Refactor commands.

server/join_command.go

@@ -0,0 +1,84 @@
+package server
+
+import (
+	"encoding/binary"
+	"fmt"
+	"path"
+
+	etcdErr "github.com/coreos/etcd/error"
+	"github.com/coreos/etcd/log"
+	"github.com/coreos/etcd/store"
+	"github.com/coreos/go-raft"
+)
+
+func init() {
+	raft.RegisterCommand(&JoinCommand{})
+}
+
+// The JoinCommand adds a node to the cluster.
+type JoinCommand struct {
+	RaftVersion    string `json:"raftVersion"`
+	Name           string `json:"name"`
+	RaftURL        string `json:"raftURL"`
+	EtcdURL        string `json:"etcdURL"`
+	MaxClusterSize int    `json:"maxClusterSize"`
+}
+
+func NewJoinCommand(version, name, raftUrl, etcdUrl string, maxClusterSize int) *JoinCommand {
+	return &JoinCommand{
+		RaftVersion:    version,
+		Name:           name,
+		RaftURL:        raftUrl,
+		EtcdURL:        etcdUrl,
+		MaxClusterSize: maxClusterSize,
+	}
+}
+
+// The name of the join command in the log
+func (c *JoinCommand) CommandName() string {
+	return "etcd:join"
+}
+
+// Join a server to the cluster
+func (c *JoinCommand) Apply(server *raft.Server) (interface{}, error) {
+	s, _ := server.StateMachine().(*store.Store)
+	r, _ := server.Context().(*RaftServer)
+
+	// check if the join command is from a previous machine, who lost all its previous log.
+	e, _ := s.Get(path.Join("/_etcd/machines", c.Name), false, false, server.CommitIndex(), server.Term())
+
+	b := make([]byte, 8)
+	binary.PutUvarint(b, server.CommitIndex())
+
+	if e != nil {
+		return b, nil
+	}
+
+	// check machine number in the cluster
+	if s.MachineCount() == c.MaxClusterSize {
+		log.Debug("Reject join request from ", c.Name)
+		return []byte{0}, etcdErr.NewError(etcdErr.EcodeNoMoreMachine, "", server.CommitIndex(), server.Term())
+	}
+
+	addNameToURL(c.Name, c.RaftVersion, c.RaftURL, c.EtcdURL)
+
+	// add peer in raft
+	err := server.AddPeer(c.Name, "")
+
+	// add machine in etcd storage
+	key := path.Join("_etcd/machines", c.Name)
+	value := fmt.Sprintf("raft=%s&etcd=%s&raftVersion=%s", c.RaftURL, c.EtcdURL, c.RaftVersion)
+	s.Create(key, value, false, false, store.Permanent, server.CommitIndex(), server.Term())
+
+	// add peer stats
+	if c.Name != r.Name() {
+		r.followersStats.Followers[c.Name] = &raftFollowerStats{}
+		r.followersStats.Followers[c.Name].Latency.Minimum = 1 << 63
+	}
+
+	return b, err
+}
+
+func (c *JoinCommand) NodeName() string {
+	return c.Name
+}