func (d *discovery) checkCluster() ([]*client.Node, int, uint64, error) {
configKey := path.Join("/", d.cluster, "_config")
ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
// find cluster size
resp, err := d.c.Get(ctx, path.Join(configKey, "size"), nil)
cancel()
if err != nil {
if eerr, ok := err.(*client.Error); ok && eerr.Code == client.ErrorCodeKeyNotFound {
return nil, 0, 0, ErrSizeNotFound
}
if err == context.DeadlineExceeded {
return d.checkClusterRetry()
}
return nil, 0, 0, err
}
size, err := strconv.Atoi(resp.Node.Value)
if err != nil {
return nil, 0, 0, ErrBadSizeKey
}
ctx, cancel = context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
resp, err = d.c.Get(ctx, d.cluster, nil)
cancel()
if err != nil {
if err == context.DeadlineExceeded {
return d.checkClusterRetry()
}
return nil, 0, 0, err
}
nodes := make([]*client.Node, 0)
// append non-config keys to nodes
for _, n := range resp.Node.Nodes {
if !(path.Base(n.Key) == path.Base(configKey)) {
nodes = append(nodes, n)
}
}
snodes := sortableNodes{nodes}
sort.Sort(snodes)
// find self position
for i := range nodes {
if path.Base(nodes[i].Key) == path.Base(d.selfKey()) {
break
}
if i >= size-1 {
return nodes[:size], size, resp.Index, ErrFullCluster
}
}
return nodes, size, resp.Index, nil
}
// publish registers server information into the cluster. The information
// is the JSON representation of this server's member struct, updated with the
// static clientURLs of the server.
// The function keeps attempting to register until it succeeds,
// or its server is stopped.
func (s *EtcdServer) publish(retryInterval time.Duration) {
b, err := json.Marshal(s.attributes)
if err != nil {
log.Printf("etcdserver: json marshal error: %v", err)
return
}
req := pb.Request{
Method: "PUT",
Path: MemberAttributesStorePath(s.id),
Val: string(b),
}
for {
ctx, cancel := context.WithTimeout(context.Background(), retryInterval)
_, err := s.Do(ctx, req)
cancel()
switch err {
case nil:
log.Printf("etcdserver: published %+v to cluster %s", s.attributes, s.Cluster.ID())
return
case ErrStopped:
log.Printf("etcdserver: aborting publish because server is stopped")
return
default:
log.Printf("etcdserver: publish error: %v", err)
}
}
}
func (h *keysHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if !allowMethod(w, r.Method, "HEAD", "GET", "PUT", "POST", "DELETE") {
return
}
w.Header().Set("X-Etcd-Cluster-ID", h.clusterInfo.ID().String())
ctx, cancel := context.WithTimeout(context.Background(), h.timeout)
defer cancel()
rr, err := parseKeyRequest(r, clockwork.NewRealClock())
if err != nil {
writeError(w, err)
return
}
// The path must be valid at this point (we've parsed the request successfully).
if !hasKeyPrefixAccess(h.sec, r, r.URL.Path[len(keysPrefix):]) {
writeNoAuth(w)
return
}
resp, err := h.server.Do(ctx, rr)
if err != nil {
err = trimErrorPrefix(err, etcdserver.StoreKeysPrefix)
writeError(w, err)
return
}
switch {
case resp.Event != nil:
if err := writeKeyEvent(w, resp.Event, h.timer); err != nil {
// Should never be reached
log.Printf("error writing event: %v", err)
}
case resp.Watcher != nil:
ctx, cancel := context.WithTimeout(context.Background(), defaultWatchTimeout)
defer cancel()
handleKeyWatch(ctx, w, resp.Watcher, rr.Stream, h.timer)
default:
writeError(w, errors.New("received response with no Event/Watcher!"))
}
}
func (s *Store) requestResource(res string, dir bool) (etcdserver.Response, error) {
ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
defer cancel()
p := path.Join(StorePermsPrefix, res)
rr := etcdserverpb.Request{
Method: "GET",
Path: p,
Dir: dir,
}
return s.server.Do(ctx, rr)
}
func (s *Store) deleteResource(res string) (etcdserver.Response, error) {
ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
defer cancel()
pex := true
p := path.Join(StorePermsPrefix, res)
rr := etcdserverpb.Request{
Method: "DELETE",
Path: p,
PrevExist: &pex,
}
return s.server.Do(ctx, rr)
}
func ExampleWithTimeout() {
// Pass a context with a timeout to tell a blocking function that it
// should abandon its work after the timeout elapses.
ctx, _ := context.WithTimeout(context.Background(), 100*time.Millisecond)
select {
case <-time.After(200 * time.Millisecond):
fmt.Println("overslept")
case <-ctx.Done():
fmt.Println(ctx.Err()) // prints "context deadline exceeded"
}
// Output:
// context deadline exceeded
}
// sync proposes a SYNC request and is non-blocking.
// This makes no guarantee that the request will be proposed or performed.
// The request will be cancelled after the given timeout.
func (s *EtcdServer) sync(timeout time.Duration) {
ctx, cancel := context.WithTimeout(context.Background(), timeout)
req := pb.Request{
Method: "SYNC",
ID: s.reqIDGen.Next(),
Time: time.Now().UnixNano(),
}
data := pbutil.MustMarshal(&req)
// There is no promise that node has leader when do SYNC request,
// so it uses goroutine to propose.
go func() {
s.r.Propose(ctx, data)
cancel()
}()
}
func (d *discovery) createSelf(contents string) error {
ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
resp, err := d.c.Create(ctx, d.selfKey(), contents)
cancel()
if err != nil {
if eerr, ok := err.(*client.Error); ok && eerr.Code == client.ErrorCodeNodeExist {
return ErrDuplicateID
}
return err
}
// ensure self appears on the server we connected to
w := d.c.Watcher(d.selfKey(), &client.WatcherOptions{AfterIndex: resp.Node.CreatedIndex - 1})
_, err = w.Next(context.Background())
return err
}
func (s *Store) setResource(res string, value interface{}, prevexist bool) (etcdserver.Response, error) {
ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
defer cancel()
data, err := json.Marshal(value)
if err != nil {
return etcdserver.Response{}, err
}
p := path.Join(StorePermsPrefix, res)
rr := etcdserverpb.Request{
Method: "PUT",
Path: p,
Val: string(data),
PrevExist: &prevexist,
}
return s.server.Do(ctx, rr)
}
func getPeersFromDiscoveryURL(discoverURL string) ([]string, error) {
if discoverURL == "" {
return nil, nil
}
u, err := url.Parse(discoverURL)
if err != nil {
return nil, err
}
token := u.Path
u.Path = ""
cfg := client.Config{
Transport: &http.Transport{},
Endpoints: []string{u.String()},
}
c, err := client.New(cfg)
if err != nil {
return nil, err
}
dc := client.NewKeysAPIWithPrefix(c, "")
ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
resp, err := dc.Get(ctx, token, nil)
cancel()
if err != nil {
return nil, err
}
peers := make([]string, 0)
// append non-config keys to peers
for _, n := range resp.Node.Nodes {
if g := path.Base(n.Key); g == "_config" || g == "_state" {
continue
}
peers = append(peers, n.Value)
}
return peers, nil
}
func (s *Store) ensureSecurityDirectories() error {
for _, res := range []string{StorePermsPrefix, StorePermsPrefix + "/users/", StorePermsPrefix + "/roles/"} {
ctx, cancel := context.WithTimeout(context.Background(), s.timeout)
defer cancel()
pe := false
rr := etcdserverpb.Request{
Method: "PUT",
Path: res,
Dir: true,
PrevExist: &pe,
}
_, err := s.server.Do(ctx, rr)
if err != nil {
if e, ok := err.(*etcderr.Error); ok {
if e.ErrorCode == etcderr.EcodeNodeExist {
continue
}
}
log.Println("security: Trying to create security directories in the store; failed:", err)
return err
}
}
return nil
}
func (h *membersHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if !allowMethod(w, r.Method, "GET", "POST", "DELETE", "PUT") {
return
}
if !hasWriteRootAccess(h.sec, r) {
writeNoAuth(w)
return
}
w.Header().Set("X-Etcd-Cluster-ID", h.clusterInfo.ID().String())
ctx, cancel := context.WithTimeout(context.Background(), defaultServerTimeout)
defer cancel()
switch r.Method {
case "GET":
switch trimPrefix(r.URL.Path, membersPrefix) {
case "":
mc := newMemberCollection(h.clusterInfo.Members())
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(mc); err != nil {
log.Printf("etcdhttp: %v", err)
}
case "leader":
id := h.server.Leader()
if id == 0 {
writeError(w, httptypes.NewHTTPError(http.StatusServiceUnavailable, "During election"))
return
}
m := newMember(h.clusterInfo.Member(id))
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(m); err != nil {
log.Printf("etcdhttp: %v", err)
}
default:
writeError(w, httptypes.NewHTTPError(http.StatusNotFound, "Not found"))
}
case "POST":
req := httptypes.MemberCreateRequest{}
if ok := unmarshalRequest(r, &req, w); !ok {
return
}
now := h.clock.Now()
m := etcdserver.NewMember("", req.PeerURLs, "", &now)
err := h.server.AddMember(ctx, *m)
switch {
case err == etcdserver.ErrIDExists || err == etcdserver.ErrPeerURLexists:
writeError(w, httptypes.NewHTTPError(http.StatusConflict, err.Error()))
return
case err != nil:
log.Printf("etcdhttp: error adding node %s: %v", m.ID, err)
writeError(w, err)
return
}
res := newMember(m)
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusCreated)
if err := json.NewEncoder(w).Encode(res); err != nil {
log.Printf("etcdhttp: %v", err)
}
case "DELETE":
id, ok := getID(r.URL.Path, w)
if !ok {
return
}
err := h.server.RemoveMember(ctx, uint64(id))
switch {
case err == etcdserver.ErrIDRemoved:
writeError(w, httptypes.NewHTTPError(http.StatusGone, fmt.Sprintf("Member permanently removed: %s", id)))
case err == etcdserver.ErrIDNotFound:
writeError(w, httptypes.NewHTTPError(http.StatusNotFound, fmt.Sprintf("No such member: %s", id)))
case err != nil:
log.Printf("etcdhttp: error removing node %s: %v", id, err)
writeError(w, err)
default:
w.WriteHeader(http.StatusNoContent)
}
case "PUT":
id, ok := getID(r.URL.Path, w)
if !ok {
return
}
req := httptypes.MemberUpdateRequest{}
if ok := unmarshalRequest(r, &req, w); !ok {
return
}
m := etcdserver.Member{
ID: id,
RaftAttributes: etcdserver.RaftAttributes{PeerURLs: req.PeerURLs.StringSlice()},
}
err := h.server.UpdateMember(ctx, m)
switch {
case err == etcdserver.ErrPeerURLexists:
writeError(w, httptypes.NewHTTPError(http.StatusConflict, err.Error()))
case err == etcdserver.ErrIDNotFound:
writeError(w, httptypes.NewHTTPError(http.StatusNotFound, fmt.Sprintf("No such member: %s", id)))
case err != nil:
log.Printf("etcdhttp: error updating node %s: %v", m.ID, err)
writeError(w, err)
default:
w.WriteHeader(http.StatusNoContent)
}
}
}