peer.go

Documentation: go.etcd.io/etcd/server/v3/etcdserver/api/etcdhttp

     1  // Copyright 2015 The etcd Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package etcdhttp
    16  
    17  import (
    18  	"encoding/json"
    19  	"fmt"
    20  	"net/http"
    21  	"strconv"
    22  	"strings"
    23  
    24  	"go.etcd.io/etcd/client/pkg/v3/types"
    25  	"go.etcd.io/etcd/server/v3/etcdserver"
    26  	"go.etcd.io/etcd/server/v3/etcdserver/api"
    27  	"go.etcd.io/etcd/server/v3/etcdserver/api/membership"
    28  	"go.etcd.io/etcd/server/v3/etcdserver/api/rafthttp"
    29  	"go.etcd.io/etcd/server/v3/lease/leasehttp"
    30  
    31  	"go.uber.org/zap"
    32  )
    33  
    34  const (
    35  	peerMembersPath         = "/members"
    36  	peerMemberPromotePrefix = "/members/promote/"
    37  )
    38  
    39  // NewPeerHandler generates an http.Handler to handle etcd peer requests.
    40  func NewPeerHandler(lg *zap.Logger, s etcdserver.ServerPeerV2) http.Handler {
    41  	return newPeerHandler(lg, s, s.RaftHandler(), s.LeaseHandler(), s.HashKVHandler(), s.DowngradeEnabledHandler())
    42  }
    43  
    44  func newPeerHandler(
    45  	lg *zap.Logger,
    46  	s etcdserver.Server,
    47  	raftHandler http.Handler,
    48  	leaseHandler http.Handler,
    49  	hashKVHandler http.Handler,
    50  	downgradeEnabledHandler http.Handler,
    51  ) http.Handler {
    52  	if lg == nil {
    53  		lg = zap.NewNop()
    54  	}
    55  	peerMembersHandler := newPeerMembersHandler(lg, s.Cluster())
    56  	peerMemberPromoteHandler := newPeerMemberPromoteHandler(lg, s)
    57  
    58  	mux := http.NewServeMux()
    59  	mux.HandleFunc("/", http.NotFound)
    60  	mux.Handle(rafthttp.RaftPrefix, raftHandler)
    61  	mux.Handle(rafthttp.RaftPrefix+"/", raftHandler)
    62  	mux.Handle(peerMembersPath, peerMembersHandler)
    63  	mux.Handle(peerMemberPromotePrefix, peerMemberPromoteHandler)
    64  	if leaseHandler != nil {
    65  		mux.Handle(leasehttp.LeasePrefix, leaseHandler)
    66  		mux.Handle(leasehttp.LeaseInternalPrefix, leaseHandler)
    67  	}
    68  	if downgradeEnabledHandler != nil {
    69  		mux.Handle(etcdserver.DowngradeEnabledPath, downgradeEnabledHandler)
    70  	}
    71  	if hashKVHandler != nil {
    72  		mux.Handle(etcdserver.PeerHashKVPath, hashKVHandler)
    73  	}
    74  	mux.HandleFunc(versionPath, versionHandler(s.Cluster(), serveVersion))
    75  	return mux
    76  }
    77  
    78  func newPeerMembersHandler(lg *zap.Logger, cluster api.Cluster) http.Handler {
    79  	return &peerMembersHandler{
    80  		lg:      lg,
    81  		cluster: cluster,
    82  	}
    83  }
    84  
    85  type peerMembersHandler struct {
    86  	lg      *zap.Logger
    87  	cluster api.Cluster
    88  }
    89  
    90  func newPeerMemberPromoteHandler(lg *zap.Logger, s etcdserver.Server) http.Handler {
    91  	return &peerMemberPromoteHandler{
    92  		lg:      lg,
    93  		cluster: s.Cluster(),
    94  		server:  s,
    95  	}
    96  }
    97  
    98  type peerMemberPromoteHandler struct {
    99  	lg      *zap.Logger
   100  	cluster api.Cluster
   101  	server  etcdserver.Server
   102  }
   103  
   104  func (h *peerMembersHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
   105  	if !allowMethod(w, r, "GET") {
   106  		return
   107  	}
   108  	w.Header().Set("X-Etcd-Cluster-ID", h.cluster.ID().String())
   109  
   110  	if r.URL.Path != peerMembersPath {
   111  		http.Error(w, "bad path", http.StatusBadRequest)
   112  		return
   113  	}
   114  	ms := h.cluster.Members()
   115  	w.Header().Set("Content-Type", "application/json")
   116  	if err := json.NewEncoder(w).Encode(ms); err != nil {
   117  		h.lg.Warn("failed to encode membership members", zap.Error(err))
   118  	}
   119  }
   120  
   121  func (h *peerMemberPromoteHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
   122  	if !allowMethod(w, r, "POST") {
   123  		return
   124  	}
   125  	w.Header().Set("X-Etcd-Cluster-ID", h.cluster.ID().String())
   126  
   127  	if !strings.HasPrefix(r.URL.Path, peerMemberPromotePrefix) {
   128  		http.Error(w, "bad path", http.StatusBadRequest)
   129  		return
   130  	}
   131  	idStr := strings.TrimPrefix(r.URL.Path, peerMemberPromotePrefix)
   132  	id, err := strconv.ParseUint(idStr, 10, 64)
   133  	if err != nil {
   134  		http.Error(w, fmt.Sprintf("member %s not found in cluster", idStr), http.StatusNotFound)
   135  		return
   136  	}
   137  
   138  	resp, err := h.server.PromoteMember(r.Context(), id)
   139  	if err != nil {
   140  		switch err {
   141  		case membership.ErrIDNotFound:
   142  			http.Error(w, err.Error(), http.StatusNotFound)
   143  		case membership.ErrMemberNotLearner:
   144  			http.Error(w, err.Error(), http.StatusPreconditionFailed)
   145  		case etcdserver.ErrLearnerNotReady:
   146  			http.Error(w, err.Error(), http.StatusPreconditionFailed)
   147  		default:
   148  			WriteError(h.lg, w, r, err)
   149  		}
   150  		h.lg.Warn(
   151  			"failed to promote a member",
   152  			zap.String("member-id", types.ID(id).String()),
   153  			zap.Error(err),
   154  		)
   155  		return
   156  	}
   157  
   158  	w.Header().Set("Content-Type", "application/json")
   159  	w.WriteHeader(http.StatusOK)
   160  	if err := json.NewEncoder(w).Encode(resp); err != nil {
   161  		h.lg.Warn("failed to encode members response", zap.Error(err))
   162  	}
   163  }
   164
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