func (h serverHandler) serveKeys(w http.ResponseWriter, r *http.Request) {
if !allowMethod(w, r.Method, "GET", "PUT", "POST", "DELETE") {
return
}
ctx, cancel := context.WithTimeout(context.Background(), h.timeout)
defer cancel()
rr, err := parseRequest(r, etcdserver.GenID())
if err != nil {
writeError(w, err)
return
}
resp, err := h.server.Do(ctx, rr)
if err != nil {
writeError(w, err)
return
}
switch {
case resp.Event != nil:
if err := writeEvent(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()
handleWatch(ctx, w, resp.Watcher, rr.Stream, h.timer)
default:
writeError(w, errors.New("received response with no Event/Watcher!"))
}
}
// 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.
// TODO: take care of info fetched from cluster store after having reconfig.
func (s *EtcdServer) publish(retryInterval time.Duration) {
m := *s.ClusterStore.Get().FindName(s.name)
m.ClientURLs = s.clientURLs.StringSlice()
b, err := json.Marshal(m)
if err != nil {
log.Printf("etcdserver: json marshal error: %v", err)
return
}
req := pb.Request{
ID: GenID(),
Method: "PUT",
Path: m.storeKey(),
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 the cluster", m)
return
case ErrStopped:
log.Printf("etcdserver: aborting publish because server is stopped")
return
default:
log.Printf("etcdserver: publish error: %v", err)
}
}
}
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
}
func (c *httpClient) Get(key string) (*Response, error) {
get := &getAction{
Key: key,
Recursive: false,
}
ctx, cancel := context.WithTimeout(context.Background(), c.timeout)
httpresp, body, err := c.do(ctx, get)
cancel()
if err != nil {
return nil, err
}
return unmarshalHTTPResponse(httpresp.StatusCode, body)
}
func (c *httpClient) Create(key, val string, ttl time.Duration) (*Response, error) {
uintTTL := uint64(ttl.Seconds())
create := &createAction{
Key: key,
Value: val,
TTL: &uintTTL,
}
ctx, cancel := context.WithTimeout(context.Background(), c.timeout)
httpresp, body, err := c.do(ctx, create)
cancel()
if err != nil {
return nil, err
}
return unmarshalHTTPResponse(httpresp.StatusCode, body)
}
// 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: GenID(),
Time: time.Now().UnixNano(),
}
data, err := req.Marshal()
if err != nil {
log.Printf("marshal request %#v error: %v", req, err)
return
}
// There is no promise that node has leader when do SYNC request,
// so it uses goroutine to propose.
go func() {
s.Node.Propose(ctx, data)
cancel()
}()
}
func (h serverHandler) serveKeys(w http.ResponseWriter, r *http.Request) {
if !allowMethod(w, r.Method, "GET", "PUT", "POST", "DELETE") {
return
}
ctx, cancel := context.WithTimeout(context.Background(), h.timeout)
defer cancel()
rr, err := parseRequest(r, etcdserver.GenID())
if err != nil {
writeError(w, err)
return
}
resp, err := h.server.Do(ctx, rr)
if err != nil {
writeError(w, err)
return
}
var ev *store.Event
switch {
case resp.Event != nil:
ev = resp.Event
case resp.Watcher != nil:
if ev, err = waitForEvent(ctx, w, resp.Watcher); err != nil {
http.Error(w, err.Error(), http.StatusGatewayTimeout)
return
}
default:
writeError(w, errors.New("received response with no Event/Watcher!"))
return
}
if err = writeEvent(w, ev); err != nil {
// Should never be reached
log.Println("error writing event: %v", err)
}
}
func (h Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// TODO: set read/write timeout?
timeout := h.Timeout
if timeout == 0 {
timeout = DefaultTimeout
}
ctx, cancel := context.WithTimeout(context.Background(), timeout)
defer cancel()
switch {
case strings.HasPrefix(r.URL.Path, "/raft"):
h.serveRaft(ctx, w, r)
case strings.HasPrefix(r.URL.Path, keysPrefix):
h.serveKeys(ctx, w, r)
case strings.HasPrefix(r.URL.Path, machinesPrefix):
h.serveMachines(w, r)
default:
http.NotFound(w, r)
}
}