diff options
Diffstat (limited to 'vendor/github.com/coreos/etcd/client/client.go')
| -rw-r--r-- | vendor/github.com/coreos/etcd/client/client.go | 710 |
1 files changed, 0 insertions, 710 deletions
diff --git a/vendor/github.com/coreos/etcd/client/client.go b/vendor/github.com/coreos/etcd/client/client.go deleted file mode 100644 index e6874505..00000000 --- a/vendor/github.com/coreos/etcd/client/client.go +++ /dev/null @@ -1,710 +0,0 @@ -// Copyright 2015 The etcd Authors -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package client - -import ( - "context" - "encoding/json" - "errors" - "fmt" - "io/ioutil" - "math/rand" - "net" - "net/http" - "net/url" - "sort" - "strconv" - "sync" - "time" - - "github.com/coreos/etcd/version" -) - -var ( - ErrNoEndpoints = errors.New("client: no endpoints available") - ErrTooManyRedirects = errors.New("client: too many redirects") - ErrClusterUnavailable = errors.New("client: etcd cluster is unavailable or misconfigured") - ErrNoLeaderEndpoint = errors.New("client: no leader endpoint available") - errTooManyRedirectChecks = errors.New("client: too many redirect checks") - - // oneShotCtxValue is set on a context using WithValue(&oneShotValue) so - // that Do() will not retry a request - oneShotCtxValue interface{} -) - -var DefaultRequestTimeout = 5 * time.Second - -var DefaultTransport CancelableTransport = &http.Transport{ - Proxy: http.ProxyFromEnvironment, - Dial: (&net.Dialer{ - Timeout: 30 * time.Second, - KeepAlive: 30 * time.Second, - }).Dial, - TLSHandshakeTimeout: 10 * time.Second, -} - -type EndpointSelectionMode int - -const ( - // EndpointSelectionRandom is the default value of the 'SelectionMode'. - // As the name implies, the client object will pick a node from the members - // of the cluster in a random fashion. If the cluster has three members, A, B, - // and C, the client picks any node from its three members as its request - // destination. - EndpointSelectionRandom EndpointSelectionMode = iota - - // If 'SelectionMode' is set to 'EndpointSelectionPrioritizeLeader', - // requests are sent directly to the cluster leader. This reduces - // forwarding roundtrips compared to making requests to etcd followers - // who then forward them to the cluster leader. In the event of a leader - // failure, however, clients configured this way cannot prioritize among - // the remaining etcd followers. Therefore, when a client sets 'SelectionMode' - // to 'EndpointSelectionPrioritizeLeader', it must use 'client.AutoSync()' to - // maintain its knowledge of current cluster state. - // - // This mode should be used with Client.AutoSync(). - EndpointSelectionPrioritizeLeader -) - -type Config struct { - // Endpoints defines a set of URLs (schemes, hosts and ports only) - // that can be used to communicate with a logical etcd cluster. For - // example, a three-node cluster could be provided like so: - // - // Endpoints: []string{ - // "http://node1.example.com:2379", - // "http://node2.example.com:2379", - // "http://node3.example.com:2379", - // } - // - // If multiple endpoints are provided, the Client will attempt to - // use them all in the event that one or more of them are unusable. - // - // If Client.Sync is ever called, the Client may cache an alternate - // set of endpoints to continue operation. - Endpoints []string - - // Transport is used by the Client to drive HTTP requests. If not - // provided, DefaultTransport will be used. - Transport CancelableTransport - - // CheckRedirect specifies the policy for handling HTTP redirects. - // If CheckRedirect is not nil, the Client calls it before - // following an HTTP redirect. The sole argument is the number of - // requests that have already been made. If CheckRedirect returns - // an error, Client.Do will not make any further requests and return - // the error back it to the caller. - // - // If CheckRedirect is nil, the Client uses its default policy, - // which is to stop after 10 consecutive requests. - CheckRedirect CheckRedirectFunc - - // Username specifies the user credential to add as an authorization header - Username string - - // Password is the password for the specified user to add as an authorization header - // to the request. - Password string - - // HeaderTimeoutPerRequest specifies the time limit to wait for response - // header in a single request made by the Client. The timeout includes - // connection time, any redirects, and header wait time. - // - // For non-watch GET request, server returns the response body immediately. - // For PUT/POST/DELETE request, server will attempt to commit request - // before responding, which is expected to take `100ms + 2 * RTT`. - // For watch request, server returns the header immediately to notify Client - // watch start. But if server is behind some kind of proxy, the response - // header may be cached at proxy, and Client cannot rely on this behavior. - // - // Especially, wait request will ignore this timeout. - // - // One API call may send multiple requests to different etcd servers until it - // succeeds. Use context of the API to specify the overall timeout. - // - // A HeaderTimeoutPerRequest of zero means no timeout. - HeaderTimeoutPerRequest time.Duration - - // SelectionMode is an EndpointSelectionMode enum that specifies the - // policy for choosing the etcd cluster node to which requests are sent. - SelectionMode EndpointSelectionMode -} - -func (cfg *Config) transport() CancelableTransport { - if cfg.Transport == nil { - return DefaultTransport - } - return cfg.Transport -} - -func (cfg *Config) checkRedirect() CheckRedirectFunc { - if cfg.CheckRedirect == nil { - return DefaultCheckRedirect - } - return cfg.CheckRedirect -} - -// CancelableTransport mimics net/http.Transport, but requires that -// the object also support request cancellation. -type CancelableTransport interface { - http.RoundTripper - CancelRequest(req *http.Request) -} - -type CheckRedirectFunc func(via int) error - -// DefaultCheckRedirect follows up to 10 redirects, but no more. -var DefaultCheckRedirect CheckRedirectFunc = func(via int) error { - if via > 10 { - return ErrTooManyRedirects - } - return nil -} - -type Client interface { - // Sync updates the internal cache of the etcd cluster's membership. - Sync(context.Context) error - - // AutoSync periodically calls Sync() every given interval. - // The recommended sync interval is 10 seconds to 1 minute, which does - // not bring too much overhead to server and makes client catch up the - // cluster change in time. - // - // The example to use it: - // - // for { - // err := client.AutoSync(ctx, 10*time.Second) - // if err == context.DeadlineExceeded || err == context.Canceled { - // break - // } - // log.Print(err) - // } - AutoSync(context.Context, time.Duration) error - - // Endpoints returns a copy of the current set of API endpoints used - // by Client to resolve HTTP requests. If Sync has ever been called, - // this may differ from the initial Endpoints provided in the Config. - Endpoints() []string - - // SetEndpoints sets the set of API endpoints used by Client to resolve - // HTTP requests. If the given endpoints are not valid, an error will be - // returned - SetEndpoints(eps []string) error - - // GetVersion retrieves the current etcd server and cluster version - GetVersion(ctx context.Context) (*version.Versions, error) - - httpClient -} - -func New(cfg Config) (Client, error) { - c := &httpClusterClient{ - clientFactory: newHTTPClientFactory(cfg.transport(), cfg.checkRedirect(), cfg.HeaderTimeoutPerRequest), - rand: rand.New(rand.NewSource(int64(time.Now().Nanosecond()))), - selectionMode: cfg.SelectionMode, - } - if cfg.Username != "" { - c.credentials = &credentials{ - username: cfg.Username, - password: cfg.Password, - } - } - if err := c.SetEndpoints(cfg.Endpoints); err != nil { - return nil, err - } - return c, nil -} - -type httpClient interface { - Do(context.Context, httpAction) (*http.Response, []byte, error) -} - -func newHTTPClientFactory(tr CancelableTransport, cr CheckRedirectFunc, headerTimeout time.Duration) httpClientFactory { - return func(ep url.URL) httpClient { - return &redirectFollowingHTTPClient{ - checkRedirect: cr, - client: &simpleHTTPClient{ - transport: tr, - endpoint: ep, - headerTimeout: headerTimeout, - }, - } - } -} - -type credentials struct { - username string - password string -} - -type httpClientFactory func(url.URL) httpClient - -type httpAction interface { - HTTPRequest(url.URL) *http.Request -} - -type httpClusterClient struct { - clientFactory httpClientFactory - endpoints []url.URL - pinned int - credentials *credentials - sync.RWMutex - rand *rand.Rand - selectionMode EndpointSelectionMode -} - -func (c *httpClusterClient) getLeaderEndpoint(ctx context.Context, eps []url.URL) (string, error) { - ceps := make([]url.URL, len(eps)) - copy(ceps, eps) - - // To perform a lookup on the new endpoint list without using the current - // client, we'll copy it - clientCopy := &httpClusterClient{ - clientFactory: c.clientFactory, - credentials: c.credentials, - rand: c.rand, - - pinned: 0, - endpoints: ceps, - } - - mAPI := NewMembersAPI(clientCopy) - leader, err := mAPI.Leader(ctx) - if err != nil { - return "", err - } - if len(leader.ClientURLs) == 0 { - return "", ErrNoLeaderEndpoint - } - - return leader.ClientURLs[0], nil // TODO: how to handle multiple client URLs? -} - -func (c *httpClusterClient) parseEndpoints(eps []string) ([]url.URL, error) { - if len(eps) == 0 { - return []url.URL{}, ErrNoEndpoints - } - - neps := make([]url.URL, len(eps)) - for i, ep := range eps { - u, err := url.Parse(ep) - if err != nil { - return []url.URL{}, err - } - neps[i] = *u - } - return neps, nil -} - -func (c *httpClusterClient) SetEndpoints(eps []string) error { - neps, err := c.parseEndpoints(eps) - if err != nil { - return err - } - - c.Lock() - defer c.Unlock() - - c.endpoints = shuffleEndpoints(c.rand, neps) - // We're not doing anything for PrioritizeLeader here. This is - // due to not having a context meaning we can't call getLeaderEndpoint - // However, if you're using PrioritizeLeader, you've already been told - // to regularly call sync, where we do have a ctx, and can figure the - // leader. PrioritizeLeader is also quite a loose guarantee, so deal - // with it - c.pinned = 0 - - return nil -} - -func (c *httpClusterClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) { - action := act - c.RLock() - leps := len(c.endpoints) - eps := make([]url.URL, leps) - n := copy(eps, c.endpoints) - pinned := c.pinned - - if c.credentials != nil { - action = &authedAction{ - act: act, - credentials: *c.credentials, - } - } - c.RUnlock() - - if leps == 0 { - return nil, nil, ErrNoEndpoints - } - - if leps != n { - return nil, nil, errors.New("unable to pick endpoint: copy failed") - } - - var resp *http.Response - var body []byte - var err error - cerr := &ClusterError{} - isOneShot := ctx.Value(&oneShotCtxValue) != nil - - for i := pinned; i < leps+pinned; i++ { - k := i % leps - hc := c.clientFactory(eps[k]) - resp, body, err = hc.Do(ctx, action) - if err != nil { - cerr.Errors = append(cerr.Errors, err) - if err == ctx.Err() { - return nil, nil, ctx.Err() - } - if err == context.Canceled || err == context.DeadlineExceeded { - return nil, nil, err - } - } else if resp.StatusCode/100 == 5 { - switch resp.StatusCode { - case http.StatusInternalServerError, http.StatusServiceUnavailable: - // TODO: make sure this is a no leader response - cerr.Errors = append(cerr.Errors, fmt.Errorf("client: etcd member %s has no leader", eps[k].String())) - default: - cerr.Errors = append(cerr.Errors, fmt.Errorf("client: etcd member %s returns server error [%s]", eps[k].String(), http.StatusText(resp.StatusCode))) - } - err = cerr.Errors[0] - } - if err != nil { - if !isOneShot { - continue - } - c.Lock() - c.pinned = (k + 1) % leps - c.Unlock() - return nil, nil, err - } - if k != pinned { - c.Lock() - c.pinned = k - c.Unlock() - } - return resp, body, nil - } - - return nil, nil, cerr -} - -func (c *httpClusterClient) Endpoints() []string { - c.RLock() - defer c.RUnlock() - - eps := make([]string, len(c.endpoints)) - for i, ep := range c.endpoints { - eps[i] = ep.String() - } - - return eps -} - -func (c *httpClusterClient) Sync(ctx context.Context) error { - mAPI := NewMembersAPI(c) - ms, err := mAPI.List(ctx) - if err != nil { - return err - } - - var eps []string - for _, m := range ms { - eps = append(eps, m.ClientURLs...) - } - - neps, err := c.parseEndpoints(eps) - if err != nil { - return err - } - - npin := 0 - - switch c.selectionMode { - case EndpointSelectionRandom: - c.RLock() - eq := endpointsEqual(c.endpoints, neps) - c.RUnlock() - - if eq { - return nil - } - // When items in the endpoint list changes, we choose a new pin - neps = shuffleEndpoints(c.rand, neps) - case EndpointSelectionPrioritizeLeader: - nle, err := c.getLeaderEndpoint(ctx, neps) - if err != nil { - return ErrNoLeaderEndpoint - } - - for i, n := range neps { - if n.String() == nle { - npin = i - break - } - } - default: - return fmt.Errorf("invalid endpoint selection mode: %d", c.selectionMode) - } - - c.Lock() - defer c.Unlock() - c.endpoints = neps - c.pinned = npin - - return nil -} - -func (c *httpClusterClient) AutoSync(ctx context.Context, interval time.Duration) error { - ticker := time.NewTicker(interval) - defer ticker.Stop() - for { - err := c.Sync(ctx) - if err != nil { - return err - } - select { - case <-ctx.Done(): - return ctx.Err() - case <-ticker.C: - } - } -} - -func (c *httpClusterClient) GetVersion(ctx context.Context) (*version.Versions, error) { - act := &getAction{Prefix: "/version"} - - resp, body, err := c.Do(ctx, act) - if err != nil { - return nil, err - } - - switch resp.StatusCode { - case http.StatusOK: - if len(body) == 0 { - return nil, ErrEmptyBody - } - var vresp version.Versions - if err := json.Unmarshal(body, &vresp); err != nil { - return nil, ErrInvalidJSON - } - return &vresp, nil - default: - var etcdErr Error - if err := json.Unmarshal(body, &etcdErr); err != nil { - return nil, ErrInvalidJSON - } - return nil, etcdErr - } -} - -type roundTripResponse struct { - resp *http.Response - err error -} - -type simpleHTTPClient struct { - transport CancelableTransport - endpoint url.URL - headerTimeout time.Duration -} - -func (c *simpleHTTPClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) { - req := act.HTTPRequest(c.endpoint) - - if err := printcURL(req); err != nil { - return nil, nil, err - } - - isWait := false - if req != nil && req.URL != nil { - ws := req.URL.Query().Get("wait") - if len(ws) != 0 { - var err error - isWait, err = strconv.ParseBool(ws) - if err != nil { - return nil, nil, fmt.Errorf("wrong wait value %s (%v for %+v)", ws, err, req) - } - } - } - - var hctx context.Context - var hcancel context.CancelFunc - if !isWait && c.headerTimeout > 0 { - hctx, hcancel = context.WithTimeout(ctx, c.headerTimeout) - } else { - hctx, hcancel = context.WithCancel(ctx) - } - defer hcancel() - - reqcancel := requestCanceler(c.transport, req) - - rtchan := make(chan roundTripResponse, 1) - go func() { - resp, err := c.transport.RoundTrip(req) - rtchan <- roundTripResponse{resp: resp, err: err} - close(rtchan) - }() - - var resp *http.Response - var err error - - select { - case rtresp := <-rtchan: - resp, err = rtresp.resp, rtresp.err - case <-hctx.Done(): - // cancel and wait for request to actually exit before continuing - reqcancel() - rtresp := <-rtchan - resp = rtresp.resp - switch { - case ctx.Err() != nil: - err = ctx.Err() - case hctx.Err() != nil: - err = fmt.Errorf("client: endpoint %s exceeded header timeout", c.endpoint.String()) - default: - panic("failed to get error from context") - } - } - - // always check for resp nil-ness to deal with possible - // race conditions between channels above - defer func() { - if resp != nil { - resp.Body.Close() - } - }() - - if err != nil { - return nil, nil, err - } - - var body []byte - done := make(chan struct{}) - go func() { - body, err = ioutil.ReadAll(resp.Body) - done <- struct{}{} - }() - - select { - case <-ctx.Done(): - resp.Body.Close() - <-done - return nil, nil, ctx.Err() - case <-done: - } - - return resp, body, err -} - -type authedAction struct { - act httpAction - credentials credentials -} - -func (a *authedAction) HTTPRequest(url url.URL) *http.Request { - r := a.act.HTTPRequest(url) - r.SetBasicAuth(a.credentials.username, a.credentials.password) - return r -} - -type redirectFollowingHTTPClient struct { - client httpClient - checkRedirect CheckRedirectFunc -} - -func (r *redirectFollowingHTTPClient) Do(ctx context.Context, act httpAction) (*http.Response, []byte, error) { - next := act - for i := 0; i < 100; i++ { - if i > 0 { - if err := r.checkRedirect(i); err != nil { - return nil, nil, err - } - } - resp, body, err := r.client.Do(ctx, next) - if err != nil { - return nil, nil, err - } - if resp.StatusCode/100 == 3 { - hdr := resp.Header.Get("Location") - if hdr == "" { - return nil, nil, fmt.Errorf("Location header not set") - } - loc, err := url.Parse(hdr) - if err != nil { - return nil, nil, fmt.Errorf("Location header not valid URL: %s", hdr) - } - next = &redirectedHTTPAction{ - action: act, - location: *loc, - } - continue - } - return resp, body, nil - } - - return nil, nil, errTooManyRedirectChecks -} - -type redirectedHTTPAction struct { - action httpAction - location url.URL -} - -func (r *redirectedHTTPAction) HTTPRequest(ep url.URL) *http.Request { - orig := r.action.HTTPRequest(ep) - orig.URL = &r.location - return orig -} - -func shuffleEndpoints(r *rand.Rand, eps []url.URL) []url.URL { - // copied from Go 1.9<= rand.Rand.Perm - n := len(eps) - p := make([]int, n) - for i := 0; i < n; i++ { - j := r.Intn(i + 1) - p[i] = p[j] - p[j] = i - } - neps := make([]url.URL, n) - for i, k := range p { - neps[i] = eps[k] - } - return neps -} - -func endpointsEqual(left, right []url.URL) bool { - if len(left) != len(right) { - return false - } - - sLeft := make([]string, len(left)) - sRight := make([]string, len(right)) - for i, l := range left { - sLeft[i] = l.String() - } - for i, r := range right { - sRight[i] = r.String() - } - - sort.Strings(sLeft) - sort.Strings(sRight) - for i := range sLeft { - if sLeft[i] != sRight[i] { - return false - } - } - return true -} |