC.Content, ipv6Enabled)
if err != nil {
return err
}
// for atomic updates to these files, use temporary files with os.Rename:
dir := path.Dir(sb.config.resolvConfPath)
tmpHashFile, err := ioutil.TempFile(dir, "hash")
if err != nil {
return err
}
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
}
// write the updates to the temp files
if err = ioutil.WriteFile(tmpHashFile.Name(), []byte(newRC.Hash), filePerm); err != nil {
return err
}
if err = ioutil.WriteFile(tmpResolvFile.Name(), newRC.Content, filePerm); err != nil {
return err
}
// rename the temp files for atomic replace
if err = os.Rename(tmpHashFile.Name(), hashFile); 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
}
func (sb *sandbox) updateDNS(ipv6Enabled bool) error {
var oldHash []byte
hashFile := sb.config.resolvConfHashFile
resolvConf, err := ioutil.ReadFile(sb.config.resolvConfPath)
if err != nil {
if !os.IsNotExist(err) {
return err
}
} else {
oldHash, err = ioutil.ReadFile(hashFile)
if err != nil {
if !os.IsNotExist(err) {
return err
}
oldHash = []byte{}
}
}
curHash, err := ioutils.HashData(bytes.NewReader(resolvConf))
if err != nil {
return err
}
if string(oldHash) != "" && curHash != string(oldHash) {
// Seems the user has changed the container resolv.conf since the last time
// we checked so return without doing anything.
log.Infof("Skipping update of resolv.conf file with ipv6Enabled: %t because file was touched by user", ipv6Enabled)
return nil
}
// replace any localhost/127.* and remove IPv6 nameservers if IPv6 disabled.
resolvConf, _ = resolvconf.FilterResolvDNS(resolvConf, ipv6Enabled)
newHash, err := ioutils.HashData(bytes.NewReader(resolvConf))
if err != nil {
return err
}
// for atomic updates to these files, use temporary files with os.Rename:
dir := path.Dir(sb.config.resolvConfPath)
tmpHashFile, err := ioutil.TempFile(dir, "hash")
if err != nil {
return err
}
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
}
// write the updates to the temp files
if err = ioutil.WriteFile(tmpHashFile.Name(), []byte(newHash), filePerm); err != nil {
return err
}
if err = ioutil.WriteFile(tmpResolvFile.Name(), resolvConf, filePerm); err != nil {
return err
}
// rename the temp files for atomic replace
if err = os.Rename(tmpHashFile.Name(), hashFile); err != nil {
return err
}
return os.Rename(tmpResolvFile.Name(), sb.config.resolvConfPath)
}
func (ep *endpoint) updateDNS(resolvConf []byte) error {
ep.Lock()
container := ep.container
network := ep.network
ep.Unlock()
if container == nil {
return ErrNoContainer{}
}
oldHash := []byte{}
hashFile := container.config.resolvConfPath + ".hash"
resolvBytes, err := ioutil.ReadFile(container.config.resolvConfPath)
if err != nil {
if !os.IsNotExist(err) {
return err
}
} else {
oldHash, err = ioutil.ReadFile(hashFile)
if err != nil {
if !os.IsNotExist(err) {
return err
}
oldHash = []byte{}
}
}
curHash, err := ioutils.HashData(bytes.NewReader(resolvBytes))
if err != nil {
return err
}
if string(oldHash) != "" && curHash != string(oldHash) {
// Seems the user has changed the container resolv.conf since the last time
// we checked so return without doing anything.
return nil
}
// replace any localhost/127.* and remove IPv6 nameservers if IPv6 disabled.
resolvConf, _ = resolvconf.FilterResolvDNS(resolvConf, network.enableIPv6)
newHash, err := ioutils.HashData(bytes.NewReader(resolvConf))
if err != nil {
return err
}
// for atomic updates to these files, use temporary files with os.Rename:
dir := path.Dir(container.config.resolvConfPath)
tmpHashFile, err := ioutil.TempFile(dir, "hash")
if err != nil {
return err
}
tmpResolvFile, err := ioutil.TempFile(dir, "resolv")
if err != nil {
return err
}
// Change the perms to 0644 since ioutil.TempFile creates it by default as 0600
if err := os.Chmod(tmpResolvFile.Name(), 0644); err != nil {
return err
}
// write the updates to the temp files
if err = ioutil.WriteFile(tmpHashFile.Name(), []byte(newHash), 0644); err != nil {
return err
}
if err = ioutil.WriteFile(tmpResolvFile.Name(), resolvConf, 0644); err != nil {
return err
}
// rename the temp files for atomic replace
if err = os.Rename(tmpHashFile.Name(), hashFile); err != nil {
return err
}
return os.Rename(tmpResolvFile.Name(), container.config.resolvConfPath)
}