Added support for v2 raft APIs and -raft-protocol option

command/agent/agent.go

@@ -22,6 +22,7 @@ import (
 	"github.com/hashicorp/nomad/nomad"
 	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/hashicorp/nomad/nomad/structs/config"
+	"github.com/hashicorp/raft"
 )
 
 const (
@@ -141,6 +142,9 @@ func convertServerConfig(agentConfig *Config, logOutput io.Writer) (*nomad.Confi
 	if agentConfig.Server.ProtocolVersion != 0 {
 		conf.ProtocolVersion = uint8(agentConfig.Server.ProtocolVersion)
 	}
+	if agentConfig.Server.RaftProtocol != 0 {
+		conf.RaftConfig.ProtocolVersion = raft.ProtocolVersion(agentConfig.Server.RaftProtocol)
+	}
 	if agentConfig.Server.NumSchedulers != 0 {
 		conf.NumSchedulers = agentConfig.Server.NumSchedulers
 	}

command/agent/command.go

@@ -83,6 +83,7 @@ func (c *Command) readConfig() *Config {
 	flags.IntVar(&cmdConfig.Server.RetryMaxAttempts, "retry-max", 0, "")
 	flags.StringVar(&cmdConfig.Server.RetryInterval, "retry-interval", "", "")
 	flags.StringVar(&cmdConfig.Server.EncryptKey, "encrypt", "", "gossip encryption key")
+	flags.IntVar(&cmdConfig.Server.RaftProtocol, "raft-protocol", 0, "")
 
 	// Client-only options
 	flags.StringVar(&cmdConfig.Client.StateDir, "state-dir", "", "")
@@ -876,6 +877,10 @@ Server Options:
     Address of an agent to join at start time. Can be specified
     multiple times.
 
+  -raft-protocol=<num>
+    The Raft protocol version to use. Used for enabling certain Autopilot
+    features. Defaults to 2.
+
   -retry-join=<address>
     Address of an agent to join at start time with retries enabled.
     Can be specified multiple times.

command/agent/config.go

@@ -256,6 +256,9 @@ type ServerConfig struct {
 	// ProtocolVersionMin and ProtocolVersionMax.
 	ProtocolVersion int `mapstructure:"protocol_version"`
 
+	// RaftProtocol is the Raft protocol version to speak. This must be from [1-3].
+	RaftProtocol int `mapstructure:"raft_protocol"`
+
 	// NumSchedulers is the number of scheduler thread that are run.
 	// This can be as many as one per core, or zero to disable this server
 	// from doing any scheduling work.
@@ -976,6 +979,9 @@ func (a *ServerConfig) Merge(b *ServerConfig) *ServerConfig {
 	if b.ProtocolVersion != 0 {
 		result.ProtocolVersion = b.ProtocolVersion
 	}
+	if b.RaftProtocol != 0 {
+		result.RaftProtocol = b.RaftProtocol
+	}
 	if b.NumSchedulers != 0 {
 		result.NumSchedulers = b.NumSchedulers
 	}

command/agent/config_test.go

@@ -234,6 +234,7 @@ func TestConfig_Merge(t *testing.T) {
 			BootstrapExpect:        2,
 			DataDir:                "/tmp/data2",
 			ProtocolVersion:        2,
+			RaftProtocol:           2,
 			NumSchedulers:          2,
 			EnabledSchedulers:      []string{structs.JobTypeBatch},
 			NodeGCThreshold:        "12h",

command/operator_raft_list.go

@@ -79,14 +79,14 @@ func (c *OperatorRaftListCommand) Run(args []string) int {
 	}
 
 	// Format it as a nice table.
-	result := []string{"Node|ID|Address|State|Voter"}
+	result := []string{"Node|ID|Address|State|Voter|RaftProtocol"}
 	for _, s := range reply.Servers {
 		state := "follower"
 		if s.Leader {
 			state = "leader"
 		}
-		result = append(result, fmt.Sprintf("%s|%s|%s|%s|%v",
-			s.Node, s.ID, s.Address, state, s.Voter))
+		result = append(result, fmt.Sprintf("%s|%s|%s|%s|%v|%s",
+			s.Node, s.ID, s.Address, state, s.Voter, s.RaftProtocol))
 	}
 	c.Ui.Output(columnize.SimpleFormat(result))