| // 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 main |
| |
| import ( |
| "io/ioutil" |
| "log" |
| "net/http" |
| "strconv" |
| |
| "github.com/coreos/etcd/raft/raftpb" |
| ) |
| |
| // Handler for a http based key-value store backed by raft |
| type httpKVAPI struct { |
| store *kvstore |
| confChangeC chan<- raftpb.ConfChange |
| } |
| |
| func (h *httpKVAPI) ServeHTTP(w http.ResponseWriter, r *http.Request) { |
| key := r.RequestURI |
| switch { |
| case r.Method == "PUT": |
| v, err := ioutil.ReadAll(r.Body) |
| if err != nil { |
| log.Printf("Failed to read on PUT (%v)\n", err) |
| http.Error(w, "Failed on PUT", http.StatusBadRequest) |
| return |
| } |
| |
| h.store.Propose(key, string(v)) |
| |
| // Optimistic-- no waiting for ack from raft. Value is not yet |
| // committed so a subsequent GET on the key may return old value |
| w.WriteHeader(http.StatusNoContent) |
| case r.Method == "GET": |
| if v, ok := h.store.Lookup(key); ok { |
| w.Write([]byte(v)) |
| } else { |
| http.Error(w, "Failed to GET", http.StatusNotFound) |
| } |
| case r.Method == "POST": |
| url, err := ioutil.ReadAll(r.Body) |
| if err != nil { |
| log.Printf("Failed to read on POST (%v)\n", err) |
| http.Error(w, "Failed on POST", http.StatusBadRequest) |
| return |
| } |
| |
| nodeId, err := strconv.ParseUint(key[1:], 0, 64) |
| if err != nil { |
| log.Printf("Failed to convert ID for conf change (%v)\n", err) |
| http.Error(w, "Failed on POST", http.StatusBadRequest) |
| return |
| } |
| |
| cc := raftpb.ConfChange{ |
| Type: raftpb.ConfChangeAddNode, |
| NodeID: nodeId, |
| Context: url, |
| } |
| h.confChangeC <- cc |
| |
| // As above, optimistic that raft will apply the conf change |
| w.WriteHeader(http.StatusNoContent) |
| case r.Method == "DELETE": |
| nodeId, err := strconv.ParseUint(key[1:], 0, 64) |
| if err != nil { |
| log.Printf("Failed to convert ID for conf change (%v)\n", err) |
| http.Error(w, "Failed on DELETE", http.StatusBadRequest) |
| return |
| } |
| |
| cc := raftpb.ConfChange{ |
| Type: raftpb.ConfChangeRemoveNode, |
| NodeID: nodeId, |
| } |
| h.confChangeC <- cc |
| |
| // As above, optimistic that raft will apply the conf change |
| w.WriteHeader(http.StatusNoContent) |
| default: |
| w.Header().Set("Allow", "PUT") |
| w.Header().Add("Allow", "GET") |
| w.Header().Add("Allow", "POST") |
| w.Header().Add("Allow", "DELETE") |
| http.Error(w, "Method not allowed", http.StatusMethodNotAllowed) |
| } |
| } |
| |
| // serveHttpKVAPI starts a key-value server with a GET/PUT API and listens. |
| func serveHttpKVAPI(kv *kvstore, port int, confChangeC chan<- raftpb.ConfChange, errorC <-chan error) { |
| srv := http.Server{ |
| Addr: ":" + strconv.Itoa(port), |
| Handler: &httpKVAPI{ |
| store: kv, |
| confChangeC: confChangeC, |
| }, |
| } |
| go func() { |
| if err := srv.ListenAndServe(); err != nil { |
| log.Fatal(err) |
| } |
| }() |
| |
| // exit when raft goes down |
| if err, ok := <-errorC; ok { |
| log.Fatal(err) |
| } |
| } |