Config clean up and usage messaging.

etcd.go

@@ -17,12 +17,8 @@ limitations under the License.
 package main
 
 import (
-	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
-	"os/signal"
-	"runtime/pprof"
 
 	"github.com/coreos/etcd/log"
 	"github.com/coreos/etcd/server"
@@ -31,21 +27,30 @@ import (
 )
 
 func main() {
-	parseFlags()
-
 	// Load configuration.
 	var config = server.NewConfig()
 	if err := config.Load(os.Args[1:]); err != nil {
-		log.Fatal("Configuration error:", err)
+		fmt.Println(server.Usage() + "\n")
+		fmt.Println(err.Error() + "\n")
+		os.Exit(1)
+	} else if config.ShowVersion {
+		fmt.Println(server.ReleaseVersion)
+		os.Exit(0)
+	} else if config.ShowHelp {
+		fmt.Println(server.Usage() + "\n")
+		os.Exit(0)
 	}
 
-	// Turn on logging.
+	// Enable options.
 	if config.VeryVerbose {
 		log.Verbose = true
 		raft.SetLogLevel(raft.Debug)
 	} else if config.Verbose {
 		log.Verbose = true
 	}
+	if config.CPUProfileFile != "" {
+		profile(config.CPUProfileFile)
+	}
 
 	// Setup a default directory based on the machine name
 	if config.DataDir == "" {
@@ -116,39 +121,3 @@ func main() {
 	}()
 	log.Fatal(s.ListenAndServe())
 }
-
-// Parses non-configuration flags.
-func parseFlags() {
-	var versionFlag bool
-	var cpuprofile string
-
-	f := flag.NewFlagSet(os.Args[0], -1)
-	f.SetOutput(ioutil.Discard)
-	f.BoolVar(&versionFlag, "version", false, "print the version and exit")
-	f.StringVar(&cpuprofile, "cpuprofile", "", "write cpu profile to file")
-	f.Parse(os.Args[1:])
-
-	// Print version if necessary.
-	if versionFlag {
-		fmt.Println(server.ReleaseVersion)
-		os.Exit(0)
-	}
-
-	// Begin CPU profiling if specified.
-	if cpuprofile != "" {
-		f, err := os.Create(cpuprofile)
-		if err != nil {
-			log.Fatal(err)
-		}
-		pprof.StartCPUProfile(f)
-
-		c := make(chan os.Signal, 1)
-		signal.Notify(c, os.Interrupt)
-		go func() {
-			sig := <-c
-			log.Infof("captured %v, stopping profiler and exiting..", sig)
-			pprof.StopCPUProfile()
-			os.Exit(1)
-		}()
-	}
-}

profile.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"os"
+	"os/signal"
+	"runtime/pprof"
+
+	"github.com/coreos/etcd/log"
+)
+
+// profile starts CPU profiling.
+func profile(path string) {
+	f, err := os.Create(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+	pprof.StartCPUProfile(f)
+
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	go func() {
+		sig := <-c
+		log.Infof("captured %v, stopping profiler and exiting..", sig)
+		pprof.StopCPUProfile()
+		os.Exit(1)
+	}()
+}

server/config.go

@@ -21,23 +21,23 @@ const DefaultSystemConfigPath = "/etc/etcd/etcd.conf"
 
 // A lookup of deprecated flags to their new flag name.
 var newFlagNameLookup = map[string]string{
-	"C": "peers",
-	"CF": "peers-file",
-	"n": "name",
-	"c": "addr",
-	"cl": "bind-addr",
-	"s": "peer-addr",
-	"sl": "peer-bind-addr",
-	"d": "data-dir",
-	"m": "max-result-buffer",
-	"r": "max-retry-attempts",
-	"maxsize": "max-cluster-size",
-	"clientCAFile": "ca-file",
-	"clientCert": "cert-file",
-	"clientKey": "key-file",
-	"serverCAFile": "peer-ca-file",
-	"serverCert": "peer-cert-file",
-	"serverKey": "peer-key-file",
+	"C":             "peers",
+	"CF":            "peers-file",
+	"n":             "name",
+	"c":             "addr",
+	"cl":            "bind-addr",
+	"s":             "peer-addr",
+	"sl":            "peer-bind-addr",
+	"d":             "data-dir",
+	"m":             "max-result-buffer",
+	"r":             "max-retry-attempts",
+	"maxsize":       "max-cluster-size",
+	"clientCAFile":  "ca-file",
+	"clientCert":    "cert-file",
+	"clientKey":     "key-file",
+	"serverCAFile":  "peer-ca-file",
+	"serverCert":    "peer-cert-file",
+	"serverKey":     "peer-key-file",
 	"snapshotCount": "snapshot-count",
 }
 
@@ -45,10 +45,11 @@ var newFlagNameLookup = map[string]string{
 type Config struct {
 	SystemPath string
 
-	Addr             string   `toml:"addr" env:"ETCD_ADDR"`
-	BindAddr         string   `toml:"bind_addr" env:"ETCD_BIND_ADDR"`
-	CAFile           string   `toml:"ca_file" env:"ETCD_CA_FILE"`
-	CertFile         string   `toml:"cert_file" env:"ETCD_CERT_FILE"`
+	Addr             string `toml:"addr" env:"ETCD_ADDR"`
+	BindAddr         string `toml:"bind_addr" env:"ETCD_BIND_ADDR"`
+	CAFile           string `toml:"ca_file" env:"ETCD_CA_FILE"`
+	CertFile         string `toml:"cert_file" env:"ETCD_CERT_FILE"`
+	CPUProfileFile   string
 	CorsOrigins      []string `toml:"cors" env:"ETCD_CORS"`
 	DataDir          string   `toml:"data_dir" env:"ETCD_DATA_DIR"`
 	Force            bool
@@ -61,8 +62,10 @@ type Config struct {
 	Name             string   `toml:"name" env:"ETCD_NAME"`
 	Snapshot         bool     `toml:"snapshot" env:"ETCD_SNAPSHOT"`
 	SnapshotCount    int      `toml:"snapshot_count" env:"ETCD_SNAPSHOTCOUNT"`
-	Verbose          bool     `toml:"verbose" env:"ETCD_VERBOSE"`
-	VeryVerbose      bool     `toml:"very_verbose" env:"ETCD_VERY_VERBOSE"`
+	ShowHelp         bool
+	ShowVersion      bool
+	Verbose          bool `toml:"verbose" env:"ETCD_VERBOSE"`
+	VeryVerbose      bool `toml:"very_verbose" env:"ETCD_VERY_VERBOSE"`
 
 	Peer struct {
 		Addr     string `toml:"addr" env:"ETCD_PEER_ADDR"`
@@ -117,15 +120,6 @@ func (c *Config) Load(arguments []string) error {
 		return err
 	}
 
-	// Load from command line flags (deprecated).
-	if err := c.LoadDeprecatedFlags(arguments); err != nil {
-		if err, ok := err.(*DeprecationError); ok {
-			fmt.Fprintln(os.Stderr, err.Error())
-		} else {
-			return err
-		}
-	}
-
 	// Loads peers if a peer file was specified.
 	if err := c.LoadPeersFile(); err != nil {
 		return err
@@ -133,7 +127,7 @@ func (c *Config) Load(arguments []string) error {
 
 	// Sanitize all the input fields.
 	if err := c.Sanitize(); err != nil {
-		return fmt.Errorf("sanitize:", err)
+		return fmt.Errorf("sanitize: %v", err)
 	}
 
 	return nil
@@ -195,100 +189,85 @@ func (c *Config) loadEnv(target interface{}) error {
 	return nil
 }
 
-// Loads deprecated configuration settings from the command line.
-func (c *Config) LoadDeprecatedFlags(arguments []string) error {
-	var peers string
-
-	f := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
-	f.SetOutput(ioutil.Discard)
-
-	f.StringVar(&peers, "C", "", "(deprecated)")
-	f.StringVar(&c.PeersFile, "CF", c.PeersFile, "(deprecated)")
-
-	f.StringVar(&c.Name, "n", c.Name, "(deprecated)")
-	f.StringVar(&c.Addr, "c", c.Addr, "(deprecated)")
-	f.StringVar(&c.BindAddr, "cl", c.BindAddr, "the listening hostname for etcd client communication (defaults to advertised ip)")
-	f.StringVar(&c.Peer.Addr, "s", c.Peer.Addr, "the advertised public hostname:port for raft server communication")
-	f.StringVar(&c.Peer.BindAddr, "sl", c.Peer.BindAddr, "the listening hostname for raft server communication (defaults to advertised ip)")
-
-	f.StringVar(&c.Peer.CAFile, "serverCAFile", c.Peer.CAFile, "the path of the CAFile")
-	f.StringVar(&c.Peer.CertFile, "serverCert", c.Peer.CertFile, "the cert file of the server")
-	f.StringVar(&c.Peer.KeyFile, "serverKey", c.Peer.KeyFile, "the key file of the server")
-
-	f.StringVar(&c.CAFile, "clientCAFile", c.CAFile, "the path of the client CAFile")
-	f.StringVar(&c.CertFile, "clientCert", c.CertFile, "the cert file of the client")
-	f.StringVar(&c.KeyFile, "clientKey", c.KeyFile, "the key file of the client")
-
-	f.StringVar(&c.DataDir, "d", c.DataDir, "the directory to store log and snapshot")
-	f.IntVar(&c.MaxResultBuffer, "m", c.MaxResultBuffer, "the max size of result buffer")
-	f.IntVar(&c.MaxRetryAttempts, "r", c.MaxRetryAttempts, "the max retry attempts when trying to join a cluster")
-	f.IntVar(&c.MaxClusterSize, "maxsize", c.MaxClusterSize, "the max size of the cluster")
-
-	f.IntVar(&c.SnapshotCount, "snapshotCount", c.SnapshotCount, "save the in-memory logs and states to a snapshot file a given number of transactions")
-
-	f.Parse(arguments)
-
-	// Convert some parameters to lists.
-	if peers != "" {
-		c.Peers = trimsplit(peers, ",")
-	}
-
-	// Generate deprecation warning.
-	warnings := make([]string, 0)
-	f.Visit(func(f *flag.Flag) {
-		warnings = append(warnings, fmt.Sprintf("[deprecated] use -%s, not -%s", newFlagNameLookup[f.Name], f.Name))
-	})
-	if len(warnings) > 0 {
-		return &DeprecationError{strings.Join(warnings, "\n")}
-	}
-
-	return nil
-}
-
 // Loads configuration from command line flags.
 func (c *Config) LoadFlags(arguments []string) error {
-	var peers, cors string
+	var peers, cors, path string
 
 	f := flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
 	f.SetOutput(ioutil.Discard)
 
-	f.BoolVar(&c.Force, "f", false, "force new node configuration if existing is found (WARNING: data loss!)")
-	f.BoolVar(&c.Force, "force", false, "force new node configuration if existing is found (WARNING: data loss!)")
+	f.BoolVar(&c.ShowHelp, "h", false, "")
+	f.BoolVar(&c.ShowHelp, "help", false, "")
+	f.BoolVar(&c.ShowVersion, "version", false, "")
 
-	f.BoolVar(&c.Verbose, "v", c.Verbose, "verbose logging")
-	f.BoolVar(&c.VeryVerbose, "vv", c.Verbose, "very verbose logging")
+	f.BoolVar(&c.Force, "f", false, "")
+	f.BoolVar(&c.Force, "force", false, "")
 
-	f.StringVar(&peers, "peers", "", "the ip address and port of a existing peers in the cluster, sepearate by comma")
-	f.StringVar(&c.PeersFile, "peers-file", c.PeersFile, "the file contains a list of existing peers in the cluster, seperate by comma")
+	f.BoolVar(&c.Verbose, "v", c.Verbose, "")
+	f.BoolVar(&c.VeryVerbose, "vv", c.Verbose, "")
 
-	f.StringVar(&c.Name, "name", c.Name, "the node name (required)")
-	f.StringVar(&c.Addr, "addr", c.Addr, "the advertised public hostname:port for etcd client communication")
-	f.StringVar(&c.BindAddr, "bind-addr", c.BindAddr, "the listening hostname for etcd client communication (defaults to advertised ip)")
-	f.StringVar(&c.Peer.Addr, "peer-addr", c.Peer.Addr, "the advertised public hostname:port for raft server communication")
-	f.StringVar(&c.Peer.BindAddr, "peer-bind-addr", c.Peer.BindAddr, "the listening hostname for raft server communication (defaults to advertised ip)")
+	f.StringVar(&peers, "peers", "", "")
+	f.StringVar(&c.PeersFile, "peers-file", c.PeersFile, "")
 
-	f.StringVar(&c.Peer.CAFile, "peer-ca-file", c.Peer.CAFile, "the path of the CAFile")
-	f.StringVar(&c.Peer.CertFile, "peer-cert-file", c.Peer.CertFile, "the cert file of the server")
-	f.StringVar(&c.Peer.KeyFile, "peer-key-file", c.Peer.KeyFile, "the key file of the server")
+	f.StringVar(&c.Name, "name", c.Name, "")
+	f.StringVar(&c.Addr, "addr", c.Addr, "")
+	f.StringVar(&c.BindAddr, "bind-addr", c.BindAddr, "")
+	f.StringVar(&c.Peer.Addr, "peer-addr", c.Peer.Addr, "")
+	f.StringVar(&c.Peer.BindAddr, "peer-bind-addr", c.Peer.BindAddr, "")
 
-	f.StringVar(&c.CAFile, "ca-file", c.CAFile, "the path of the client CAFile")
-	f.StringVar(&c.CertFile, "cert-file", c.CertFile, "the cert file of the client")
-	f.StringVar(&c.KeyFile, "key-file", c.KeyFile, "the key file of the client")
+	f.StringVar(&c.CAFile, "ca-file", c.CAFile, "")
+	f.StringVar(&c.CertFile, "cert-file", c.CertFile, "")
+	f.StringVar(&c.KeyFile, "key-file", c.KeyFile, "")
 
-	f.StringVar(&c.DataDir, "data-dir", c.DataDir, "the directory to store log and snapshot")
-	f.IntVar(&c.MaxResultBuffer, "max-result-buffer", c.MaxResultBuffer, "the max size of result buffer")
-	f.IntVar(&c.MaxRetryAttempts, "max-retry-attempts", c.MaxRetryAttempts, "the max retry attempts when trying to join a cluster")
-	f.IntVar(&c.MaxClusterSize, "max-cluster-size", c.MaxClusterSize, "the max size of the cluster")
-	f.StringVar(&cors, "cors", "", "whitelist origins for cross-origin resource sharing (e.g. '*' or 'http://localhost:8001,etc')")
+	f.StringVar(&c.Peer.CAFile, "peer-ca-file", c.Peer.CAFile, "")
+	f.StringVar(&c.Peer.CertFile, "peer-cert-file", c.Peer.CertFile, "")
+	f.StringVar(&c.Peer.KeyFile, "peer-key-file", c.Peer.KeyFile, "")
 
-	f.BoolVar(&c.Snapshot, "snapshot", c.Snapshot, "open or close snapshot")
-	f.IntVar(&c.SnapshotCount, "snapshot-count", c.SnapshotCount, "save the in-memory logs and states to a snapshot file a given number of transactions")
+	f.StringVar(&c.DataDir, "data-dir", c.DataDir, "")
+	f.IntVar(&c.MaxResultBuffer, "max-result-buffer", c.MaxResultBuffer, "")
+	f.IntVar(&c.MaxRetryAttempts, "max-retry-attempts", c.MaxRetryAttempts, "")
+	f.IntVar(&c.MaxClusterSize, "max-cluster-size", c.MaxClusterSize, "")
+	f.StringVar(&cors, "cors", "", "")
 
-	// These flags are ignored since they were already parsed.
-	var path string
-	f.StringVar(&path, "config", "", "path to config file")
+	f.BoolVar(&c.Snapshot, "snapshot", c.Snapshot, "")
+	f.IntVar(&c.SnapshotCount, "snapshot-count", c.SnapshotCount, "")
+	f.StringVar(&c.CPUProfileFile, "cpuprofile", "", "")
 
-	f.Parse(arguments)
+	// BEGIN IGNORED FLAGS
+	f.StringVar(&path, "config", "", "")
+	// BEGIN IGNORED FLAGS
+
+	// BEGIN DEPRECATED FLAGS
+	f.StringVar(&peers, "C", "", "(deprecated)")
+	f.StringVar(&c.PeersFile, "CF", c.PeersFile, "(deprecated)")
+	f.StringVar(&c.Name, "n", c.Name, "(deprecated)")
+	f.StringVar(&c.Addr, "c", c.Addr, "(deprecated)")
+	f.StringVar(&c.BindAddr, "cl", c.BindAddr, "(deprecated)")
+	f.StringVar(&c.Peer.Addr, "s", c.Peer.Addr, "(deprecated)")
+	f.StringVar(&c.Peer.BindAddr, "sl", c.Peer.BindAddr, "(deprecated)")
+	f.StringVar(&c.Peer.CAFile, "serverCAFile", c.Peer.CAFile, "(deprecated)")
+	f.StringVar(&c.Peer.CertFile, "serverCert", c.Peer.CertFile, "(deprecated)")
+	f.StringVar(&c.Peer.KeyFile, "serverKey", c.Peer.KeyFile, "(deprecated)")
+	f.StringVar(&c.CAFile, "clientCAFile", c.CAFile, "(deprecated)")
+	f.StringVar(&c.CertFile, "clientCert", c.CertFile, "(deprecated)")
+	f.StringVar(&c.KeyFile, "clientKey", c.KeyFile, "(deprecated)")
+	f.StringVar(&c.DataDir, "d", c.DataDir, "(deprecated)")
+	f.IntVar(&c.MaxResultBuffer, "m", c.MaxResultBuffer, "(deprecated)")
+	f.IntVar(&c.MaxRetryAttempts, "r", c.MaxRetryAttempts, "(deprecated)")
+	f.IntVar(&c.MaxClusterSize, "maxsize", c.MaxClusterSize, "(deprecated)")
+	f.IntVar(&c.SnapshotCount, "snapshotCount", c.SnapshotCount, "(deprecated)")
+	// END DEPRECATED FLAGS
+
+	if err := f.Parse(arguments); err != nil {
+		return err
+	}
+
+	// Print deprecation warnings on STDERR.
+	f.Visit(func(f *flag.Flag) {
+		if len(newFlagNameLookup[f.Name]) > 0 {
+			fmt.Fprintf(os.Stderr, "[deprecated] use -%s, not -%s", newFlagNameLookup[f.Name], f.Name)
+		}
+	})
 
 	// Convert some parameters to lists.
 	if peers != "" {
@@ -479,15 +458,3 @@ func sanitizeBindAddr(bindAddr string, addr string) (string, error) {
 
 	return net.JoinHostPort(bindAddr, aport), nil
 }
-
-
-// DeprecationError is a warning for CLI users that one or more arguments will
-// not be supported in future released.
-type DeprecationError struct {
-	s string
-}
-
-func (e *DeprecationError) Error() string {
-	return e.s
-}
-

server/config_test.go

@@ -93,7 +93,7 @@ func TestConfigEnv(t *testing.T) {
 	c.LoadEnv()
 	assert.Equal(t, c.CAFile, "/tmp/file.ca", "")
 	assert.Equal(t, c.CertFile, "/tmp/file.cert", "")
-	assert.Equal(t, c.CorsOrigins, []string{"localhost:4001", "localhost:4002"}, "") 
+	assert.Equal(t, c.CorsOrigins, []string{"localhost:4001", "localhost:4002"}, "")
 	assert.Equal(t, c.DataDir, "/tmp/data", "")
 	assert.Equal(t, c.KeyFile, "/tmp/file.key", "")
 	assert.Equal(t, c.BindAddr, "127.0.0.1:4003", "")
@@ -113,6 +113,27 @@ func TestConfigEnv(t *testing.T) {
 	assert.Equal(t, c.Peer.BindAddr, "127.0.0.1:7003", "")
 }
 
+// Ensures that the "help" flag can be parsed.
+func TestConfigHelpFlag(t *testing.T) {
+	c := NewConfig()
+	assert.Nil(t, c.LoadFlags([]string{"-help"}), "")
+	assert.True(t, c.ShowHelp)
+}
+
+// Ensures that the abbreviated "help" flag can be parsed.
+func TestConfigAbbreviatedHelpFlag(t *testing.T) {
+	c := NewConfig()
+	assert.Nil(t, c.LoadFlags([]string{"-h"}), "")
+	assert.True(t, c.ShowHelp)
+}
+
+// Ensures that the "version" flag can be parsed.
+func TestConfigVersionFlag(t *testing.T) {
+	c := NewConfig()
+	assert.Nil(t, c.LoadFlags([]string{"-version"}), "")
+	assert.True(t, c.ShowVersion)
+}
+
 // Ensures that the "force config" flag can be parsed.
 func TestConfigForceFlag(t *testing.T) {
 	c := NewConfig()
@@ -405,6 +426,14 @@ func TestConfigPeerBindAddrEnv(t *testing.T) {
 	})
 }
 
+// Ensures that a bad flag returns an error.
+func TestConfigBadFlag(t *testing.T) {
+	c := NewConfig()
+	err := c.LoadFlags([]string{"-no-such-flag"})
+	assert.Error(t, err)
+	assert.Equal(t, err.Error(), `flag provided but not defined: -no-such-flag`)
+}
+
 // Ensures that a the Peer Listen Host file flag can be parsed.
 func TestConfigPeerBindAddrFlag(t *testing.T) {
 	c := NewConfig()
@@ -456,118 +485,165 @@ func TestConfigCLIArgsOverrideEnvVar(t *testing.T) {
 //--------------------------------------
 
 func TestConfigDeprecatedAddrFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-c", "127.0.0.1:4002"})
-	assert.Equal(t, err.Error(), "[deprecated] use -addr, not -c", "")
-	assert.Equal(t, c.Addr, "127.0.0.1:4002", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-c", "127.0.0.1:4002"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Addr, "127.0.0.1:4002")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -addr, not -c")
 }
 
 func TestConfigDeprecatedBindAddrFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-cl", "127.0.0.1:4003"})
-	assert.Equal(t, err.Error(), "[deprecated] use -bind-addr, not -cl", "")
-	assert.Equal(t, c.BindAddr, "127.0.0.1:4003", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-cl", "127.0.0.1:4003"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.BindAddr, "127.0.0.1:4003", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -bind-addr, not -cl", "")
 }
 
 func TestConfigDeprecatedCAFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-clientCAFile", "/tmp/file.ca"})
-	assert.Equal(t, err.Error(), "[deprecated] use -ca-file, not -clientCAFile", "")
-	assert.Equal(t, c.CAFile, "/tmp/file.ca", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-clientCAFile", "/tmp/file.ca"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.CAFile, "/tmp/file.ca", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -ca-file, not -clientCAFile", "")
 }
 
 func TestConfigDeprecatedCertFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-clientCert", "/tmp/file.cert"})
-	assert.Equal(t, err.Error(), "[deprecated] use -cert-file, not -clientCert", "")
-	assert.Equal(t, c.CertFile, "/tmp/file.cert", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-clientCert", "/tmp/file.cert"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.CertFile, "/tmp/file.cert", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -cert-file, not -clientCert", "")
 }
 
 func TestConfigDeprecatedKeyFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-clientKey", "/tmp/file.key"})
-	assert.Equal(t, err.Error(), "[deprecated] use -key-file, not -clientKey", "")
-	assert.Equal(t, c.KeyFile, "/tmp/file.key", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-clientKey", "/tmp/file.key"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.KeyFile, "/tmp/file.key", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -key-file, not -clientKey", "")
 }
 
 func TestConfigDeprecatedPeersFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-C", "coreos.com:4001,coreos.com:4002"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peers, not -C", "")
-	assert.Equal(t, c.Peers, []string{"coreos.com:4001", "coreos.com:4002"}, "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-C", "coreos.com:4001,coreos.com:4002"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Peers, []string{"coreos.com:4001", "coreos.com:4002"}, "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peers, not -C", "")
 }
 
 func TestConfigDeprecatedPeersFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-CF", "/tmp/machines"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peers-file, not -CF", "")
-	assert.Equal(t, c.PeersFile, "/tmp/machines", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-CF", "/tmp/machines"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.PeersFile, "/tmp/machines", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peers-file, not -CF", "")
 }
 
 func TestConfigDeprecatedMaxClusterSizeFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-maxsize", "5"})
-	assert.Equal(t, err.Error(), "[deprecated] use -max-cluster-size, not -maxsize", "")
-	assert.Equal(t, c.MaxClusterSize, 5, "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-maxsize", "5"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.MaxClusterSize, 5, "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -max-cluster-size, not -maxsize", "")
 }
 
 func TestConfigDeprecatedMaxResultBufferFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-m", "512"})
-	assert.Equal(t, err.Error(), "[deprecated] use -max-result-buffer, not -m", "")
-	assert.Equal(t, c.MaxResultBuffer, 512, "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-m", "512"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.MaxResultBuffer, 512, "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -max-result-buffer, not -m", "")
 }
 
 func TestConfigDeprecatedMaxRetryAttemptsFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-r", "10"})
-	assert.Equal(t, err.Error(), "[deprecated] use -max-retry-attempts, not -r", "")
-	assert.Equal(t, c.MaxRetryAttempts, 10, "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-r", "10"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.MaxRetryAttempts, 10, "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -max-retry-attempts, not -r", "")
 }
 
 func TestConfigDeprecatedNameFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-n", "test-name"})
-	assert.Equal(t, err.Error(), "[deprecated] use -name, not -n", "")
-	assert.Equal(t, c.Name, "test-name", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-n", "test-name"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Name, "test-name", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -name, not -n", "")
 }
 
 func TestConfigDeprecatedPeerAddrFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-s", "localhost:7002"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peer-addr, not -s", "")
-	assert.Equal(t, c.Peer.Addr, "localhost:7002", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-s", "localhost:7002"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Peer.Addr, "localhost:7002", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peer-addr, not -s", "")
 }
 
 func TestConfigDeprecatedPeerBindAddrFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-sl", "127.0.0.1:4003"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peer-bind-addr, not -sl", "")
-	assert.Equal(t, c.Peer.BindAddr, "127.0.0.1:4003", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-sl", "127.0.0.1:4003"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Peer.BindAddr, "127.0.0.1:4003", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peer-bind-addr, not -sl", "")
 }
 
 func TestConfigDeprecatedPeerCAFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-serverCAFile", "/tmp/peer/file.ca"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peer-ca-file, not -serverCAFile", "")
-	assert.Equal(t, c.Peer.CAFile, "/tmp/peer/file.ca", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-serverCAFile", "/tmp/peer/file.ca"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Peer.CAFile, "/tmp/peer/file.ca", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peer-ca-file, not -serverCAFile", "")
 }
 
 func TestConfigDeprecatedPeerCertFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-serverCert", "/tmp/peer/file.cert"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peer-cert-file, not -serverCert", "")
-	assert.Equal(t, c.Peer.CertFile, "/tmp/peer/file.cert", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-serverCert", "/tmp/peer/file.cert"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Peer.CertFile, "/tmp/peer/file.cert", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peer-cert-file, not -serverCert", "")
 }
 
 func TestConfigDeprecatedPeerKeyFileFlag(t *testing.T) {
-	c := NewConfig()
-	err := c.LoadDeprecatedFlags([]string{"-serverKey", "/tmp/peer/file.key"})
-	assert.Equal(t, err.Error(), "[deprecated] use -peer-key-file, not -serverKey", "")
-	assert.Equal(t, c.Peer.KeyFile, "/tmp/peer/file.key", "")
+	_, stderr := capture(func() {
+		c := NewConfig()
+		err := c.LoadFlags([]string{"-serverKey", "/tmp/peer/file.key"})
+		assert.NoError(t, err)
+		assert.Equal(t, c.Peer.KeyFile, "/tmp/peer/file.key", "")
+	})
+	assert.Equal(t, stderr, "[deprecated] use -peer-key-file, not -serverKey", "")
 }
 
-
 //--------------------------------------
 // Helpers
 //--------------------------------------
@@ -588,3 +664,27 @@ func withTempFile(content string, fn func(string)) {
 	defer os.Remove(f.Name())
 	fn(f.Name())
 }
+
+// Captures STDOUT & STDERR and returns the output as strings.
+func capture(fn func()) (string, string) {
+	// Create temp files.
+	tmpout, _ := ioutil.TempFile("", "")
+	defer os.Remove(tmpout.Name())
+	tmperr, _ := ioutil.TempFile("", "")
+	defer os.Remove(tmperr.Name())
+
+	stdout, stderr := os.Stdout, os.Stderr
+	os.Stdout, os.Stderr = tmpout, tmperr
+
+	// Execute function argument and then reassign stdout/stderr.
+	fn()
+	os.Stdout, os.Stderr = stdout, stderr
+
+	// Close temp files and read them.
+	tmpout.Close()
+	bout, _ := ioutil.ReadFile(tmpout.Name())
+	tmperr.Close()
+	berr, _ := ioutil.ReadFile(tmperr.Name())
+
+	return string(bout), string(berr)
+}

server/usage.go

@@ -0,0 +1,57 @@
+package server
+
+import (
+	"strings"
+)
+
+// usage defines the message shown when a help flag is passed to etcd.
+var usage = `
+etcd
+
+Usage:
+  etcd -name <name>
+  etcd -name <name> [-data-dir=<path>]
+  etcd -h | -help
+  etcd -version
+
+Options:
+  -h -help          Show this screen.
+  --version         Show version.
+  -f -force         Force a new configuration to be used.
+  -config=<path>    Path to configuration file.
+  -name=<name>      Name of this node in the etcd cluster.
+  -data-dir=<path>  Path to the data directory.
+  -cors=<origins>   Comma-separated list of CORS origins.
+  -v                Enabled verbose logging.
+  -vv               Enabled very verbose logging.
+
+Cluster Configuration Options:
+  -peers=<peers>      Comma-separated list of peers (ip + port) in the cluster.
+  -peers-file=<path>  Path to a file containing the peer list.
+
+Client Communication Options:
+  -addr=<host:port>   The public host:port used for client communication.
+  -bind-addr=<host>   The listening hostname used for client communication.
+  -ca-file=<path>     Path to the client CA file.
+  -cert-file=<path>   Path to the client cert file.
+  -key-file=<path>    Path to the client key file.
+
+Peer Communication Options:
+  -peer-addr=<host:port>  The public host:port used for peer communication.
+  -peer-bind-addr=<host>  The listening hostname used for peer communication.
+  -peer-ca-file=<path>    Path to the peer CA file.
+  -peer-cert-file=<path>  Path to the peer cert file.
+  -peer-key-file=<path>   Path to the peer key file.
+
+Other Options:
+  -max-result-buffer   Max size of the result buffer.
+  -max-retry-attempts  Number of times a node will try to join a cluster.
+  -max-cluster-size    Maximum number of nodes in the cluster.
+  -snapshot            Open or close the snapshot.
+  -snapshot-count      Number of transactions before issuing a snapshot.
+`
+
+// Usage returns the usage message for etcd.
+func Usage() string {
+	return strings.TrimSpace(usage)
+}