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@@ -0,0 +1,203 @@
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+package server
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+
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+import (
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+ "bytes"
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+ "encoding/binary"
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+ "encoding/json"
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+ "errors"
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+ "fmt"
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+ "io/ioutil"
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+ "net/http"
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+ "net/url"
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+ "strconv"
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+
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+ etcdErr "github.com/coreos/etcd/error"
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+ "github.com/coreos/etcd/log"
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+)
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+
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+// Client sends various requests using HTTP API.
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+// It is different from raft communication, and doesn't record anything in the log.
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+// Public functions return "etcd/error".Error intentionally to figure out
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+// etcd error code easily.
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+// TODO(yichengq): It is similar to go-etcd. But it could have many efforts
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+// to integrate the two. Leave it for further discussion.
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+type Client struct {
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+ http.Client
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+}
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+
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+func NewClient(transport http.RoundTripper) *Client {
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+ return &Client{http.Client{Transport: transport}}
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+}
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+
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+// CheckVersion checks whether the version is available.
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+func (c *Client) CheckVersion(url string, version int) (bool, *etcdErr.Error) {
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+ resp, err := c.Get(url + fmt.Sprintf("/version/%d/check", version))
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+ if err != nil {
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+ return false, clientError(err)
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+ }
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+
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+ defer resp.Body.Close()
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+
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+ return resp.StatusCode == 200, nil
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+}
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+
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+// GetVersion fetches the peer version of a cluster.
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+func (c *Client) GetVersion(url string) (int, *etcdErr.Error) {
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+ resp, err := c.Get(url + "/version")
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+ if err != nil {
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+ return 0, clientError(err)
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+ }
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+
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+ defer resp.Body.Close()
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+
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+ body, err := ioutil.ReadAll(resp.Body)
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+ if err != nil {
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+ return 0, clientError(err)
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+ }
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+
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+ // Parse version number.
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+ version, _ := strconv.Atoi(string(body))
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+ return version, nil
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+}
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+
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+// AddMachine adds machine to the cluster.
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+// The first return value is the commit index of join command.
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+func (c *Client) AddMachine(url string, cmd *JoinCommand) (uint64, *etcdErr.Error) {
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+ b, _ := json.Marshal(cmd)
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+ url = url + "/join"
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+
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+ log.Infof("Send Join Request to %s", url)
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+ resp, err := c.put(url, b)
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+ if err != nil {
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+ return 0, clientError(err)
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+ }
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+ defer resp.Body.Close()
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+
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+ if err := c.checkErrorResponse(resp); err != nil {
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+ return 0, err
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+ }
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+ b, err = ioutil.ReadAll(resp.Body)
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+ if err != nil {
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+ return 0, clientError(err)
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+ }
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+ index, numRead := binary.Uvarint(b)
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+ if numRead < 0 {
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+ return 0, clientError(fmt.Errorf("buf too small, or value too large"))
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+ }
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+ return index, nil
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+}
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+
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+func (c *Client) parseJSONResponse(resp *http.Response, val interface{}) *etcdErr.Error {
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+ defer resp.Body.Close()
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+
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+ if err := c.checkErrorResponse(resp); err != nil {
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+ return err
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+ }
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+ if err := json.NewDecoder(resp.Body).Decode(val); err != nil {
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+ log.Debugf("Error parsing join response: %v", err)
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+ return clientError(err)
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+ }
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+ return nil
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+}
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+
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+func (c *Client) checkErrorResponse(resp *http.Response) *etcdErr.Error {
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+ if resp.StatusCode != http.StatusOK {
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+ uerr := &etcdErr.Error{}
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+ if err := json.NewDecoder(resp.Body).Decode(uerr); err != nil {
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+ log.Debugf("Error parsing response to etcd error: %v", err)
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+ return clientError(err)
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+ }
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+ return uerr
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+ }
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+ return nil
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+}
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+
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+// put sends server side PUT request.
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+// It always follows redirects instead of stopping according to RFC 2616.
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+func (c *Client) put(urlStr string, body []byte) (*http.Response, error) {
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+ req, err := http.NewRequest("PUT", urlStr, bytes.NewBuffer(body))
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+ if err != nil {
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+ return nil, err
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+ }
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+ return c.doAlwaysFollowingRedirects(req, body)
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+}
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+
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+// doAlwaysFollowingRedirects provides similar functionality as standard one,
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+// but it does redirect with the same method for PUT or POST requests.
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+// Part of the code is borrowed from pkg/net/http/client.go.
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+func (c *Client) doAlwaysFollowingRedirects(ireq *http.Request, body []byte) (resp *http.Response, err error) {
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+ var base *url.URL
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+ redirectChecker := c.CheckRedirect
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+ if redirectChecker == nil {
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+ redirectChecker = defaultCheckRedirect
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+ }
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+ var via []*http.Request
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+
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+ req := ireq
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+ urlStr := "" // next relative or absolute URL to fetch (after first request)
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+ for redirect := 0; ; redirect++ {
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+ if redirect != 0 {
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+ req, err = http.NewRequest(ireq.Method, urlStr, bytes.NewBuffer(body))
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+ if err != nil {
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+ break
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+ }
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+ req.URL = base.ResolveReference(req.URL)
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+ if len(via) > 0 {
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+ // Add the Referer header.
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+ lastReq := via[len(via)-1]
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+ if lastReq.URL.Scheme != "https" {
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+ req.Header.Set("Referer", lastReq.URL.String())
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+ }
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+
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+ err = redirectChecker(req, via)
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+ if err != nil {
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+ break
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+ }
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+ }
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+ }
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+
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+ urlStr = req.URL.String()
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+ // It uses exported Do method here.
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+ // It is more elegant to use unexported send method, but that will
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+ // introduce many redundant code.
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+ if resp, err = c.Do(req); err != nil {
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+ break
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+ }
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+
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+ if shouldExtraRedirectPost(resp.StatusCode) {
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+ resp.Body.Close()
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+ if urlStr = resp.Header.Get("Location"); urlStr == "" {
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+ err = errors.New(fmt.Sprintf("%d response missing Location header", resp.StatusCode))
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+ break
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+ }
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+ base = req.URL
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+ via = append(via, req)
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+ continue
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+ }
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+ return
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+ }
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+
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+ if resp != nil {
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+ resp.Body.Close()
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+ }
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+ return nil, err
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+}
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+
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+func shouldExtraRedirectPost(statusCode int) bool {
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+ switch statusCode {
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+ case http.StatusMovedPermanently, http.StatusTemporaryRedirect:
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+ return true
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+ }
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+ return false
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+}
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+
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+func defaultCheckRedirect(req *http.Request, via []*http.Request) error {
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+ if len(via) >= 10 {
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+ return errors.New("stopped after 10 redirects")
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+ }
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+ return nil
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+}
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+
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+func clientError(err error) *etcdErr.Error {
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+ return etcdErr.NewError(etcdErr.EcodeClientInternal, err.Error(), 0)
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+}
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Yicheng Qin