func ExampleKV_delete() {
cli, err := clientv3.New(clientv3.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
})
if err != nil {
log.Fatal(err)
}
defer cli.Close()
ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
defer cancel()
// count keys about to be deleted
gresp, err := cli.Get(ctx, "key", clientv3.WithPrefix())
if err != nil {
log.Fatal(err)
}
// delete the keys
dresp, err := cli.Delete(ctx, "key", clientv3.WithPrefix())
if err != nil {
log.Fatal(err)
}
fmt.Println("Deleted all keys:", int64(len(gresp.Kvs)) == dresp.Deleted)
// Output:
// Deleted all keys: true
}
func TestWatch(t *testing.T) {
sync := newSync(t)
sync.etcdClient.Delete(context.Background(), "/", etcd.WithPrefix())
path := "/path/to/watch"
responseChan := make(chan *gohan_sync.Event)
stopChan := make(chan bool)
sync.etcdClient.Put(context.Background(), path+"/existing", `{"existing": true}`)
go func() {
err := sync.Watch(path, responseChan, stopChan)
if err != nil {
t.Errorf("failed to watch")
}
}()
resp := <-responseChan
if resp.Action != "get" || resp.Key != path+"/existing" || resp.Data["existing"].(bool) != true {
t.Errorf("mismatch response: %+v", resp)
}
sync.etcdClient.Put(context.Background(), path+"/new", `{"existing": false}`)
resp = <-responseChan
if resp.Action != "set" || resp.Key != path+"/new" || resp.Data["existing"].(bool) != false {
t.Errorf("mismatch response: %+v", resp)
}
sync.etcdClient.Delete(context.Background(), path+"/existing")
resp = <-responseChan
if resp.Action != "delete" || resp.Key != path+"/existing" || len(resp.Data) != 0 {
t.Errorf("mismatch response: %+v", resp)
}
}
func (e *etcdv3Registry) ListServices() ([]*registry.Service, error) {
var services []*registry.Service
nameSet := make(map[string]struct{})
ctx, cancel := context.WithTimeout(context.Background(), e.options.Timeout)
defer cancel()
rsp, err := e.client.Get(ctx, prefix, clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortDescend))
if err != nil {
return nil, err
}
if len(rsp.Kvs) == 0 {
return []*registry.Service{}, nil
}
for _, n := range rsp.Kvs {
if sn := decode(n.Value); sn != nil {
nameSet[sn.Name] = struct{}{}
}
}
for k := range nameSet {
service := ®istry.Service{}
service.Name = k
services = append(services, service)
}
return services, nil
}
// Enter waits for "count" processes to enter the barrier then returns
func (b *DoubleBarrier) Enter() error {
ek, err := NewUniqueEphemeralKey(b.client, b.key+"/waiters")
if err != nil {
return err
}
b.myKey = ek
resp, err := b.client.Get(b.ctx, b.key+"/waiters", clientv3.WithPrefix())
if err != nil {
return err
}
if len(resp.Kvs) > b.count {
return ErrTooManyClients
}
if len(resp.Kvs) == b.count {
// unblock waiters
_, err = b.client.Put(b.ctx, b.key+"/ready", "")
return err
}
_, err = WaitEvents(
b.client,
b.key+"/ready",
ek.Revision(),
[]storagepb.Event_EventType{storagepb.PUT})
return err
}
// Leave waits for "count" processes to leave the barrier then returns
func (b *DoubleBarrier) Leave() error {
resp, err := b.client.Get(b.ctx, b.key+"/waiters", clientv3.WithPrefix())
if err != nil {
return err
}
if len(resp.Kvs) == 0 {
return nil
}
lowest, highest := resp.Kvs[0], resp.Kvs[0]
for _, k := range resp.Kvs {
if k.ModRevision < lowest.ModRevision {
lowest = k
}
if k.ModRevision > highest.ModRevision {
highest = k
}
}
isLowest := string(lowest.Key) == b.myKey.Key()
if len(resp.Kvs) == 1 {
// this is the only node in the barrier; finish up
if _, err = b.client.Delete(b.ctx, b.key+"/ready"); err != nil {
return err
}
return b.myKey.Delete()
}
// this ensures that if a process fails, the ephemeral lease will be
// revoked, its barrier key is removed, and the barrier can resume
// lowest process in node => wait on highest process
if isLowest {
_, err = WaitEvents(
b.client,
string(highest.Key),
highest.ModRevision,
[]storagepb.Event_EventType{storagepb.DELETE})
if err != nil {
return err
}
return b.Leave()
}
// delete self and wait on lowest process
if err := b.myKey.Delete(); err != nil {
return err
}
key := string(lowest.Key)
_, err = WaitEvents(
b.client,
key,
lowest.ModRevision,
[]storagepb.Event_EventType{storagepb.DELETE})
if err != nil {
return err
}
return b.Leave()
}
func WaitPrefixEvents(c *clientv3.Client, prefix string, rev int64, evs []mvccpb.Event_EventType) (*clientv3.Event, error) {
wc := c.Watch(context.Background(), prefix, clientv3.WithPrefix(), clientv3.WithRev(rev))
if wc == nil {
return nil, ErrNoWatcher
}
return waitEvents(wc, evs), nil
}
// startWatching does:
// - get current objects if initialRev=0; set initialRev to current rev
// - watch on given key and send events to process.
func (wc *watchChan) startWatching(watchClosedCh chan struct{}) {
if wc.initialRev == 0 {
if err := wc.sync(); err != nil {
glog.Errorf("failed to sync with latest state: %v", err)
wc.sendError(err)
return
}
}
opts := []clientv3.OpOption{clientv3.WithRev(wc.initialRev + 1), clientv3.WithPrevKV()}
if wc.recursive {
opts = append(opts, clientv3.WithPrefix())
}
wch := wc.watcher.client.Watch(wc.ctx, wc.key, opts...)
for wres := range wch {
if wres.Err() != nil {
err := wres.Err()
// If there is an error on server (e.g. compaction), the channel will return it before closed.
glog.Errorf("watch chan error: %v", err)
wc.sendError(err)
return
}
for _, e := range wres.Events {
wc.sendEvent(parseEvent(e))
}
}
// When we come to this point, it's only possible that client side ends the watch.
// e.g. cancel the context, close the client.
// If this watch chan is broken and context isn't cancelled, other goroutines will still hang.
// We should notify the main thread that this goroutine has exited.
close(watchClosedCh)
}
// watchCommandFunc executes the "watch" command.
func watchCommandFunc(cmd *cobra.Command, args []string) {
if watchInteractive {
watchInteractiveFunc(cmd, args)
return
}
if len(args) < 1 || len(args) > 2 {
ExitWithError(ExitBadArgs, fmt.Errorf("watch in non-interactive mode requires one or two arguments as key or prefix, with range end"))
}
opts := []clientv3.OpOption{clientv3.WithRev(watchRev)}
key := args[0]
if len(args) == 2 {
if watchPrefix {
ExitWithError(ExitBadArgs, fmt.Errorf("`range_end` and `--prefix` cannot be set at the same time, choose one"))
}
opts = append(opts, clientv3.WithRange(args[1]))
}
if watchPrefix {
opts = append(opts, clientv3.WithPrefix())
}
c := mustClientFromCmd(cmd)
wc := c.Watch(context.TODO(), key, opts...)
printWatchCh(wc)
err := c.Close()
if err == nil {
ExitWithError(ExitInterrupted, fmt.Errorf("watch is canceled by the server"))
}
ExitWithError(ExitBadConnection, err)
}
func getDelOp(cmd *cobra.Command, args []string) (string, []clientv3.OpOption) {
if len(args) == 0 || len(args) > 2 {
ExitWithError(ExitBadArgs, fmt.Errorf("del command needs one argument as key and an optional argument as range_end."))
}
if delPrefix && delFromKey {
ExitWithError(ExitBadArgs, fmt.Errorf("`--prefix` and `--from-key` cannot be set at the same time, choose one."))
}
opts := []clientv3.OpOption{}
key := args[0]
if len(args) > 1 {
if delPrefix || delFromKey {
ExitWithError(ExitBadArgs, fmt.Errorf("too many arguments, only accept one argument when `--prefix` or `--from-key` is set."))
}
opts = append(opts, clientv3.WithRange(args[1]))
}
if delPrefix {
opts = append(opts, clientv3.WithPrefix())
}
if delPrevKV {
opts = append(opts, clientv3.WithPrevKV())
}
if delFromKey {
if len(key) == 0 {
key = "\x00"
}
opts = append(opts, clientv3.WithFromKey())
}
return key, opts
}
func (n *ng) GetSnapshot() (*engine.Snapshot, error) {
response, err := n.client.Get(n.context, n.etcdKey, etcd.WithPrefix(), etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
if err != nil {
return nil, err
}
s := &engine.Snapshot{Index: uint64(response.Header.Revision)}
s.FrontendSpecs, err = n.parseFrontends(filterByPrefix(response.Kvs, n.etcdKey+"/frontends"))
if err != nil {
return nil, err
}
s.BackendSpecs, err = n.parseBackends(filterByPrefix(response.Kvs, n.etcdKey+"/backends"))
if err != nil {
return nil, err
}
s.Hosts, err = n.parseHosts(filterByPrefix(response.Kvs, n.etcdKey+"/hosts"))
if err != nil {
return nil, err
}
s.Listeners, err = n.parseListeners(filterByPrefix(response.Kvs, n.etcdKey+"/listeners"))
if err != nil {
return nil, err
}
return s, nil
}
func ExampleKV_getSortedPrefix() {
cli, err := clientv3.New(clientv3.Config{
Endpoints: endpoints,
DialTimeout: dialTimeout,
})
if err != nil {
log.Fatal(err)
}
defer cli.Close()
kvc := clientv3.NewKV(cli)
for i := range make([]int, 3) {
ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
_, err = kvc.Put(ctx, fmt.Sprintf("key_%d", i), "value")
cancel()
if err != nil {
log.Fatal(err)
}
}
ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
resp, err := kvc.Get(ctx, "key", clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortDescend))
cancel()
if err != nil {
log.Fatal(err)
}
for _, ev := range resp.Kvs {
fmt.Printf("%s : %s\n", ev.Key, ev.Value)
}
// key_2 : value
// key_1 : value
// key_0 : value
}
func (e *Election) observe(ctx context.Context, ch chan<- v3.GetResponse) {
client := e.session.Client()
defer close(ch)
for {
resp, err := client.Get(ctx, e.keyPrefix, v3.WithFirstCreate()...)
if err != nil {
return
}
var kv *mvccpb.KeyValue
cctx, cancel := context.WithCancel(ctx)
if len(resp.Kvs) == 0 {
// wait for first key put on prefix
opts := []v3.OpOption{v3.WithRev(resp.Header.Revision), v3.WithPrefix()}
wch := client.Watch(cctx, e.keyPrefix, opts...)
for kv == nil {
wr, ok := <-wch
if !ok || wr.Err() != nil {
cancel()
return
}
// only accept PUTs; a DELETE will make observe() spin
for _, ev := range wr.Events {
if ev.Type == mvccpb.PUT {
kv = ev.Kv
break
}
}
}
} else {
kv = resp.Kvs[0]
}
wch := client.Watch(cctx, string(kv.Key), v3.WithRev(kv.ModRevision))
keyDeleted := false
for !keyDeleted {
wr, ok := <-wch
if !ok {
return
}
for _, ev := range wr.Events {
if ev.Type == mvccpb.DELETE {
keyDeleted = true
break
}
resp.Header = &wr.Header
resp.Kvs = []*mvccpb.KeyValue{ev.Kv}
select {
case ch <- *resp:
case <-cctx.Done():
return
}
}
}
cancel()
}
}
// watchCommandFunc executes the "watch" command.
func watchCommandFunc(cmd *cobra.Command, args []string) {
if watchInteractive {
watchInteractiveFunc(cmd, args)
return
}
if len(args) != 1 {
ExitWithError(ExitBadArgs, fmt.Errorf("watch in non-interactive mode requires an argument as key or prefix"))
}
c := mustClientFromCmd(cmd)
w := clientv3.NewWatcher(c)
opts := []clientv3.OpOption{clientv3.WithRev(watchRev)}
if watchPrefix {
opts = append(opts, clientv3.WithPrefix())
}
wc := w.Watch(context.TODO(), args[0], opts...)
printWatchCh(wc)
err := w.Close()
if err == nil {
ExitWithError(ExitInterrupted, fmt.Errorf("watch is canceled by the server"))
}
ExitWithError(ExitBadConnection, err)
}
func TestNonEmptyUpdate(t *testing.T) {
sync := newSync(t)
sync.etcdClient.Delete(context.Background(), "/", etcd.WithPrefix())
path := "/path/to/somewhere"
data := "blabla"
err := sync.Update(path, data)
if err != nil {
t.Errorf("unexpected error")
}
node, err := sync.Fetch(path)
if err != nil {
t.Errorf("unexpected error")
}
if node.Key != path || node.Value != data || len(node.Children) != 0 {
t.Errorf("unexpected node: %+v", node)
}
err = sync.Delete(path)
if err != nil {
t.Errorf("unexpected error")
}
node, err = sync.Fetch(path)
if err == nil {
t.Errorf("unexpected non error")
}
}
// Lock locks the mutex with a cancellable context. If the context is cancelled
// while trying to acquire the lock, the mutex tries to clean its stale lock entry.
func (m *Mutex) Lock(ctx context.Context) error {
s, serr := NewSession(m.client)
if serr != nil {
return serr
}
m.myKey = fmt.Sprintf("%s/%x", m.pfx, s.Lease())
cmp := v3.Compare(v3.CreateRevision(m.myKey), "=", 0)
// put self in lock waiters via myKey; oldest waiter holds lock
put := v3.OpPut(m.myKey, "", v3.WithLease(s.Lease()))
// reuse key in case this session already holds the lock
get := v3.OpGet(m.myKey)
resp, err := m.client.Txn(ctx).If(cmp).Then(put).Else(get).Commit()
if err != nil {
return err
}
m.myRev = resp.Header.Revision
if !resp.Succeeded {
m.myRev = resp.Responses[0].GetResponseRange().Kvs[0].CreateRevision
}
// wait for deletion revisions prior to myKey
err = waitDeletes(ctx, m.client, m.pfx, v3.WithPrefix(), v3.WithRev(m.myRev-1))
// release lock key if cancelled
select {
case <-ctx.Done():
m.Unlock()
default:
}
return err
}
func TestWatchDeleteEventObjectHaveLatestRV(t *testing.T) {
ctx, store, cluster := testSetup(t)
defer cluster.Terminate(t)
key, storedObj := testPropogateStore(ctx, t, store, &api.Pod{ObjectMeta: api.ObjectMeta{Name: "foo"}})
w, err := store.Watch(ctx, key, storedObj.ResourceVersion, storage.Everything)
if err != nil {
t.Fatalf("Watch failed: %v", err)
}
etcdW := cluster.RandClient().Watch(ctx, "/", clientv3.WithPrefix())
if err := store.Delete(ctx, key, &api.Pod{}, &storage.Preconditions{}); err != nil {
t.Fatalf("Delete failed: %v", err)
}
e := <-w.ResultChan()
watchedDeleteObj := e.Object.(*api.Pod)
var wres clientv3.WatchResponse
wres = <-etcdW
watchedDeleteRev, err := storage.ParseWatchResourceVersion(watchedDeleteObj.ResourceVersion)
if err != nil {
t.Fatalf("ParseWatchResourceVersion failed: %v", err)
}
if int64(watchedDeleteRev) != wres.Events[0].Kv.ModRevision {
t.Errorf("Object from delete event have version: %v, should be the same as etcd delete's mod rev: %d",
watchedDeleteRev, wres.Events[0].Kv.ModRevision)
}
}
// startWatching does:
// - get current objects if initialRev=0; set initialRev to current rev
// - watch on given key and send events to process.
func (wc *watchChan) startWatching() {
if wc.initialRev == 0 {
if err := wc.sync(); err != nil {
glog.Errorf("failed to sync with latest state: %v", err)
wc.sendError(err)
return
}
}
opts := []clientv3.OpOption{clientv3.WithRev(wc.initialRev + 1)}
if wc.recursive {
opts = append(opts, clientv3.WithPrefix())
}
wch := wc.watcher.client.Watch(wc.ctx, wc.key, opts...)
for wres := range wch {
if wres.Err() != nil {
err := wres.Err()
// If there is an error on server (e.g. compaction), the channel will return it before closed.
glog.Errorf("watch chan error: %v", err)
wc.sendError(err)
return
}
for _, e := range wres.Events {
wc.sendEvent(parseEvent(e))
}
}
}
// List implements storage.Interface.List.
func (s *store) List(ctx context.Context, key, resourceVersion string, pred storage.SelectionPredicate, listObj runtime.Object) error {
listPtr, err := meta.GetItemsPtr(listObj)
if err != nil {
return err
}
key = keyWithPrefix(s.pathPrefix, key)
// We need to make sure the key ended with "/" so that we only get children "directories".
// e.g. if we have key "/a", "/a/b", "/ab", getting keys with prefix "/a" will return all three,
// while with prefix "/a/" will return only "/a/b" which is the correct answer.
if !strings.HasSuffix(key, "/") {
key += "/"
}
getResp, err := s.client.KV.Get(ctx, key, clientv3.WithPrefix())
if err != nil {
return err
}
elems := make([]*elemForDecode, len(getResp.Kvs))
for i, kv := range getResp.Kvs {
elems[i] = &elemForDecode{
data: kv.Value,
rev: uint64(kv.ModRevision),
}
}
if err := decodeList(elems, storage.SimpleFilter(pred), listPtr, s.codec, s.versioner); err != nil {
return err
}
// update version with cluster level revision
return s.versioner.UpdateList(listObj, uint64(getResp.Header.Revision))
}
func deletePrefix(ctx context.Context, client *clientv3.Client, key string) error {
for ctx.Err() == nil {
if _, err := client.Delete(ctx, key, clientv3.WithPrefix()); err == nil {
return nil
}
}
return ctx.Err()
}
func (s *syncer) SyncBase(ctx context.Context) (<-chan clientv3.GetResponse, chan error) {
respchan := make(chan clientv3.GetResponse, 1024)
errchan := make(chan error, 1)
kapi := clientv3.NewKV(s.c)
// if rev is not specified, we will choose the most recent revision.
if s.rev == 0 {
resp, err := kapi.Get(ctx, "foo")
if err != nil {
errchan <- err
close(respchan)
close(errchan)
return respchan, errchan
}
s.rev = resp.Header.Revision
}
go func() {
defer close(respchan)
defer close(errchan)
var key string
opts := []clientv3.OpOption{clientv3.WithLimit(batchLimit), clientv3.WithRev(s.rev)}
if len(s.prefix) == 0 {
// If len(s.prefix) == 0, we will sync the entire key-value space.
// We then range from the smallest key (0x00) to the end.
opts = append(opts, clientv3.WithFromKey())
key = "\x00"
} else {
// If len(s.prefix) != 0, we will sync key-value space with given prefix.
// We then range from the prefix to the next prefix if exists. Or we will
// range from the prefix to the end if the next prefix does not exists.
opts = append(opts, clientv3.WithPrefix())
key = s.prefix
}
for {
resp, err := kapi.Get(ctx, key, opts...)
if err != nil {
errchan <- err
return
}
respchan <- (clientv3.GetResponse)(*resp)
if !resp.More {
return
}
// move to next key
key = string(append(resp.Kvs[len(resp.Kvs)-1].Key, 0))
}
}()
return respchan, errchan
}
func watchInteractiveFunc(cmd *cobra.Command, args []string) {
c := mustClientFromCmd(cmd)
reader := bufio.NewReader(os.Stdin)
for {
l, err := reader.ReadString('\n')
if err != nil {
ExitWithError(ExitInvalidInput, fmt.Errorf("Error reading watch request line: %v", err))
}
l = strings.TrimSuffix(l, "\n")
args := argify(l)
if len(args) < 2 {
fmt.Fprintf(os.Stderr, "Invalid command %s (command type or key is not provided)\n", l)
continue
}
if args[0] != "watch" {
fmt.Fprintf(os.Stderr, "Invalid command %s (only support watch)\n", l)
continue
}
flagset := NewWatchCommand().Flags()
err = flagset.Parse(args[1:])
if err != nil {
fmt.Fprintf(os.Stderr, "Invalid command %s (%v)\n", l, err)
continue
}
moreargs := flagset.Args()
if len(moreargs) < 1 || len(moreargs) > 2 {
fmt.Fprintf(os.Stderr, "Invalid command %s (Too few or many arguments)\n", l)
continue
}
var key string
_, err = fmt.Sscanf(moreargs[0], "%q", &key)
if err != nil {
key = moreargs[0]
}
opts := []clientv3.OpOption{clientv3.WithRev(watchRev)}
if len(moreargs) == 2 {
if watchPrefix {
fmt.Fprintf(os.Stderr, "`range_end` and `--prefix` cannot be set at the same time, choose one\n")
continue
}
opts = append(opts, clientv3.WithRange(moreargs[1]))
}
if watchPrefix {
opts = append(opts, clientv3.WithPrefix())
}
ch := c.Watch(context.TODO(), key, opts...)
go printWatchCh(ch)
}
}
func testWatchWithProgressNotify(t *testing.T, watchOnPut bool) {
defer testutil.AfterTest(t)
// accelerate report interval so test terminates quickly
oldpi := v3rpc.GetProgressReportInterval()
// using atomics to avoid race warnings
v3rpc.SetProgressReportInterval(3 * time.Second)
pi := 3 * time.Second
defer func() { v3rpc.SetProgressReportInterval(oldpi) }()
clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
defer clus.Terminate(t)
wc := clientv3.NewWatcher(clus.RandClient())
defer wc.Close()
opts := []clientv3.OpOption{clientv3.WithProgressNotify()}
if watchOnPut {
opts = append(opts, clientv3.WithPrefix())
}
rch := wc.Watch(context.Background(), "foo", opts...)
select {
case resp := <-rch: // wait for notification
if len(resp.Events) != 0 {
t.Fatalf("resp.Events expected none, got %+v", resp.Events)
}
case <-time.After(2 * pi):
t.Fatalf("watch response expected in %v, but timed out", pi)
}
kvc := clientv3.NewKV(clus.RandClient())
if _, err := kvc.Put(context.TODO(), "foox", "bar"); err != nil {
t.Fatal(err)
}
select {
case resp := <-rch:
if resp.Header.Revision != 2 {
t.Fatalf("resp.Header.Revision expected 2, got %d", resp.Header.Revision)
}
if watchOnPut { // wait for put if watch on the put key
ev := []*clientv3.Event{{Type: clientv3.EventTypePut,
Kv: &mvccpb.KeyValue{Key: []byte("foox"), Value: []byte("bar"), CreateRevision: 2, ModRevision: 2, Version: 1}}}
if !reflect.DeepEqual(ev, resp.Events) {
t.Fatalf("expected %+v, got %+v", ev, resp.Events)
}
} else if len(resp.Events) != 0 { // wait for notification otherwise
t.Fatalf("expected no events, but got %+v", resp.Events)
}
case <-time.After(2 * pi):
t.Fatalf("watch response expected in %v, but timed out", pi)
}
}
func prefixToKeyOption(prefix string) (key string, option clientv3.OpOption) {
if prefix == "" {
key = "\x00"
option = clientv3.WithFromKey()
} else {
key = prefix
option = clientv3.WithPrefix()
}
return key, option
}
//Fetch data from sync
func (s *Sync) Fetch(key string) (*sync.Node, error) {
node, err := s.etcdClient.Get(s.withTimeout(), key, etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
if err != nil {
return nil, err
}
dir, err := s.etcdClient.Get(s.withTimeout(), key+"/", etcd.WithPrefix(), etcd.WithSort(etcd.SortByKey, etcd.SortAscend))
if err != nil {
return nil, err
}
return s.recursiveFetch(key, node.Kvs, dir.Kvs)
}
func wipeEtcdMetadata(cfg torus.Config) error {
client, err := etcdv3.New(etcdv3.Config{Endpoints: []string{cfg.MetadataAddress}, TLS: cfg.TLS})
if err != nil {
return err
}
defer client.Close()
_, err = client.Delete(context.Background(), MkKey(), etcdv3.WithPrefix())
if err != nil {
return err
}
return nil
}
// snapshotToStdout streams a snapshot over stdout
func snapshotToStdout(c *clientv3.Client) {
// must explicitly fetch first revision since no retry on stdout
wr := <-c.Watch(context.TODO(), "", clientv3.WithPrefix(), clientv3.WithRev(1))
if wr.Err() == nil {
wr.CompactRevision = 1
}
if rev := snapshot(os.Stdout, c, wr.CompactRevision+1); rev != 0 {
err := fmt.Errorf("snapshot interrupted by compaction %v", rev)
ExitWithError(ExitInterrupted, err)
}
os.Stdout.Sync()
}
func (gw *gRPCWatcher) firstNext() ([]*naming.Update, error) {
// Use serialized request so resolution still works if the target etcd
// server is partitioned away from the quorum.
resp, err := gw.c.Get(gw.ctx, gw.target, etcd.WithPrefix(), etcd.WithSerializable())
if gw.err = err; err != nil {
return nil, err
}
updates := make([]*naming.Update, 0, len(resp.Kvs))
for _, kv := range resp.Kvs {
var jupdate naming.Update
if err := json.Unmarshal(kv.Value, &jupdate); err != nil {
continue
}
updates = append(updates, &jupdate)
}
opts := []etcd.OpOption{etcd.WithRev(resp.Header.Revision + 1), etcd.WithPrefix(), etcd.WithPrevKV()}
gw.wch = gw.c.Watch(gw.ctx, gw.target, opts...)
return updates, nil
}
func (n *ng) DeleteBackend(bk engine.BackendKey) error {
if bk.Id == "" {
return &engine.InvalidFormatError{Message: "backend id can not be empty"}
}
fs, err := n.backendUsedBy(bk)
if err != nil {
return err
}
if len(fs) != 0 {
return fmt.Errorf("can not delete backend '%v', it is in use by %s", bk, fs)
}
_, err = n.client.Delete(n.context, n.path("backends", bk.Id), etcd.WithPrefix())
return convertErr(err)
}
// snapshotToStdout streams a snapshot over stdout
func snapshotToStdout(c *clientv3.Client) {
// must explicitly fetch first revision since no retry on stdout
wapi := clientv3.NewWatcher(c)
defer wapi.Close()
wr := <-wapi.Watch(context.TODO(), "", clientv3.WithPrefix(), clientv3.WithRev(1))
if len(wr.Events) > 0 {
wr.CompactRevision = 1
}
if rev := snapshot(os.Stdout, c, wr.CompactRevision+1); rev != 0 {
err := fmt.Errorf("snapshot interrupted by compaction %v", rev)
ExitWithError(ExitInterrupted, err)
}
os.Stdout.Sync()
}
// sync tries to retrieve existing data and send them to process.
// The revision to watch will be set to the revision in response.
// All events sent will have isCreated=true
func (wc *watchChan) sync() error {
opts := []clientv3.OpOption{}
if wc.recursive {
opts = append(opts, clientv3.WithPrefix())
}
getResp, err := wc.watcher.client.Get(wc.ctx, wc.key, opts...)
if err != nil {
return err
}
wc.initialRev = getResp.Header.Revision
for _, kv := range getResp.Kvs {
wc.sendEvent(parseKV(kv))
}
return nil
}