From 78918848bd61d22faec0f5612b27ca50b78121b3 Mon Sep 17 00:00:00 2001
From: Gyuho Lee <gyuhox@gmail.com>
Date: Thu, 22 Feb 2018 21:19:23 -0800
Subject: [PATCH] etcdserver: support Raft Pre-Vote

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>
---
 etcdserver/config.go | 3 +++
 etcdserver/raft.go   | 3 +++
 etcdserver/server.go | 6 ++++++
 3 files changed, 12 insertions(+)

diff --git a/etcdserver/config.go b/etcdserver/config.go
index 4626ab85d..7a362aa13 100644
--- a/etcdserver/config.go
+++ b/etcdserver/config.go
@@ -76,6 +76,9 @@ type ServerConfig struct {
 	InitialCorruptCheck bool
 	CorruptCheckTime    time.Duration
 
+	// PreVote is true to enable Raft Pre-Vote.
+	PreVote bool
+
 	Debug bool
 }
 
diff --git a/etcdserver/raft.go b/etcdserver/raft.go
index 9695da80e..1fa085905 100644
--- a/etcdserver/raft.go
+++ b/etcdserver/raft.go
@@ -411,6 +411,7 @@ func startNode(cfg ServerConfig, cl *membership.RaftCluster, ids []types.ID) (id
 		MaxSizePerMsg:   maxSizePerMsg,
 		MaxInflightMsgs: maxInflightMsgs,
 		CheckQuorum:     true,
+		PreVote:         cfg.PreVote,
 	}
 
 	n = raft.StartNode(c, peers)
@@ -445,6 +446,7 @@ func restartNode(cfg ServerConfig, snapshot *raftpb.Snapshot) (types.ID, *member
 		MaxSizePerMsg:   maxSizePerMsg,
 		MaxInflightMsgs: maxInflightMsgs,
 		CheckQuorum:     true,
+		PreVote:         cfg.PreVote,
 	}
 
 	n := raft.RestartNode(c)
@@ -501,6 +503,7 @@ func restartAsStandaloneNode(cfg ServerConfig, snapshot *raftpb.Snapshot) (types
 		MaxSizePerMsg:   maxSizePerMsg,
 		MaxInflightMsgs: maxInflightMsgs,
 		CheckQuorum:     true,
+		PreVote:         cfg.PreVote,
 	}
 	n := raft.RestartNode(c)
 	raftStatus = n.Status
diff --git a/etcdserver/server.go b/etcdserver/server.go
index 5bd489c12..aa2321752 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -258,6 +258,12 @@ type EtcdServer struct {
 // NewServer creates a new EtcdServer from the supplied configuration. The
 // configuration is considered static for the lifetime of the EtcdServer.
 func NewServer(cfg ServerConfig) (srv *EtcdServer, err error) {
+	if cfg.PreVote {
+		plog.Info("Raft Pre-Vote is enabled")
+	} else {
+		plog.Info("Raft Pre-Vote is disabled")
+	}
+
 	st := v2store.New(StoreClusterPrefix, StoreKeysPrefix)
 
 	var (