// getVersion returns the Versions of the given member via its
// peerURLs. Returns the last error if it fails to get the version.
func getVersion(m *membership.Member, rt http.RoundTripper) (*version.Versions, error) {
cc := &http.Client{
Transport: rt,
}
var (
err error
resp *http.Response
)
for _, u := range m.PeerURLs {
resp, err = cc.Get(u + "/version")
if err != nil {
plog.Warningf("failed to reach the peerURL(%s) of member %s (%v)", u, m.ID, err)
continue
}
// etcd 2.0 does not have version endpoint on peer url.
if resp.StatusCode == http.StatusNotFound {
httputil.GracefulClose(resp)
return &version.Versions{
Server: "2.0.0",
Cluster: "2.0.0",
}, nil
}
var b []byte
b, err = ioutil.ReadAll(resp.Body)
resp.Body.Close()
if err != nil {
plog.Warningf("failed to read out the response body from the peerURL(%s) of member %s (%v)", u, m.ID, err)
continue
}
var vers version.Versions
if err = json.Unmarshal(b, &vers); err != nil {
plog.Warningf("failed to unmarshal the response body got from the peerURL(%s) of member %s (%v)", u, m.ID, err)
continue
}
return &vers, nil
}
return nil, err
}
// post posts the given request.
// It returns nil when request is sent out and processed successfully.
func (s *snapshotSender) post(req *http.Request) (err error) {
cancel := httputil.RequestCanceler(req)
type responseAndError struct {
resp *http.Response
body []byte
err error
}
result := make(chan responseAndError, 1)
go func() {
resp, err := s.tr.pipelineRt.RoundTrip(req)
if err != nil {
result <- responseAndError{resp, nil, err}
return
}
// close the response body when timeouts.
// prevents from reading the body forever when the other side dies right after
// successfully receives the request body.
time.AfterFunc(snapResponseReadTimeout, func() { httputil.GracefulClose(resp) })
body, err := ioutil.ReadAll(resp.Body)
result <- responseAndError{resp, body, err}
}()
select {
case <-s.stopc:
cancel()
return errStopped
case r := <-result:
if r.err != nil {
return r.err
}
return checkPostResponse(r.resp, r.body, req, s.to)
}
}
func (cr *streamReader) dial(t streamType) (io.ReadCloser, error) {
u := cr.picker.pick()
uu := u
uu.Path = path.Join(t.endpoint(), cr.local.String())
req, err := http.NewRequest("GET", uu.String(), nil)
if err != nil {
cr.picker.unreachable(u)
return nil, fmt.Errorf("failed to make http request to %s (%v)", u, err)
}
req.Header.Set("X-Server-From", cr.local.String())
req.Header.Set("X-Server-Version", version.Version)
req.Header.Set("X-Min-Cluster-Version", version.MinClusterVersion)
req.Header.Set("X-Etcd-Cluster-ID", cr.cid.String())
req.Header.Set("X-Raft-To", cr.remote.String())
setPeerURLsHeader(req, cr.tr.URLs)
cr.mu.Lock()
select {
case <-cr.stopc:
cr.mu.Unlock()
return nil, fmt.Errorf("stream reader is stopped")
default:
}
cr.cancel = httputil.RequestCanceler(cr.tr.streamRt, req)
cr.mu.Unlock()
resp, err := cr.tr.streamRt.RoundTrip(req)
if err != nil {
cr.picker.unreachable(u)
return nil, err
}
rv := serverVersion(resp.Header)
lv := semver.Must(semver.NewVersion(version.Version))
if compareMajorMinorVersion(rv, lv) == -1 && !checkStreamSupport(rv, t) {
httputil.GracefulClose(resp)
cr.picker.unreachable(u)
return nil, errUnsupportedStreamType
}
switch resp.StatusCode {
case http.StatusGone:
httputil.GracefulClose(resp)
cr.picker.unreachable(u)
err := fmt.Errorf("the member has been permanently removed from the cluster")
select {
case cr.errorc <- err:
default:
}
return nil, err
case http.StatusOK:
return resp.Body, nil
case http.StatusNotFound:
httputil.GracefulClose(resp)
cr.picker.unreachable(u)
return nil, fmt.Errorf("remote member %s could not recognize local member", cr.remote)
case http.StatusPreconditionFailed:
b, err := ioutil.ReadAll(resp.Body)
if err != nil {
cr.picker.unreachable(u)
return nil, err
}
httputil.GracefulClose(resp)
cr.picker.unreachable(u)
switch strings.TrimSuffix(string(b), "\n") {
case errIncompatibleVersion.Error():
plog.Errorf("request sent was ignored by peer %s (server version incompatible)", cr.remote)
return nil, errIncompatibleVersion
case errClusterIDMismatch.Error():
plog.Errorf("request sent was ignored (cluster ID mismatch: remote[%s]=%s, local=%s)",
cr.remote, resp.Header.Get("X-Etcd-Cluster-ID"), cr.cid)
return nil, errClusterIDMismatch
default:
return nil, fmt.Errorf("unhandled error %q when precondition failed", string(b))
}
default:
httputil.GracefulClose(resp)
cr.picker.unreachable(u)
return nil, fmt.Errorf("unhandled http status %d", resp.StatusCode)
}
}
func readResponse(resp *http.Response) (b []byte, err error) {
b, err = ioutil.ReadAll(resp.Body)
httputil.GracefulClose(resp)
return
}