core: remove all traces of unused protocol version

.changelog/11600.txt

@@ -0,0 +1,3 @@
+```release-note:improvement
+core: The unused protocol_version agent configuration value has been removed.
+```

client/client.go

@@ -749,18 +749,6 @@ func (c *Client) secretNodeID() string {
 	return c.config.Node.SecretID
 }
 
-// RPCMajorVersion returns the structs.ApiMajorVersion supported by the
-// client.
-func (c *Client) RPCMajorVersion() int {
-	return structs.ApiMajorVersion
-}
-
-// RPCMinorVersion returns the structs.ApiMinorVersion supported by the
-// client.
-func (c *Client) RPCMinorVersion() int {
-	return structs.ApiMinorVersion
-}
-
 // Shutdown is used to tear down the client
 func (c *Client) Shutdown() error {
 	c.shutdownLock.Lock()
@@ -2773,7 +2761,7 @@ DISCOLOOP:
 				continue
 			}
 			var peers []string
-			if err := c.connPool.RPC(region, addr, c.RPCMajorVersion(), "Status.Peers", rpcargs, &peers); err != nil {
+			if err := c.connPool.RPC(region, addr, "Status.Peers", rpcargs, &peers); err != nil {
 				mErr.Errors = append(mErr.Errors, err)
 				continue
 			}

client/rpc.go

@@ -74,7 +74,7 @@ TRY:
 	}
 
 	// Make the request.
-	rpcErr := c.connPool.RPC(c.Region(), server.Addr, c.RPCMajorVersion(), method, args, reply)
+	rpcErr := c.connPool.RPC(c.Region(), server.Addr, method, args, reply)
 
 	if rpcErr == nil {
 		c.fireRpcRetryWatcher()
@@ -427,7 +427,7 @@ func resolveServer(s string) (net.Addr, error) {
 // a potential error.
 func (c *Client) Ping(srv net.Addr) error {
 	var reply struct{}
-	err := c.connPool.RPC(c.Region(), srv, c.RPCMajorVersion(), "Status.Ping", struct{}{}, &reply)
+	err := c.connPool.RPC(c.Region(), srv, "Status.Ping", struct{}{}, &reply)
 	return err
 }
 

command/agent/agent.go

@@ -191,9 +191,6 @@ func convertServerConfig(agentConfig *Config) (*nomad.Config, error) {
 	if agentConfig.Server.DataDir != "" {
 		conf.DataDir = agentConfig.Server.DataDir
 	}
-	if agentConfig.Server.ProtocolVersion != 0 {
-		conf.ProtocolVersion = uint8(agentConfig.Server.ProtocolVersion)
-	}
 	if agentConfig.Server.RaftProtocol != 0 {
 		conf.RaftConfig.ProtocolVersion = raft.ProtocolVersion(agentConfig.Server.RaftProtocol)
 	}

command/agent/command.go

@@ -434,6 +434,12 @@ func (c *Command) IsValidConfig(config, cmdConfig *Config) bool {
 		}
 	}
 
+	// ProtocolVersion has never been used. Warn if it is set as someone
+	// has probably made a mistake.
+	if config.Server.ProtocolVersion != 0 {
+		c.agent.logger.Warn("Please remove deprecated protocol_version field from config.")
+	}
+
 	return true
 }
 

command/agent/config.go

@@ -367,7 +367,9 @@ type ServerConfig struct {
 
 	// ProtocolVersion is the protocol version to speak. This must be between
 	// ProtocolVersionMin and ProtocolVersionMax.
-	ProtocolVersion int `hcl:"protocol_version"`
+	//
+	// Deprecated: This has never been used and will emit a warning if nonzero.
+	ProtocolVersion int `hcl:"protocol_version" json:"-"`
 
 	// RaftProtocol is the Raft protocol version to speak. This must be from [1-3].
 	RaftProtocol int `hcl:"raft_protocol"`

command/agent/config_parse_test.go

@@ -95,7 +95,6 @@ var basicConfig = &Config{
 		AuthoritativeRegion:       "foobar",
 		BootstrapExpect:           5,
 		DataDir:                   "/tmp/data",
-		ProtocolVersion:           3,
 		RaftProtocol:              3,
 		RaftMultiplier:            helper.IntToPtr(4),
 		NumSchedulers:             helper.IntToPtr(2),
@@ -494,7 +493,6 @@ func TestConfig_Parse(t *testing.T) {
 			}
 			actual = oldDefault.Merge(actual)
 
-			//panic(fmt.Sprintf("first: %+v \n second: %+v", actual.TLSConfig, tc.Result.TLSConfig))
 			require.EqualValues(tc.Result, removeHelperAttributes(actual))
 		})
 	}

command/agent/testdata/basic.hcl

@@ -106,7 +106,6 @@ server {
   authoritative_region          = "foobar"
   bootstrap_expect              = 5
   data_dir                      = "/tmp/data"
-  protocol_version              = 3
   raft_protocol                 = 3
   num_schedulers                = 2
   enabled_schedulers            = ["test"]

command/agent/testdata/basic.json

@@ -277,7 +277,6 @@
       "node_gc_threshold": "12h",
       "non_voting_server": true,
       "num_schedulers": 2,
-      "protocol_version": 3,
       "raft_protocol": 3,
       "raft_multiplier": 4,
       "redundancy_zone": "foo",

helper/pool/pool.go

@@ -48,7 +48,6 @@ type Conn struct {
 	addr     net.Addr
 	session  *yamux.Session
 	lastUsed time.Time
-	version  int
 
 	pool *ConnPool
 
@@ -278,7 +277,7 @@ func (p *ConnPool) SetConnListener(l chan<- *Conn) {
 
 // Acquire is used to get a connection that is
 // pooled or to return a new connection
-func (p *ConnPool) acquire(region string, addr net.Addr, version int) (*Conn, error) {
+func (p *ConnPool) acquire(region string, addr net.Addr) (*Conn, error) {
 	// Check to see if there's a pooled connection available. This is up
 	// here since it should the vastly more common case than the rest
 	// of the code here.
@@ -305,7 +304,7 @@ func (p *ConnPool) acquire(region string, addr net.Addr, version int) (*Conn, er
 	// If we are the lead thread, make the new connection and then wake
 	// everybody else up to see if we got it.
 	if isLeadThread {
-		c, err := p.getNewConn(region, addr, version)
+		c, err := p.getNewConn(region, addr)
 		p.Lock()
 		delete(p.limiter, addr.String())
 		close(wait)
@@ -349,7 +348,7 @@ func (p *ConnPool) acquire(region string, addr net.Addr, version int) (*Conn, er
 }
 
 // getNewConn is used to return a new connection
-func (p *ConnPool) getNewConn(region string, addr net.Addr, version int) (*Conn, error) {
+func (p *ConnPool) getNewConn(region string, addr net.Addr) (*Conn, error) {
 	// Try to dial the conn
 	conn, err := net.DialTimeout("tcp", addr.String(), 10*time.Second)
 	if err != nil {
@@ -404,7 +403,6 @@ func (p *ConnPool) getNewConn(region string, addr net.Addr, version int) (*Conn,
 		session:  session,
 		clients:  list.New(),
 		lastUsed: time.Now(),
-		version:  version,
 		pool:     p,
 	}
 	return c, nil
@@ -429,12 +427,12 @@ func (p *ConnPool) clearConn(conn *Conn) {
 	}
 }
 
-// getClient is used to get a usable client for an address and protocol version
-func (p *ConnPool) getRPCClient(region string, addr net.Addr, version int) (*Conn, *StreamClient, error) {
+// getClient is used to get a usable client for an address
+func (p *ConnPool) getRPCClient(region string, addr net.Addr) (*Conn, *StreamClient, error) {
 	retries := 0
 START:
 	// Try to get a conn first
-	conn, err := p.acquire(region, addr, version)
+	conn, err := p.acquire(region, addr)
 	if err != nil {
 		return nil, nil, fmt.Errorf("failed to get conn: %v", err)
 	}
@@ -457,8 +455,8 @@ START:
 
 // StreamingRPC is used to make an streaming RPC call.  Callers must
 // close the connection when done.
-func (p *ConnPool) StreamingRPC(region string, addr net.Addr, version int) (net.Conn, error) {
-	conn, err := p.acquire(region, addr, version)
+func (p *ConnPool) StreamingRPC(region string, addr net.Addr) (net.Conn, error) {
+	conn, err := p.acquire(region, addr)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get conn: %v", err)
 	}
@@ -477,9 +475,9 @@ func (p *ConnPool) StreamingRPC(region string, addr net.Addr, version int) (net.
 }
 
 // RPC is used to make an RPC call to a remote host
-func (p *ConnPool) RPC(region string, addr net.Addr, version int, method string, args interface{}, reply interface{}) error {
+func (p *ConnPool) RPC(region string, addr net.Addr, method string, args interface{}, reply interface{}) error {
 	// Get a usable client
-	conn, sc, err := p.getRPCClient(region, addr, version)
+	conn, sc, err := p.getRPCClient(region, addr)
 	if err != nil {
 		return fmt.Errorf("rpc error: %w", err)
 	}

helper/pool/pool_test.go

@@ -8,7 +8,6 @@ import (
 
 	"github.com/hashicorp/nomad/helper/freeport"
 	"github.com/hashicorp/nomad/helper/testlog"
-	"github.com/hashicorp/nomad/nomad/structs"
 	"github.com/stretchr/testify/require"
 )
 
@@ -50,7 +49,7 @@ func TestConnPool_ConnListener(t *testing.T) {
 	pool.SetConnListener(c)
 
 	// Make an RPC
-	_, err = pool.acquire("test", addr, structs.ApiMajorVersion)
+	_, err = pool.acquire("test", addr)
 	require.Nil(err)
 
 	// Assert we get a connection.

nomad/client_rpc.go

@@ -188,8 +188,7 @@ func (s *Server) serverWithNodeConn(nodeID, region string) (*serverParts, error)
 
 		// Make the RPC
 		var resp structs.NodeConnQueryResponse
-		err := s.connPool.RPC(s.config.Region, server.Addr, server.MajorVersion,
-			"Status.HasNodeConn", &req, &resp)
+		err := s.connPool.RPC(s.config.Region, server.Addr, "Status.HasNodeConn", &req, &resp)
 		if err != nil {
 			multierror.Append(&rpcErr, fmt.Errorf("failed querying server %q: %v", server.Addr.String(), err))
 			continue

nomad/config.go

@@ -1,7 +1,6 @@
 package nomad
 
 import (
-	"fmt"
 	"io"
 	"net"
 	"os"
@@ -27,23 +26,6 @@ const (
 	DefaultSerfPort = 4648
 )
 
-// These are the protocol versions that Nomad can understand
-const (
-	ProtocolVersionMin uint8 = 1
-	ProtocolVersionMax       = 1
-)
-
-// ProtocolVersionMap is the mapping of Nomad protocol versions
-// to Serf protocol versions. We mask the Serf protocols using
-// our own protocol version.
-var protocolVersionMap map[uint8]uint8
-
-func init() {
-	protocolVersionMap = map[uint8]uint8{
-		1: 4,
-	}
-}
-
 func DefaultRPCAddr() *net.TCPAddr {
 	return &net.TCPAddr{IP: net.ParseIP("127.0.0.1"), Port: 4647}
 }
@@ -93,10 +75,6 @@ type Config struct {
 	// Logger is the logger used by the server.
 	Logger log.InterceptLogger
 
-	// ProtocolVersion is the protocol version to speak. This must be between
-	// ProtocolVersionMin and ProtocolVersionMax.
-	ProtocolVersion uint8
-
 	// RPCAddr is the RPC address used by Nomad. This should be reachable
 	// by the other servers and clients
 	RPCAddr *net.TCPAddr
@@ -370,18 +348,6 @@ type Config struct {
 	DeploymentQueryRateLimit float64
 }
 
-// CheckVersion is used to check if the ProtocolVersion is valid
-func (c *Config) CheckVersion() error {
-	if c.ProtocolVersion < ProtocolVersionMin {
-		return fmt.Errorf("Protocol version '%d' too low. Must be in range: [%d, %d]",
-			c.ProtocolVersion, ProtocolVersionMin, ProtocolVersionMax)
-	} else if c.ProtocolVersion > ProtocolVersionMax {
-		return fmt.Errorf("Protocol version '%d' too high. Must be in range: [%d, %d]",
-			c.ProtocolVersion, ProtocolVersionMin, ProtocolVersionMax)
-	}
-	return nil
-}
-
 // DefaultConfig returns the default configuration. Only used as the basis for
 // merging agent or test parameters.
 func DefaultConfig() *Config {
@@ -396,7 +362,6 @@ func DefaultConfig() *Config {
 		Datacenter:                       DefaultDC,
 		NodeName:                         hostname,
 		NodeID:                           uuid.Generate(),
-		ProtocolVersion:                  ProtocolVersionMax,
 		RaftConfig:                       raft.DefaultConfig(),
 		RaftTimeout:                      10 * time.Second,
 		LogOutput:                        os.Stderr,

nomad/node_endpoint.go

@@ -267,8 +267,6 @@ func (n *Node) constructNodeServerInfoResponse(snap *state.StateSnapshot, reply
 		reply.Servers = append(reply.Servers,
 			&structs.NodeServerInfo{
 				RPCAdvertiseAddr: v.RPCAddr.String(),
-				RPCMajorVersion:  int32(v.MajorVersion),
-				RPCMinorVersion:  int32(v.MinorVersion),
 				Datacenter:       v.Datacenter,
 			})
 	}

nomad/rpc.go

@@ -644,7 +644,7 @@ func (r *rpcHandler) forwardLeader(server *serverParts, method string, args inte
 	if server == nil {
 		return structs.ErrNoLeader
 	}
-	return r.connPool.RPC(r.config.Region, server.Addr, server.MajorVersion, method, args, reply)
+	return r.connPool.RPC(r.config.Region, server.Addr, method, args, reply)
 }
 
 // forwardServer is used to forward an RPC call to a particular server
@@ -653,7 +653,7 @@ func (r *rpcHandler) forwardServer(server *serverParts, method string, args inte
 	if server == nil {
 		return errors.New("must be given a valid server address")
 	}
-	return r.connPool.RPC(r.config.Region, server.Addr, server.MajorVersion, method, args, reply)
+	return r.connPool.RPC(r.config.Region, server.Addr, method, args, reply)
 }
 
 func (r *rpcHandler) findRegionServer(region string) (*serverParts, error) {
@@ -680,7 +680,7 @@ func (r *rpcHandler) forwardRegion(region, method string, args interface{}, repl
 
 	// Forward to remote Nomad
 	metrics.IncrCounter([]string{"nomad", "rpc", "cross-region", region}, 1)
-	return r.connPool.RPC(region, server.Addr, server.MajorVersion, method, args, reply)
+	return r.connPool.RPC(region, server.Addr, method, args, reply)
 }
 
 func (r *rpcHandler) getServer(region, serverID string) (*serverParts, error) {
@@ -708,7 +708,7 @@ func (r *rpcHandler) getServer(region, serverID string) (*serverParts, error) {
 // initial handshake, returning the connection or an error. It is the callers
 // responsibility to close the connection if there is no returned error.
 func (r *rpcHandler) streamingRpc(server *serverParts, method string) (net.Conn, error) {
-	c, err := r.connPool.StreamingRPC(r.config.Region, server.Addr, server.MajorVersion)
+	c, err := r.connPool.StreamingRPC(r.config.Region, server.Addr)
 	if err != nil {
 		return nil, err
 	}

nomad/serf.go

@@ -164,7 +164,7 @@ func (s *Server) maybeBootstrap() {
 
 		// Retry with exponential backoff to get peer status from this server
 		for attempt := uint(0); attempt < maxPeerRetries; attempt++ {
-			if err := s.connPool.RPC(s.config.Region, server.Addr, server.MajorVersion,
+			if err := s.connPool.RPC(s.config.Region, server.Addr,
 				"Status.Peers", req, &peers); err != nil {
 				nextRetry := (1 << attempt) * peerRetryBase
 				s.logger.Error("failed to confirm peer status", "peer", server.Name, "error", err, "retry", nextRetry)

nomad/server.go

@@ -291,10 +291,6 @@ type endpoints struct {
 // NewServer is used to construct a new Nomad server from the
 // configuration, potentially returning an error
 func NewServer(config *Config, consulCatalog consul.CatalogAPI, consulConfigEntries consul.ConfigAPI, consulACLs consul.ACLsAPI) (*Server, error) {
-	// Check the protocol version
-	if err := config.CheckVersion(); err != nil {
-		return nil, err
-	}
 
 	// Create an eval broker
 	evalBroker, err := NewEvalBroker(
@@ -1398,8 +1394,6 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string) (
 	conf.Tags["role"] = "nomad"
 	conf.Tags["region"] = s.config.Region
 	conf.Tags["dc"] = s.config.Datacenter
-	conf.Tags["vsn"] = fmt.Sprintf("%d", structs.ApiMajorVersion)
-	conf.Tags["mvn"] = fmt.Sprintf("%d", structs.ApiMinorVersion)
 	conf.Tags["build"] = s.config.Build
 	conf.Tags["raft_vsn"] = fmt.Sprintf("%d", s.config.RaftConfig.ProtocolVersion)
 	conf.Tags["id"] = s.config.NodeID
@@ -1433,7 +1427,6 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string) (
 			return nil, err
 		}
 	}
-	conf.ProtocolVersion = protocolVersionMap[s.config.ProtocolVersion]
 	conf.RejoinAfterLeave = true
 	// LeavePropagateDelay is used to make sure broadcasted leave intents propagate
 	// This value was tuned using https://www.serf.io/docs/internals/simulator.html to

nomad/stats_fetcher.go

@@ -43,7 +43,7 @@ func NewStatsFetcher(logger log.Logger, pool *pool.ConnPool, region string) *Sta
 func (f *StatsFetcher) fetch(server *serverParts, replyCh chan *autopilot.ServerStats) {
 	var args struct{}
 	var reply autopilot.ServerStats
-	err := f.pool.RPC(f.region, server.Addr, server.MajorVersion, "Status.RaftStats", &args, &reply)
+	err := f.pool.RPC(f.region, server.Addr, "Status.RaftStats", &args, &reply)
 	if err != nil {
 		f.logger.Warn("failed retrieving server health", "server", server.Name, "error", err)
 	} else {