consul: dev mode works

command/agent/agent.go

@@ -124,7 +124,7 @@ func Create(config *Config, logOutput io.Writer) (*Agent, error) {
 	if config.Datacenter == "" {
 		return nil, fmt.Errorf("Must configure a Datacenter")
 	}
-	if config.DataDir == "" {
+	if config.DataDir == "" && !config.DevMode {
 		return nil, fmt.Errorf("Must configure a DataDir")
 	}
 
@@ -227,6 +227,9 @@ func (a *Agent) consulConfig() *consul.Config {
 		base = consul.DefaultConfig()
 	}
 
+	// Apply dev mode
+	base.DevMode = a.config.DevMode
+
 	// Override with our config
 	if a.config.Datacenter != "" {
 		base.Datacenter = a.config.Datacenter
@@ -748,7 +751,7 @@ func (a *Agent) AddService(service *structs.NodeService, chkTypes CheckTypes, pe
 	a.state.AddService(service, token)
 
 	// Persist the service to a file
-	if persist {
+	if persist && !a.config.DevMode {
 		if err := a.persistService(service); err != nil {
 			return err
 		}
@@ -958,7 +961,7 @@ func (a *Agent) AddCheck(check *structs.HealthCheck, chkType *CheckType, persist
 	a.state.AddCheck(check, token)
 
 	// Persist the check
-	if persist {
+	if persist && !a.config.DevMode {
 		return a.persistCheck(check, chkType)
 	}
 
@@ -1022,6 +1025,10 @@ func (a *Agent) UpdateCheck(checkID, status, output string) error {
 	// Set the status through CheckTTL to reset the TTL
 	check.SetStatus(status, output)
 
+	if a.config.DevMode {
+		return nil
+	}
+
 	// Always persist the state for TTL checks
 	if err := a.persistCheckState(check, status, output); err != nil {
 		return fmt.Errorf("failed persisting state for check %q: %s", checkID, err)

command/agent/command.go

@@ -60,12 +60,14 @@ func (c *Command) readConfig() *Config {
 	var retryInterval string
 	var retryIntervalWan string
 	var dnsRecursors []string
+	var dev bool
 	cmdFlags := flag.NewFlagSet("agent", flag.ContinueOnError)
 	cmdFlags.Usage = func() { c.Ui.Output(c.Help()) }
 
 	cmdFlags.Var((*AppendSliceValue)(&configFiles), "config-file", "json file to read config from")
 	cmdFlags.Var((*AppendSliceValue)(&configFiles), "config-dir", "directory of json files to read")
 	cmdFlags.Var((*AppendSliceValue)(&dnsRecursors), "recursor", "address of an upstream DNS server")
+	cmdFlags.BoolVar(&dev, "dev", false, "development server mode")
 
 	cmdFlags.StringVar(&cmdConfig.LogLevel, "log-level", "", "log level")
 	cmdFlags.StringVar(&cmdConfig.NodeName, "node", "", "node name")
@@ -137,7 +139,13 @@ func (c *Command) readConfig() *Config {
 		cmdConfig.RetryIntervalWan = dur
 	}
 
-	config := DefaultConfig()
+	var config *Config
+	if dev {
+		config = DevConfig()
+	} else {
+		config = DefaultConfig()
+	}
+
 	if len(configFiles) > 0 {
 		fileConfig, err := ReadConfigPaths(configFiles)
 		if err != nil {
@@ -162,7 +170,7 @@ func (c *Command) readConfig() *Config {
 	}
 
 	// Ensure we have a data directory
-	if config.DataDir == "" {
+	if config.DataDir == "" && !dev {
 		c.Ui.Error("Must specify data directory using -data-dir")
 		return nil
 	}

command/agent/config.go

@@ -94,6 +94,10 @@ type DNSConfig struct {
 // Some of this is configurable as CLI flags, but most must
 // be set using a configuration file.
 type Config struct {
+	// DevMode enables a fast-path mode of opertaion to bring up an in-memory
+	// server with minimal configuration. Useful for developing Consul.
+	DevMode bool `mapstructure:"-"`
+
 	// Bootstrap is used to bring up the first Consul server, and
 	// permits that node to elect itself leader
 	Bootstrap bool `mapstructure:"bootstrap"`
@@ -521,6 +525,17 @@ func DefaultConfig() *Config {
 	}
 }
 
+// DevConfig is used to return a set of configuration to use for dev mode.
+func DevConfig() *Config {
+	conf := DefaultConfig()
+	conf.DevMode = true
+	conf.LogLevel = "DEBUG"
+	conf.Server = true
+	conf.EnableDebug = true
+	conf.DisableAnonymousSignature = true
+	return conf
+}
+
 // EncryptBytes returns the encryption key configured.
 func (c *Config) EncryptBytes() ([]byte, error) {
 	return base64.StdEncoding.DecodeString(c.EncryptKey)

consul/config.go

@@ -54,6 +54,9 @@ type Config struct {
 	// DataDir is the directory to store our state in
 	DataDir string
 
+	// DevMode is used to enable a development server mode.
+	DevMode bool
+
 	// Node name is the name we use to advertise. Defaults to hostname.
 	NodeName string
 

consul/server.go

@@ -110,6 +110,7 @@ type Server struct {
 	raftPeers     raft.PeerStore
 	raftStore     *raftboltdb.BoltStore
 	raftTransport *raft.NetworkTransport
+	raftInmem     *raft.InmemStore
 
 	// reconcileCh is used to pass events from the serf handler
 	// into the leader manager, so that the strong state can be
@@ -173,7 +174,7 @@ func NewServer(config *Config) (*Server, error) {
 	}
 
 	// Check for a data directory!
-	if config.DataDir == "" {
+	if config.DataDir == "" && !config.DevMode {
 		return nil, fmt.Errorf("Config must provide a DataDir")
 	}
 
@@ -327,7 +328,7 @@ func (s *Server) setupSerf(conf *serf.Config, ch chan serf.Event, path string, w
 // setupRaft is used to setup and initialize Raft
 func (s *Server) setupRaft() error {
 	// If we are in bootstrap mode, enable a single node cluster
-	if s.config.Bootstrap {
+	if s.config.Bootstrap || s.config.DevMode {
 		s.config.RaftConfig.EnableSingleNode = true
 	}
 
@@ -338,45 +339,66 @@ func (s *Server) setupRaft() error {
 		return err
 	}
 
-	// Create the base raft path
-	path := filepath.Join(s.config.DataDir, raftState)
-	if err := ensurePath(path, true); err != nil {
-		return err
-	}
-
-	// Create the backend raft store for logs and stable storage
-	store, err := raftboltdb.NewBoltStore(filepath.Join(path, "raft.db"))
-	if err != nil {
-		return err
-	}
-	s.raftStore = store
-
-	// Wrap the store in a LogCache to improve performance
-	cacheStore, err := raft.NewLogCache(raftLogCacheSize, store)
-	if err != nil {
-		store.Close()
-		return err
-	}
-
-	// Create the snapshot store
-	snapshots, err := raft.NewFileSnapshotStore(path, snapshotsRetained, s.config.LogOutput)
-	if err != nil {
-		store.Close()
-		return err
-	}
-
 	// Create a transport layer
 	trans := raft.NewNetworkTransport(s.raftLayer, 3, 10*time.Second, s.config.LogOutput)
 	s.raftTransport = trans
 
-	// Setup the peer store
-	s.raftPeers = raft.NewJSONPeers(path, trans)
+	var log raft.LogStore
+	var stable raft.StableStore
+	var snap raft.SnapshotStore
+	var peers raft.PeerStore
+
+	if s.config.DevMode {
+		store := raft.NewInmemStore()
+		s.raftInmem = store
+		stable = store
+		log = store
+		snap = raft.NewDiscardSnapshotStore()
+		peers = &raft.StaticPeers{}
+		s.raftPeers = peers
+	} else {
+		// Create the base raft path
+		path := filepath.Join(s.config.DataDir, raftState)
+		if err := ensurePath(path, true); err != nil {
+			return err
+		}
+
+		// Create the backend raft store for logs and stable storage
+		store, err := raftboltdb.NewBoltStore(filepath.Join(path, "raft.db"))
+		if err != nil {
+			return err
+		}
+		s.raftStore = store
+		stable = store
+
+		// Wrap the store in a LogCache to improve performance
+		cacheStore, err := raft.NewLogCache(raftLogCacheSize, store)
+		if err != nil {
+			store.Close()
+			return err
+		}
+		log = cacheStore
+
+		// Create the snapshot store
+		snapshots, err := raft.NewFileSnapshotStore(path, snapshotsRetained, s.config.LogOutput)
+		if err != nil {
+			store.Close()
+			return err
+		}
+		snap = snapshots
+
+		// Setup the peer store
+		s.raftPeers = raft.NewJSONPeers(path, trans)
+		peers = s.raftPeers
+	}
 
 	// Ensure local host is always included if we are in bootstrap mode
 	if s.config.Bootstrap {
 		peers, err := s.raftPeers.Peers()
 		if err != nil {
-			store.Close()
+			if s.raftStore != nil {
+				s.raftStore.Close()
+			}
 			return err
 		}
 		if !raft.PeerContained(peers, trans.LocalAddr()) {
@@ -388,10 +410,10 @@ func (s *Server) setupRaft() error {
 	s.config.RaftConfig.LogOutput = s.config.LogOutput
 
 	// Setup the Raft store
-	s.raft, err = raft.NewRaft(s.config.RaftConfig, s.fsm, cacheStore, store,
-		snapshots, s.raftPeers, trans)
+	s.raft, err = raft.NewRaft(s.config.RaftConfig, s.fsm, log, stable,
+		snap, s.raftPeers, trans)
 	if err != nil {
-		store.Close()
+		s.raftStore.Close()
 		trans.Close()
 		return err
 	}
@@ -484,7 +506,9 @@ func (s *Server) Shutdown() error {
 		if err := future.Error(); err != nil {
 			s.logger.Printf("[WARN] consul: Error shutting down raft: %s", err)
 		}
-		s.raftStore.Close()
+		if s.raftStore != nil {
+			s.raftStore.Close()
+		}
 
 		// Clear the peer set on a graceful leave to avoid
 		// triggering elections on a rejoin.