add server join info to server and client

client/client.go

@@ -283,7 +283,7 @@ func NewClient(cfg *config.Config, consulCatalog consul.CatalogAPI, consulServic
 	// Set the preconfigured list of static servers
 	c.configLock.RLock()
 	if len(c.configCopy.Servers) > 0 {
-		if err := c.setServersImpl(c.configCopy.Servers, true); err != nil {
+		if _, err := c.setServersImpl(c.configCopy.Servers, true); err != nil {
 			logger.Printf("[WARN] client: None of the configured servers are valid: %v", err)
 		}
 	}
@@ -623,7 +623,7 @@ func (c *Client) GetServers() []string {
 
 // SetServers sets a new list of nomad servers to connect to. As long as one
 // server is resolvable no error is returned.
-func (c *Client) SetServers(in []string) error {
+func (c *Client) SetServers(in []string) (int, error) {
 	return c.setServersImpl(in, false)
 }
 
@@ -633,7 +633,7 @@ func (c *Client) SetServers(in []string) error {
 //
 // Force should be used when setting the servers from the initial configuration
 // since the server may be starting up in parallel and initial pings may fail.
-func (c *Client) setServersImpl(in []string, force bool) error {
+func (c *Client) setServersImpl(in []string, force bool) (int, error) {
 	var mu sync.Mutex
 	var wg sync.WaitGroup
 	var merr multierror.Error
@@ -673,13 +673,13 @@ func (c *Client) setServersImpl(in []string, force bool) error {
 	// Only return errors if no servers are valid
 	if len(endpoints) == 0 {
 		if len(merr.Errors) > 0 {
-			return merr.ErrorOrNil()
+			return 0, merr.ErrorOrNil()
 		}
-		return noServersErr
+		return 0, noServersErr
 	}
 
 	c.servers.SetServers(endpoints)
-	return nil
+	return len(endpoints), nil
 }
 
 // restoreState is used to restore our state from the data dir

client/client_test.go

@@ -975,13 +975,13 @@ func TestClient_ServerList(t *testing.T) {
 	if s := client.GetServers(); len(s) != 0 {
 		t.Fatalf("expected server lit to be empty but found: %+q", s)
 	}
-	if err := client.SetServers(nil); err != noServersErr {
+	if _, err := client.SetServers(nil); err != noServersErr {
 		t.Fatalf("expected setting an empty list to return a 'no servers' error but received %v", err)
 	}
-	if err := client.SetServers([]string{"123.456.13123.123.13:80"}); err == nil {
+	if _, err := client.SetServers([]string{"123.456.13123.123.13:80"}); err == nil {
 		t.Fatalf("expected setting a bad server to return an error")
 	}
-	if err := client.SetServers([]string{"123.456.13123.123.13:80", "127.0.0.1:1234", "127.0.0.1"}); err == nil {
+	if _, err := client.SetServers([]string{"123.456.13123.123.13:80", "127.0.0.1:1234", "127.0.0.1"}); err == nil {
 		t.Fatalf("expected setting at least one good server to succeed but received: %v", err)
 	}
 	s := client.GetServers()

command/agent/agent_endpoint.go

@@ -222,7 +222,7 @@ func (s *HTTPServer) updateServers(resp http.ResponseWriter, req *http.Request)
 
 	// Set the servers list into the client
 	s.agent.logger.Printf("[TRACE] Adding servers %+q to the client's primary server list", servers)
-	if err := client.SetServers(servers); err != nil {
+	if _, err := client.SetServers(servers); err != nil {
 		s.agent.logger.Printf("[ERR] Attempt to add servers %q to client failed: %v", servers, err)
 		//TODO is this the right error to return?
 		return nil, CodedError(400, err.Error())

command/agent/command.go

@@ -549,13 +549,49 @@ func (c *Command) Run(args []string) int {
 	// Start retry join process
 	c.retryJoinErrCh = make(chan struct{})
 
+	if config.Server.Enabled && len(config.Server.RetryJoin) != 0 {
 		joiner := retryJoiner{
-		join:     c.agent.server.Join,
 			discover:      &discover.Discover{},
 			errCh:         c.retryJoinErrCh,
 			logger:        c.agent.logger,
+			serverJoin:    c.agent.server.Join,
+			serverEnabled: true,
+		}
+
+		// This is for backwards compatibility, this should be removed in Nomad
+		// 0.10 and only ServerJoin should be declared on the server
+		serverJoinInfo := &ServerJoin{
+			RetryJoin:        config.Server.RetryJoin,
+			StartJoin:        config.Server.StartJoin,
+			RetryMaxAttempts: config.Server.RetryMaxAttempts,
+			RetryInterval:    config.Server.RetryInterval,
+		}
+		go joiner.RetryJoin(serverJoinInfo)
+	}
+
+	if config.Server.Enabled && config.Server.ServerJoin != nil {
+		joiner := retryJoiner{
+			discover:      &discover.Discover{},
+			errCh:         c.retryJoinErrCh,
+			logger:        c.agent.logger,
+			serverJoin:    c.agent.server.Join,
+			serverEnabled: true,
+		}
+
+		go joiner.RetryJoin(config.Server.ServerJoin)
+	}
+
+	if config.Client.Enabled && config.Client.ServerJoin != nil {
+		joiner := retryJoiner{
+			discover:      &discover.Discover{},
+			errCh:         c.retryJoinErrCh,
+			logger:        c.agent.logger,
+			clientJoin:    c.agent.client.SetServers,
+			clientEnabled: true,
+		}
+
+		go joiner.RetryJoin(config.Client.ServerJoin)
 	}
-	go joiner.RetryJoin(config)
 
 	// Wait for exit
 	return c.handleSignals()

command/agent/config-test-fixtures/basic.hcl

@@ -19,6 +19,7 @@ advertise {
 	rpc = "127.0.0.3"
 	serf = "127.0.0.4"
 }
+
 client {
 	enabled = true
 	state_dir = "/tmp/client-state"
@@ -29,6 +30,13 @@ client {
 		foo = "bar"
 		baz = "zip"
 	}
+  server_join_info {
+    retry_join = [ "1.1.1.1", "2.2.2.2" ]
+      start_join = [ "1.1.1.1", "2.2.2.2" ]
+      retry_max = 3
+      retry_interval = "15s"
+  }
+
 	options {
 		foo = "bar"
 		baz = "zip"
@@ -86,6 +94,12 @@ server {
 	redundancy_zone = "foo"
 	upgrade_version = "0.8.0"
 	encrypt = "abc"
+  server_join_info {
+    retry_join = [ "1.1.1.1", "2.2.2.2" ]
+      start_join = [ "1.1.1.1", "2.2.2.2" ]
+      retry_max = 3
+      retry_interval = "15s"
+  }
 }
 acl {
     enabled = true

command/agent/config.go

@@ -217,6 +217,9 @@ type ClientConfig struct {
 	// NoHostUUID disables using the host's UUID and will force generation of a
 	// random UUID.
 	NoHostUUID *bool `mapstructure:"no_host_uuid"`
+
+	// ServerJoin contains information that is used to attempt to join servers
+	ServerJoin *ServerJoin `mapstructure:"server_join_info"`
 }
 
 // ACLConfig is configuration specific to the ACL system
@@ -311,19 +314,23 @@ type ServerConfig struct {
 	// StartJoin is a list of addresses to attempt to join when the
 	// agent starts. If Serf is unable to communicate with any of these
 	// addresses, then the agent will error and exit.
+	// Deprecated in Nomad 0.10
 	StartJoin []string `mapstructure:"start_join"`
 
 	// RetryJoin is a list of addresses to join with retry enabled.
+	// Deprecated in Nomad 0.10
 	RetryJoin []string `mapstructure:"retry_join"`
 
 	// RetryMaxAttempts specifies the maximum number of times to retry joining a
 	// host on startup. This is useful for cases where we know the node will be
 	// online eventually.
+	// Deprecated in Nomad 0.10
 	RetryMaxAttempts int `mapstructure:"retry_max"`
 
 	// RetryInterval specifies the amount of time to wait in between join
 	// attempts on agent start. The minimum allowed value is 1 second and
 	// the default is 30s.
+	// Deprecated in Nomad 0.10
 	RetryInterval string        `mapstructure:"retry_interval"`
 	retryInterval time.Duration `mapstructure:"-"`
 
@@ -346,6 +353,32 @@ type ServerConfig struct {
 
 	// Encryption key to use for the Serf communication
 	EncryptKey string `mapstructure:"encrypt" json:"-"`
+
+	// ServerJoin contains information that is used to attempt to join servers
+	ServerJoin *ServerJoin `mapstructure:"server_join_info"`
+}
+
+// ServerJoin is used in both clients and servers to bootstrap connections to
+// servers
+type ServerJoin struct {
+	// StartJoin is a list of addresses to attempt to join when the
+	// agent starts. If Serf is unable to communicate with any of these
+	// addresses, then the agent will error and exit.
+	StartJoin []string `mapstructure:"start_join"`
+
+	// RetryJoin is a list of addresses to join with retry enabled.
+	RetryJoin []string `mapstructure:"retry_join"`
+
+	// RetryMaxAttempts specifies the maximum number of times to retry joining a
+	// host on startup. This is useful for cases where we know the node will be
+	// online eventually.
+	RetryMaxAttempts int `mapstructure:"retry_max"`
+
+	// RetryInterval specifies the amount of time to wait in between join
+	// attempts on agent start. The minimum allowed value is 1 second and
+	// the default is 30s.
+	RetryInterval string        `mapstructure:"retry_interval"`
+	retryInterval time.Duration `mapstructure:"-"`
 }
 
 // EncryptBytes returns the encryption key configured.
@@ -1055,6 +1088,9 @@ func (a *ServerConfig) Merge(b *ServerConfig) *ServerConfig {
 	if b.EncryptKey != "" {
 		result.EncryptKey = b.EncryptKey
 	}
+	if b.ServerJoin != nil {
+		result.ServerJoin = b.ServerJoin
+	}
 
 	// Add the schedulers
 	result.EnabledSchedulers = append(result.EnabledSchedulers, b.EnabledSchedulers...)
@@ -1162,6 +1198,10 @@ func (a *ClientConfig) Merge(b *ClientConfig) *ClientConfig {
 		result.ChrootEnv[k] = v
 	}
 
+	if b.ServerJoin != nil {
+		result.ServerJoin = b.ServerJoin
+	}
+
 	return &result
 }
 

command/agent/config_parse.go

@@ -370,6 +370,7 @@ func parseClient(result **ClientConfig, list *ast.ObjectList) error {
 		"gc_parallel_destroys",
 		"gc_max_allocs",
 		"no_host_uuid",
+		"server_join_info",
 	}
 	if err := helper.CheckHCLKeys(listVal, valid); err != nil {
 		return err
@@ -385,6 +386,7 @@ func parseClient(result **ClientConfig, list *ast.ObjectList) error {
 	delete(m, "chroot_env")
 	delete(m, "reserved")
 	delete(m, "stats")
+	delete(m, "server_join_info")
 
 	var config ClientConfig
 	dec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
@@ -448,6 +450,13 @@ func parseClient(result **ClientConfig, list *ast.ObjectList) error {
 		}
 	}
 
+	// Parse ServerJoin config
+	if o := listVal.Filter("server_join_info"); len(o.Items) > 0 {
+		if err := parseServerJoin(&config.ServerJoin, o); err != nil {
+			return multierror.Prefix(err, "server_join_info->")
+		}
+	}
+
 	*result = &config
 	return nil
 }
@@ -531,16 +540,20 @@ func parseServer(result **ServerConfig, list *ast.ObjectList) error {
 		"heartbeat_grace",
 		"min_heartbeat_ttl",
 		"max_heartbeats_per_second",
-		"start_join",
-		"retry_join",
-		"retry_max",
-		"retry_interval",
 		"rejoin_after_leave",
 		"encrypt",
 		"authoritative_region",
 		"non_voting_server",
 		"redundancy_zone",
 		"upgrade_version",
+
+		"server_join_info",
+
+		// For backwards compatibility
+		"start_join",
+		"retry_join",
+		"retry_max",
+		"retry_interval",
 	}
 	if err := helper.CheckHCLKeys(listVal, valid); err != nil {
 		return err
@@ -551,6 +564,8 @@ func parseServer(result **ServerConfig, list *ast.ObjectList) error {
 		return err
 	}
 
+	delete(m, "server_join_info")
+
 	var config ServerConfig
 	dec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
 		DecodeHook:       mapstructure.StringToTimeDurationHookFunc(),
@@ -570,10 +585,59 @@ func parseServer(result **ServerConfig, list *ast.ObjectList) error {
 		}
 	}
 
+	// Parse ServerJoin config
+	if o := listVal.Filter("server_join_info"); len(o.Items) > 0 {
+		if err := parseServerJoin(&config.ServerJoin, o); err != nil {
+			return multierror.Prefix(err, "server_join_info->")
+		}
+	}
+
 	*result = &config
 	return nil
 }
 
+func parseServerJoin(result **ServerJoin, list *ast.ObjectList) error {
+	list = list.Elem()
+	if len(list.Items) > 1 {
+		return fmt.Errorf("only one 'server_info_join' block allowed")
+	}
+
+	// Get our object
+	listVal := list.Items[0].Val
+
+	// Check for invalid keys
+	valid := []string{
+		"start_join",
+		"retry_join",
+		"retry_max",
+		"retry_interval",
+	}
+	if err := helper.CheckHCLKeys(listVal, valid); err != nil {
+		return err
+	}
+
+	var m map[string]interface{}
+	if err := hcl.DecodeObject(&m, listVal); err != nil {
+		return err
+	}
+
+	var serverJoinInfo ServerJoin
+	dec, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
+		DecodeHook:       mapstructure.StringToTimeDurationHookFunc(),
+		WeaklyTypedInput: true,
+		Result:           &serverJoinInfo,
+	})
+	if err != nil {
+		return err
+	}
+	if err := dec.Decode(m); err != nil {
+		return err
+	}
+
+	*result = &serverJoinInfo
+	return nil
+}
+
 func parseACL(result **ACLConfig, list *ast.ObjectList) error {
 	list = list.Elem()
 	if len(list.Items) > 1 {

command/agent/config_parse_test.go

@@ -47,6 +47,12 @@ func TestConfig_Parse(t *testing.T) {
 					AllocDir:  "/tmp/alloc",
 					Servers:   []string{"a.b.c:80", "127.0.0.1:1234"},
 					NodeClass: "linux-medium-64bit",
+					ServerJoin: &ServerJoin{
+						RetryJoin:        []string{"1.1.1.1", "2.2.2.2"},
+						StartJoin:        []string{"1.1.1.1", "2.2.2.2"},
+						RetryInterval:    "15s",
+						RetryMaxAttempts: 3,
+					},
 					Meta: map[string]string{
 						"foo": "bar",
 						"baz": "zip",
@@ -106,6 +112,12 @@ func TestConfig_Parse(t *testing.T) {
 					RedundancyZone:         "foo",
 					UpgradeVersion:         "0.8.0",
 					EncryptKey:             "abc",
+					ServerJoin: &ServerJoin{
+						RetryJoin:        []string{"1.1.1.1", "2.2.2.2"},
+						StartJoin:        []string{"1.1.1.1", "2.2.2.2"},
+						RetryInterval:    "15s",
+						RetryMaxAttempts: 3,
+					},
 				},
 				ACL: &ACLConfig{
 					Enabled:          true,

command/agent/retry_join.go

@@ -27,8 +27,17 @@ type DiscoverInterface interface {
 // retryJoiner is used to handle retrying a join until it succeeds or all of
 // its tries are exhausted.
 type retryJoiner struct {
-	// join adds the specified servers to the serf cluster
-	join func([]string) (int, error)
+	// serverJoin adds the specified servers to the serf cluster
+	serverJoin func([]string) (int, error)
+
+	// serverEnabled indicates whether the nomad agent will run in server mode
+	serverEnabled bool
+
+	// clientJoin adds the specified servers to the serf cluster
+	clientJoin func([]string) (int, error)
+
+	// clientEnabled indicates whether the nomad agent will run in client mode
+	clientEnabled bool
 
 	// discover is of type Discover, where this is either the go-discover
 	// implementation or a mock used for testing
@@ -44,21 +53,21 @@ type retryJoiner struct {
 
 // retryJoin is used to handle retrying a join until it succeeds or all retries
 // are exhausted.
-func (r *retryJoiner) RetryJoin(config *Config) {
-	if len(config.Server.RetryJoin) == 0 || !config.Server.Enabled {
+func (r *retryJoiner) RetryJoin(serverJoin *ServerJoin) {
+	if len(serverJoin.RetryJoin) == 0 {
 		return
 	}
 
 	attempt := 0
 
-	addrsToJoin := strings.Join(config.Server.RetryJoin, " ")
+	addrsToJoin := strings.Join(serverJoin.RetryJoin, " ")
 	r.logger.Printf("[INFO] agent: Joining cluster... %s", addrsToJoin)
 
 	for {
 		var addrs []string
 		var err error
 
-		for _, addr := range config.Server.RetryJoin {
+		for _, addr := range serverJoin.RetryJoin {
 			switch {
 			case strings.HasPrefix(addr, "provider="):
 				servers, err := r.discover.Addrs(addr, r.logger)
@@ -73,14 +82,24 @@ func (r *retryJoiner) RetryJoin(config *Config) {
 		}
 
 		if len(addrs) > 0 {
-			n, err := r.join(addrs)
+			if r.serverEnabled && r.serverJoin != nil {
+				n, err := r.serverJoin(addrs)
 				if err == nil {
 					r.logger.Printf("[INFO] agent: Join completed. Synced with %d initial agents", n)
+					return
+				}
+			}
+			if r.clientEnabled && r.clientJoin != nil {
+				n, err := r.clientJoin(addrs)
+				if err == nil {
+					r.logger.Printf("[INFO] agent: Join completed. Synced with %d initial agents", n)
+					return
+				}
 			}
 		}
 
 		attempt++
-		if config.Server.RetryMaxAttempts > 0 && attempt > config.Server.RetryMaxAttempts {
+		if serverJoin.RetryMaxAttempts > 0 && attempt > serverJoin.RetryMaxAttempts {
 			r.logger.Printf("[ERR] agent: max join retry exhausted, exiting")
 			close(r.errCh)
 			return
@@ -88,8 +107,8 @@ func (r *retryJoiner) RetryJoin(config *Config) {
 
 		if err != nil {
 			r.logger.Printf("[WARN] agent: Join failed: %v, retrying in %v", err,
-				config.Server.RetryInterval)
+				serverJoin.RetryInterval)
 		}
-		time.Sleep(config.Server.retryInterval)
+		time.Sleep(serverJoin.retryInterval)
 	}
 }

command/agent/retry_join_test.go

@@ -82,12 +82,9 @@ func TestRetryJoin_NonCloud(t *testing.T) {
 	t.Parallel()
 	require := require.New(t)
 
-	newConfig := &Config{
-		Server: &ServerConfig{
+	serverJoin := &ServerJoin{
 		RetryMaxAttempts: 1,
 		RetryJoin:        []string{"127.0.0.1"},
-			Enabled:          true,
-		},
 	}
 
 	var output []string
@@ -99,12 +96,13 @@ func TestRetryJoin_NonCloud(t *testing.T) {
 
 	joiner := retryJoiner{
 		discover:      &MockDiscover{},
-		join:     mockJoin,
+		serverJoin:    mockJoin,
+		serverEnabled: true,
 		logger:        log.New(ioutil.Discard, "", 0),
 		errCh:         make(chan struct{}),
 	}
 
-	joiner.RetryJoin(newConfig)
+	joiner.RetryJoin(serverJoin)
 
 	require.Equal(1, len(output))
 	require.Equal(stubAddress, output[0])
@@ -114,12 +112,9 @@ func TestRetryJoin_Cloud(t *testing.T) {
 	t.Parallel()
 	require := require.New(t)
 
-	newConfig := &Config{
-		Server: &ServerConfig{
+	serverJoin := &ServerJoin{
 		RetryMaxAttempts: 1,
 		RetryJoin:        []string{"provider=aws, tag_value=foo"},
-			Enabled:          true,
-		},
 	}
 
 	var output []string
@@ -132,12 +127,13 @@ func TestRetryJoin_Cloud(t *testing.T) {
 	mockDiscover := &MockDiscover{}
 	joiner := retryJoiner{
 		discover:      mockDiscover,
-		join:     mockJoin,
+		serverJoin:    mockJoin,
+		serverEnabled: true,
 		logger:        log.New(ioutil.Discard, "", 0),
 		errCh:         make(chan struct{}),
 	}
 
-	joiner.RetryJoin(newConfig)
+	joiner.RetryJoin(serverJoin)
 
 	require.Equal(1, len(output))
 	require.Equal("provider=aws, tag_value=foo", mockDiscover.ReceivedAddrs)
@@ -148,12 +144,9 @@ func TestRetryJoin_MixedProvider(t *testing.T) {
 	t.Parallel()
 	require := require.New(t)
 
-	newConfig := &Config{
-		Server: &ServerConfig{
+	serverJoin := &ServerJoin{
 		RetryMaxAttempts: 1,
 		RetryJoin:        []string{"provider=aws, tag_value=foo", "127.0.0.1"},
-			Enabled:          true,
-		},
 	}
 
 	var output []string
@@ -166,14 +159,45 @@ func TestRetryJoin_MixedProvider(t *testing.T) {
 	mockDiscover := &MockDiscover{}
 	joiner := retryJoiner{
 		discover:      mockDiscover,
-		join:     mockJoin,
+		serverJoin:    mockJoin,
+		serverEnabled: true,
 		logger:        log.New(ioutil.Discard, "", 0),
 		errCh:         make(chan struct{}),
 	}
 
-	joiner.RetryJoin(newConfig)
+	joiner.RetryJoin(serverJoin)
 
 	require.Equal(2, len(output))
 	require.Equal("provider=aws, tag_value=foo", mockDiscover.ReceivedAddrs)
 	require.Equal(stubAddress, output[0])
 }
+
+func TestRetryJoin_Client(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+
+	serverJoin := &ServerJoin{
+		RetryMaxAttempts: 1,
+		RetryJoin:        []string{"127.0.0.1"},
+	}
+
+	var output []string
+
+	mockJoin := func(s []string) (int, error) {
+		output = s
+		return 0, nil
+	}
+
+	joiner := retryJoiner{
+		discover:      &MockDiscover{},
+		clientJoin:    mockJoin,
+		clientEnabled: true,
+		logger:        log.New(ioutil.Discard, "", 0),
+		errCh:         make(chan struct{}),
+	}
+
+	joiner.RetryJoin(serverJoin)
+
+	require.Equal(1, len(output))
+	require.Equal(stubAddress, output[0])
+}