Disambiguate auto_join from auto_register, rename reg to auto_advertise.

Provide an option that describes the value to the user vs the
operation performed by the software.  Momentarily introducing
`auto_join`

client/config/config.go

@@ -134,7 +134,7 @@ func DefaultConfig() *Config {
 		ConsulConfig: &config.ConsulConfig{
 			ServerServiceName: "nomad",
 			ClientServiceName: "nomad-client",
-			AutoRegister:      true,
+			AutoAdvertise:     true,
 			Timeout:           5 * time.Second,
 		},
 		LogOutput:               os.Stderr,

command/agent/agent.go

@@ -76,7 +76,7 @@ func NewAgent(config *Config, logOutput io.Writer) (*Agent, error) {
 
 	// The Nomad Agent runs the consul.Syncer regardless of whether or not the
 	// Agent is running in Client or Server mode (or both), and regardless of
-	// the consul.auto_register parameter. The Client and Server both reuse the
+	// the consul.auto_advertise parameter. The Client and Server both reuse the
 	// same consul.Syncer instance. This Syncer task periodically executes
 	// callbacks that update Consul. The reason the Syncer is always running is
 	// because one of the callbacks is attempts to self-bootstrap Nomad using
@@ -230,6 +230,12 @@ func (a *Agent) serverConfig() (*nomad.Config, error) {
 		conf.HeartbeatGrace = dur
 	}
 
+	if a.config.Consul.AutoAdvertise && a.config.Consul.ServerServiceName == "" {
+		return nil, fmt.Errorf("server_service_name must be set when auto_advertise is enabled")
+	}
+
+	// conf.ConsulConfig = a.config.Consul
+
 	return conf, nil
 }
 
@@ -333,6 +339,10 @@ func (a *Agent) clientConfig() (*clientconfig.Config, error) {
 	conf.Version = fmt.Sprintf("%s%s", a.config.Version, a.config.VersionPrerelease)
 	conf.Revision = a.config.Revision
 
+	if a.config.Consul.AutoAdvertise && a.config.Consul.ClientServiceName == "" {
+		return nil, fmt.Errorf("client_service_name must be set when auto_advertise is enabled")
+	}
+
 	conf.ConsulConfig = a.config.Consul
 
 	conf.StatsCollectionInterval = a.config.Client.StatsConfig.collectionInterval
@@ -360,7 +370,7 @@ func (a *Agent) setupServer() error {
 	a.server = server
 
 	// Create the Nomad Server services for Consul
-	if a.config.Consul.AutoRegister && a.config.Consul.ServerServiceName != "" {
+	if a.config.Consul.AutoAdvertise {
 		httpServ := &structs.Service{
 			Name:      a.config.Consul.ServerServiceName,
 			PortLabel: a.serverHTTPAddr,
@@ -413,7 +423,7 @@ func (a *Agent) setupClient() error {
 	a.client = client
 
 	// Create the Nomad Client  services for Consul
-	if a.config.Consul.AutoRegister && a.config.Consul.ClientServiceName != "" {
+	if a.config.Consul.AutoAdvertise {
 		httpServ := &structs.Service{
 			Name:      a.config.Consul.ClientServiceName,
 			PortLabel: a.clientHTTPAddr,

command/agent/config.go

@@ -362,7 +362,7 @@ func DevConfig() *Config {
 	conf.DevMode = true
 	conf.EnableDebug = true
 	conf.DisableAnonymousSignature = true
-	conf.Consul.AutoRegister = true
+	conf.Consul.AutoAdvertise = true
 	if runtime.GOOS == "darwin" {
 		conf.Client.NetworkInterface = "lo0"
 	} else if runtime.GOOS == "linux" {
@@ -393,7 +393,7 @@ func DefaultConfig() *Config {
 		Consul: &config.ConsulConfig{
 			ServerServiceName: "nomad",
 			ClientServiceName: "nomad-client",
-			AutoRegister:      true,
+			AutoAdvertise:     true,
 			Timeout:           5 * time.Second,
 		},
 		Client: &ClientConfig{

command/agent/config_parse.go

@@ -600,7 +600,7 @@ func parseConsulConfig(result **config.ConsulConfig, list *ast.ObjectList) error
 	valid := []string{
 		"address",
 		"auth",
-		"auto_register",
+		"auto_advertise",
 		"ca_file",
 		"cert_file",
 		"client_auto_join",

nomad/structs/config/consul.go

@@ -24,9 +24,10 @@ type ConsulConfig struct {
 	// clients with Consul
 	ClientServiceName string `mapstructure:"client_service_name"`
 
-	// AutoRegister determines if Nomad will register the Nomad client and
-	// server agents with Consul
-	AutoRegister bool `mapstructure:"auto_register"`
+	// AutoAdvertise determines if this Nomad Agent will advertise its
+	// services via Consul.  When true, Nomad Agent will register
+	// services with Consul.
+	AutoAdvertise bool `mapstructure:"auto_advertise"`
 
 	// Addr is the address of the local Consul agent
 	Addr string `mapstructure:"address"`
@@ -76,8 +77,8 @@ func (a *ConsulConfig) Merge(b *ConsulConfig) *ConsulConfig {
 	if b.ClientServiceName != "" {
 		result.ClientServiceName = b.ClientServiceName
 	}
-	if b.AutoRegister {
-		result.AutoRegister = true
+	if b.AutoAdvertise {
+		result.AutoAdvertise = true
 	}
 	if b.Addr != "" {
 		result.Addr = b.Addr