Machine join/remove v2 API.

server/remove_command.go

@@ -2,6 +2,7 @@ package server
 
 import (
 	"encoding/binary"
+	"encoding/json"
 	"os"
 
 	"github.com/coreos/etcd/log"
@@ -9,21 +10,22 @@ import (
 )
 
 func init() {
-	raft.RegisterCommand(&RemoveCommand{})
+	raft.RegisterCommand(&RemoveCommandV1{})
+	raft.RegisterCommand(&RemoveCommandV2{})
 }
 
-// The RemoveCommand removes a server from the cluster.
-type RemoveCommand struct {
+// The RemoveCommandV1 removes a server from the cluster.
+type RemoveCommandV1 struct {
 	Name string `json:"name"`
 }
 
 // The name of the remove command in the log
-func (c *RemoveCommand) CommandName() string {
+func (c *RemoveCommandV1) CommandName() string {
 	return "etcd:remove"
 }
 
 // Remove a server from the cluster
-func (c *RemoveCommand) Apply(context raft.Context) (interface{}, error) {
+func (c *RemoveCommandV1) Apply(context raft.Context) (interface{}, error) {
 	ps, _ := context.Server().Context().(*PeerServer)
 
 	// If this is a proxy then remove it and exit.
@@ -70,3 +72,65 @@ func (c *RemoveCommand) Apply(context raft.Context) (interface{}, error) {
 
 	return b, err
 }
+
+// RemoveCommandV2 represents a command to remove a machine from the server.
+type RemoveCommandV2 struct {
+	Name string `json:"name"`
+}
+
+// CommandName returns the name of the command.
+func (c *RemoveCommandV2) CommandName() string {
+	return "etcd:v2:remove"
+}
+
+// Apply removes the given machine from the cluster.
+func (c *RemoveCommandV2) Apply(context raft.Context) (interface{}, error) {
+	ps, _ := context.Server().Context().(*PeerServer)
+	ret, _ := json.Marshal(removeMessageV2{CommitIndex: context.CommitIndex()})
+
+	// If this is a proxy then remove it and exit.
+	if ps.registry.ProxyExists(c.Name) {
+		if err := ps.registry.UnregisterProxy(c.Name); err != nil {
+			return nil, err
+		}
+		return ret, nil
+	}
+
+	// Remove node from the shared registry.
+	err := ps.registry.UnregisterPeer(c.Name)
+
+	// Delete from stats
+	delete(ps.followersStats.Followers, c.Name)
+
+	if err != nil {
+		log.Debugf("Error while unregistering: %s (%v)", c.Name, err)
+		return nil, err
+	}
+
+	// Remove peer in raft
+	if err := context.Server().RemovePeer(c.Name); err != nil {
+		log.Debugf("Unable to remove peer: %s (%v)", c.Name, err)
+		return nil, err
+	}
+
+	if c.Name == context.Server().Name() {
+		// the removed node is this node
+
+		// if the node is not replaying the previous logs
+		// and the node has sent out a join request in this
+		// start. It is sure that this node received a new remove
+		// command and need to be removed
+		if context.CommitIndex() > ps.joinIndex && ps.joinIndex != 0 {
+			log.Debugf("server [%s] is removed", context.Server().Name())
+			os.Exit(0)
+		} else {
+			// else ignore remove
+			log.Debugf("ignore previous remove command.")
+		}
+	}
+	return ret, nil
+}
+
+type removeMessageV2 struct {
+	CommitIndex uint64 `json:"commitIndex"`
+}