fix(etcd): fixup the name and data dir guessing

- Only generate the name from a hostname if the data dir is not
  specified and the name is not specified

- Only guess the data dir from Name if the data dir wasn't already
  specified

server/config.go

@@ -13,6 +13,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/coreos/etcd/log"
 	"github.com/BurntSushi/toml"
 )
 
@@ -300,6 +301,25 @@ func (c *Config) LoadPeersFile() error {
 	return nil
 }
 
+// DataDirFromName sets the data dir from a machine name and issue a warning
+// that etcd is guessing.
+func (c *Config) DataDirFromName() {
+	c.DataDir = c.Name + ".etcd"
+	log.Warnf("Using the directory %s as the etcd curation directory because a directory was not specified. ", c.DataDir)
+
+	return
+}
+
+// NameFromHostname sets the machine name from the hostname. This is to help
+// people get started without thinking up a name.
+func (c *Config) NameFromHostname() {
+	host, err := os.Hostname()
+	if err != nil && host == "" {
+		log.Fatal("Node name required and hostname not set. e.g. '-name=name'")
+	}
+	c.Name = host
+}
+
 // Reset removes all server configuration files.
 func (c *Config) Reset() error {
 	if err := os.RemoveAll(filepath.Join(c.DataDir, "info")); err != nil {