func doServerWatch(kapi client.KeysAPI) {
watcher := kapi.Watcher(runningbase, &client.WatcherOptions{Recursive: true})
for true {
resp, err := watcher.Next(context.TODO())
if err != nil {
if _, ok := err.(*client.ClusterError); ok {
continue
}
log.Fatal(err)
}
fmt.Println(resp.Node.Key + " " + resp.Node.Value)
_, server := path.Split(resp.Node.Key)
switch resp.Action {
case "create":
fmt.Println(server + " has started heart beat")
case "compareAndSwap":
fmt.Println(server + " heart beat")
case "compareAndDelete":
fmt.Println(server + " has shut down correctly")
case "expire":
fmt.Println("*** " + server + " has missed heartbeat")
default:
fmt.Println("Didn't handle " + resp.Action)
}
}
}
func watch(kAPI etcd.KeysAPI, key string, stop chan struct{}) (res *etcd.Response) {
for res == nil {
select {
case <-stop:
log.Debugf("Gracefully closing etcd watch loop: key=%s", key)
return
default:
opts := &etcd.WatcherOptions{
AfterIndex: 0,
Recursive: true,
}
watcher := kAPI.Watcher(key, opts)
log.Debugf("Creating etcd watcher: %s", key)
var err error
res, err = watcher.Next(context.Background())
if err != nil {
log.Errorf("etcd watcher %v returned error: %v", key, err)
}
}
// Let's not slam the etcd server in the event that we know
// an unexpected error occurred.
time.Sleep(time.Second)
}
return
}
func watchKey(key string, blockControlChan chan blocker.ControlMsg, kapi client.KeysAPI) {
watcher := kapi.Watcher(key, &client.WatcherOptions{Recursive: true})
for {
response, _ := watcher.Next(context.Background())
switch response.Action {
case "create":
// counter: sync.set
handleKey(*response.Node, blockControlChan, true)
log.Println("[sync]\tetcd: create: " + response.Node.Key)
case "set":
// counter: sync.set
handleKey(*response.Node, blockControlChan, true)
log.Println("[sync]\tetcd: create: " + response.Node.Key)
case "delete":
// counter: sync.delete
handleKey(*response.Node, blockControlChan, false)
log.Println("[sync]\tetcd: delete: " + response.Node.Key)
case "expire":
// counter: sync.expire
handleKey(*response.Node, blockControlChan, false)
log.Println("[sync]\tetcd: expired: " + response.Node.Key)
}
}
}
// etcdWatch calls etcd's Watch function, and handles any errors. Meant to be called
// as a goroutine.
func (w *etcdWatcher) etcdWatch(ctx context.Context, client etcd.KeysAPI, key string, resourceVersion uint64) {
defer util.HandleCrash()
defer close(w.etcdError)
defer close(w.etcdIncoming)
if resourceVersion == 0 {
latest, err := etcdGetInitialWatchState(ctx, client, key, w.list, w.etcdIncoming)
if err != nil {
w.etcdError <- err
return
}
resourceVersion = latest
}
opts := etcd.WatcherOptions{
Recursive: w.list,
AfterIndex: resourceVersion,
}
watcher := client.Watcher(key, &opts)
w.stopLock.Lock()
w.ctx, w.cancel = context.WithCancel(ctx)
w.stopLock.Unlock()
for {
resp, err := watcher.Next(w.ctx)
if err != nil {
w.etcdError <- err
return
}
w.etcdIncoming <- resp
}
}
// non-blocking
func mustWatchServiceDefs(ctx context.Context, client etcd.KeysAPI, basepath *string, changed chan<- bool) {
wOpts := &etcd.WatcherOptions{Recursive: true}
watcher := client.Watcher(*basepath, wOpts)
watchOperation := func() error {
resp, err := watcher.Next(ctx)
if err != nil {
switch v := err.(type) {
case etcd.Error:
if v.Code == etcd.ErrorCodeEventIndexCleared {
watcher = client.Watcher(*basepath, wOpts)
log.WithFields(log.Fields{
"basepath": *basepath,
"code": v.Code,
"cause": v.Cause,
"index": v.Index,
"message": v.Message,
}).Warn("refreshed watcher")
return nil
}
default:
if err.Error() == "unexpected end of JSON input" {
log.WithField("error", err).Warn("probably a connection timeout. are we in etcd 0.4.x?")
return nil
} else {
return err
}
}
}
if resp.Action != "get" {
changed <- true
}
return nil
}
notify := func(err error, dur time.Duration) {
log.WithFields(log.Fields{
"dur": dur,
"error": err,
"service_path": *basepath,
}).Error("service definition watch failed. backing off.")
}
go func() {
for {
err := backoff.RetryNotify(watchOperation, backoff.NewExponentialBackOff(), notify)
if err != nil {
log.WithFields(log.Fields{
"error": err,
"service_path": *basepath,
}).Fatal("unable to recover communication with etcd, watch abandoned")
}
}
}()
}
// etcdWatch calls etcd's Watch function, and handles any errors. Meant to be called
// as a goroutine.
func (w *etcdWatcher) etcdWatch(ctx context.Context, client etcd.KeysAPI, key string, resourceVersion uint64) {
defer utilruntime.HandleCrash()
defer close(w.etcdError)
defer close(w.etcdIncoming)
// All calls to etcd are coming from this function - once it is finished
// no other call to etcd should be generated by this watcher.
done := func() {}
// We need to be prepared, that Stop() can be called at any time.
// It can potentially also be called, even before this function is called.
// If that is the case, we simply skip all the code here.
// See #18928 for more details.
var watcher etcd.Watcher
returned := func() bool {
w.stopLock.Lock()
defer w.stopLock.Unlock()
if w.stopped {
// Watcher has already been stopped - don't event initiate it here.
return true
}
w.wg.Add(1)
done = w.wg.Done
// Perform initialization of watcher under lock - we want to avoid situation when
// Stop() is called in the meantime (which in tests can cause etcd termination and
// strange behavior here).
if resourceVersion == 0 {
latest, err := etcdGetInitialWatchState(ctx, client, key, w.list, w.quorum, w.etcdIncoming)
if err != nil {
w.etcdError <- err
return true
}
resourceVersion = latest
}
opts := etcd.WatcherOptions{
Recursive: w.list,
AfterIndex: resourceVersion,
}
watcher = client.Watcher(key, &opts)
w.ctx, w.cancel = context.WithCancel(ctx)
return false
}()
defer done()
if returned {
return
}
for {
resp, err := watcher.Next(w.ctx)
if err != nil {
w.etcdError <- err
return
}
w.etcdIncoming <- resp
}
}
func generateConfigWatcher(kapi client.KeysAPI, resp *client.Response) (*client.Response, error) {
watcher := kapi.Watcher(*etcdPrefix, &client.WatcherOptions{Recursive: true, AfterIndex: resp.Index})
ctx := context.Background()
resp, err := watcher.Next(ctx)
if err != nil {
return resp, err
}
return generateConfig(kapi)
}
func watch(kapi client.KeysAPI, key string, fn callback) {
watcher := kapi.Watcher(key, nil)
for {
resp, err := watcher.Next(context.TODO())
if err != nil {
log.Printf("!! ERR: %v\n", err)
break
}
if err := fn(resp.Node); err != nil {
// we got an outdated node. we should trigger a get
// to ensure we get the latest value.
get(kapi, key, fn)
}
}
}
func watchService(ctx *done.Context, api client.KeysAPI, space *Namespace) {
dir := watchDir(space.name)
opts := &client.WatcherOptions{Recursive: true}
watcher := api.Watcher(dir, opts)
log.Infof("watch %s start", dir)
for {
update(watcher, space)
select {
case <-ctx.Done():
log.Infof("watch %s done", dir)
ctx.OK()
return
default:
continue
}
}
}
func waitForEtcd(api client.KeysAPI, c *cli.Context) error {
_, err := api.Get(context.Background(), c.String("key-watch"), nil)
if err != nil {
// key is not present have to watch it
if m, _ := regexp.MatchString("100", err.Error()); m {
w := api.Watcher(c.String("key-watch"), &client.WatcherOptions{AfterIndex: 0, Recursive: false})
_, err := w.Next(context.Background())
if err != nil {
return err
}
return nil
} else {
return err
}
}
// key is already present
return nil
}
func doServer(kapi client.KeysAPI) {
var key = configbase + *servername
var settings map[string]string
settings = make(map[string]string)
resp, err := kapi.Get(context.TODO(), key, &client.GetOptions{Recursive: true})
if err != nil {
log.Fatal(err)
}
for _, node := range resp.Node.Nodes {
_, setting := path.Split(node.Key)
settings[setting] = node.Value
}
fmt.Println(settings)
watcher := kapi.Watcher(key, &client.WatcherOptions{Recursive: true})
for true {
resp, err := watcher.Next(context.TODO())
if err != nil {
if _, ok := err.(*client.ClusterError); ok {
continue
}
log.Fatal(err)
}
switch resp.Action {
case "set":
_, setting := path.Split(resp.Node.Key)
settings[setting] = resp.Node.Value
case "delete", "expire":
_, setting := path.Split(resp.Node.Key)
delete(settings, setting)
}
fmt.Println(settings)
}
}
// watchCommandFunc executes the "watch" command.
func watchCommandFunc(c *cli.Context, ki client.KeysAPI) {
if len(c.Args()) == 0 {
handleError(ExitBadArgs, errors.New("key required"))
}
key := c.Args()[0]
recursive := c.Bool("recursive")
forever := c.Bool("forever")
index := 0
if c.Int("after-index") != 0 {
index = c.Int("after-index") + 1
}
stop := false
w := ki.Watcher(key, &client.WatcherOptions{AfterIndex: uint64(index), Recursive: recursive})
sigch := make(chan os.Signal, 1)
signal.Notify(sigch, os.Interrupt)
go func() {
<-sigch
os.Exit(0)
}()
for !stop {
resp, err := w.Next(context.TODO())
if err != nil {
handleError(ExitServerError, err)
}
if resp.Node.Dir {
continue
}
if recursive {
fmt.Printf("[%s] %s\n", resp.Action, resp.Node.Key)
}
printResponseKey(resp, c.GlobalString("output"))
if !forever {
stop = true
}
}
}
func OnUpdateIFace(etcdCli etcd.Client, key string, fn func(val interface{})) {
var kapi etcd.KeysAPI
var ctx context.Context
kapi = etcd.NewKeysAPI(etcdCli)
ctx = context.Background()
go func(w etcd.Watcher) {
var err error
var resp *etcd.Response
for {
resp, err = w.Next(ctx)
if err == nil {
Goose.Updater.Logf(3, "Updating config variable %s = %s", key, resp.Node.Value)
fn(resp.Node.Value)
} else {
Goose.Updater.Logf(1, "Error updating config variable %s (%s)", key, err)
}
}
}(kapi.Watcher("/"+key, nil))
}
func newNotifier(kapi client.KeysAPI, path string) notifier {
w := notifier{make(chan struct{}, 1)}
go func() {
for {
watcher := kapi.Watcher(path, &client.WatcherOptions{Recursive: true})
var err error
var response *client.Response
for err == nil {
response, err = watcher.Next(context.Background())
logResponse(response)
select {
case w.ch <- struct{}{}:
log.Println("received event from watcher, sent change message on notifier channel.")
default:
log.Println("received event from watcher, not sending message on notifier channel, buffer full and no-one listening.")
}
}
if err == context.Canceled {
log.Println("context cancelled error")
} else if err == context.DeadlineExceeded {
log.Println("deadline exceeded error")
} else if cerr, ok := err.(*client.ClusterError); ok {
log.Printf("cluster error. Details: %v\n", cerr.Detail())
} else {
// bad cluster endpoints, which are not etcd servers
log.Println(err.Error())
}
log.Println("sleeping for 15s before rebuilding config due to error")
time.Sleep(15 * time.Second)
}
}()
return w
}
func OnUpdateTree(etcdCli etcd.Client, key string, fn func(key string, val interface{}, action string)) {
var kapi etcd.KeysAPI
var ctx context.Context
kapi = etcd.NewKeysAPI(etcdCli)
ctx = context.Background()
go func(w etcd.Watcher) {
var err error
var resp *etcd.Response
for {
resp, err = w.Next(ctx)
if err == nil {
Goose.Updater.Logf(3, "Updating (%s) config variable %s = %s", resp.Action, key, resp.Node.Value)
fn(resp.Node.Key, resp.Node.Value, resp.Action)
} else {
Goose.Updater.Logf(1, "Error updating config variable %s (%s)", key, err)
}
}
}(kapi.Watcher("/"+key, &etcd.WatcherOptions{Recursive: true}))
}
func newWatcher(kapi client.KeysAPI, path string, socksProxy string, etcdPeers []string) watcher {
w := watcher{make(chan struct{}, 1)}
go func() {
watcher := kapi.Watcher(path, &client.WatcherOptions{Recursive: true})
for {
_, err := watcher.Next(context.Background())
if err != nil {
log.Printf("watch failed %v, sleeping for 1s\n", err.Error())
time.Sleep(1 * time.Second)
} else {
select {
case w.ch <- struct{}{}:
default:
}
}
}
}()
return w
}
// execWatchCommandFunc executes the "exec-watch" command.
func execWatchCommandFunc(c *cli.Context, ki client.KeysAPI) {
args := c.Args()
argslen := len(args)
if argslen < 2 {
handleError(ExitBadArgs, errors.New("key and command to exec required"))
}
var (
key string
cmdArgs []string
)
foundSep := false
for i := range args {
if args[i] == "--" && i != 0 {
foundSep = true
break
}
}
if foundSep {
key = args[0]
cmdArgs = args[2:]
} else {
// If no flag is parsed, the order of key and cmdArgs will be switched and
// args will not contain `--`.
key = args[argslen-1]
cmdArgs = args[:argslen-1]
}
index := 0
if c.Int("after-index") != 0 {
index = c.Int("after-index") + 1
}
recursive := c.Bool("recursive")
sigch := make(chan os.Signal, 1)
signal.Notify(sigch, os.Interrupt)
go func() {
<-sigch
os.Exit(0)
}()
w := ki.Watcher(key, &client.WatcherOptions{AfterIndex: uint64(index), Recursive: recursive})
for {
resp, err := w.Next(context.TODO())
if err != nil {
handleError(ExitServerError, err)
}
if resp.Node.Dir {
fmt.Fprintf(os.Stderr, "Ignored dir %s change", resp.Node.Key)
continue
}
cmd := exec.Command(cmdArgs[0], cmdArgs[1:]...)
cmd.Env = environResponse(resp, os.Environ())
stdout, err := cmd.StdoutPipe()
if err != nil {
fmt.Fprintf(os.Stderr, err.Error())
os.Exit(1)
}
stderr, err := cmd.StderrPipe()
if err != nil {
fmt.Fprintf(os.Stderr, err.Error())
os.Exit(1)
}
go func() {
err := cmd.Start()
if err != nil {
fmt.Fprintf(os.Stderr, err.Error())
os.Exit(1)
}
go io.Copy(os.Stdout, stdout)
go io.Copy(os.Stderr, stderr)
cmd.Wait()
}()
}
}
func main() {
flag.Parse()
if config.Version {
fmt.Printf("skydns server version: %s\n", server.Version)
os.Exit(0)
}
machines := strings.Split(machine, ",")
var clientptr *etcdv3.Client
var err error
var clientv3 etcdv3.Client
var clientv2 etcd.KeysAPI
if config.Etcd3 {
clientptr, err = newEtcdV3Client(machines, tlspem, tlskey, cacert)
clientv3 = *clientptr
} else {
clientv2, err = newEtcdV2Client(machines, tlspem, tlskey, cacert, username, password)
}
if err != nil {
panic(err)
}
if nameserver != "" {
for _, hostPort := range strings.Split(nameserver, ",") {
if err := validateHostPort(hostPort); err != nil {
log.Fatalf("skydns: nameserver is invalid: %s", err)
}
config.Nameservers = append(config.Nameservers, hostPort)
}
}
if err := validateHostPort(config.DnsAddr); err != nil {
log.Fatalf("skydns: addr is invalid: %s", err)
}
if config.Etcd3 {
if err := loadEtcdV3Config(clientv3, config); err != nil {
log.Fatalf("skydns: %s", err)
}
} else {
if err := loadEtcdV2Config(clientv2, config); err != nil {
log.Fatalf("skydns: %s", err)
}
}
if err := server.SetDefaults(config); err != nil {
log.Fatalf("skydns: defaults could not be set from /etc/resolv.conf: %v", err)
}
if config.Local != "" {
config.Local = dns.Fqdn(config.Local)
}
var backend server.Backend
if config.Etcd3 {
backend = backendetcdv3.NewBackendv3(clientv3, ctx, &backendetcdv3.Config{
Ttl: config.Ttl,
Priority: config.Priority,
})
} else {
backend = backendetcd.NewBackend(clientv2, ctx, &backendetcd.Config{
Ttl: config.Ttl,
Priority: config.Priority,
})
}
s := server.New(backend, config)
if stub {
s.UpdateStubZones()
go func() {
duration := 1 * time.Second
if config.Etcd3 {
var watcher etcdv3.WatchChan
watcher = clientv3.Watch(ctx, msg.Path(config.Domain)+"/dns/stub/", etcdv3.WithPrefix())
for wresp := range watcher {
if wresp.Err() != nil {
log.Printf("skydns: stubzone update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9)))
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
} else {
s.UpdateStubZones()
log.Printf("skydns: stubzone update")
duration = 1 * time.Second //reset
}
}
} else {
var watcher etcd.Watcher
watcher = clientv2.Watcher(msg.Path(config.Domain)+"/dns/stub/", &etcd.WatcherOptions{AfterIndex: 0, Recursive: true})
for {
_, err := watcher.Next(ctx)
if err != nil {
//
log.Printf("skydns: stubzone update failed, sleeping %s + ~3s", duration)
time.Sleep(duration + (time.Duration(rand.Float32() * 3e9))) // Add some random.
duration *= 2
if duration > 32*time.Second {
duration = 32 * time.Second
}
} else {
s.UpdateStubZones()
log.Printf("skydns: stubzone update")
duration = 1 * time.Second // reset
}
}
}
}()
}
if err := metrics.Metrics(); err != nil {
log.Fatalf("skydns: %s", err)
} else {
log.Printf("skydns: metrics enabled on :%s%s", metrics.Port, metrics.Path)
}
if err := s.Run(); err != nil {
log.Fatalf("skydns: %s", err)
}
}
