cmd/utils, node: create account manager in package node

The account manager was previously created by packge cmd/utils as part
of flag processing and then passed down into eth.Ethereum through its
config struct. Since we are starting to create nodes which do not have
eth.Ethereum as a registered service, the code was rearranged to
register the account manager as its own service. Making it a service is
ugly though and it doesn't really fix the root cause: creating nodes
without eth.Ethereum requires duplicating lots of code.

This commit splits utils.MakeSystemNode into three functions, making
creation of other node/service configurations easier. It also moves the
account manager into Node so it can be used by those configurations
without requiring package eth.

3 files changed, 89 insertions, 11 deletions

diff --git a/node/config.go b/node/config.go
index bc9fec618..432da7015 100644
--- a/node/config.go
+++ b/node/config.go
@@ -27,6 +27,7 @@ import (
 	"runtime"
 	"strings"
 
+	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/logger"
@@ -36,10 +37,11 @@ import (
 )
 
 var (
-	datadirPrivateKey   = "nodekey"            // Path within the datadir to the node's private key
-	datadirStaticNodes  = "static-nodes.json"  // Path within the datadir to the static node list
-	datadirTrustedNodes = "trusted-nodes.json" // Path within the datadir to the trusted node list
-	datadirNodeDatabase = "nodes"              // Path within the datadir to store the node infos
+	datadirPrivateKey      = "nodekey"            // Path within the datadir to the node's private key
+	datadirDefaultKeyStore = "keystore"           // Path within the datadir to the keystore
+	datadirStaticNodes     = "static-nodes.json"  // Path within the datadir to the static node list
+	datadirTrustedNodes    = "trusted-nodes.json" // Path within the datadir to the trusted node list
+	datadirNodeDatabase    = "nodes"              // Path within the datadir to store the node infos
 )
 
 // Config represents a small collection of configuration values to fine tune the
@@ -53,6 +55,19 @@ type Config struct {
 	// in memory.
 	DataDir string
 
+	// KeyStoreDir is the file system folder that contains private keys. The directory can
+	// be specified as a relative path, in which case it is resolved relative to the
+	// current directory.
+	//
+	// If KeyStoreDir is empty, the default location is the "keystore" subdirectory of
+	// DataDir. If DataDir is unspecified and KeyStoreDir is empty, an ephemeral directory
+	// is created by New and destroyed when the node is stopped.
+	KeyStoreDir string
+
+	// UseLightweightKDF lowers the memory and CPU requirements of the key store
+	// scrypt KDF at the expense of security.
+	UseLightweightKDF bool
+
 	// IPCPath is the requested location to place the IPC endpoint. If the path is
 	// a simple file name, it is placed inside the data directory (or on the root
 	// pipe path on Windows), whereas if it's a resolvable path name (absolute or
@@ -278,3 +293,38 @@ func (c *Config) parsePersistentNodes(file string) []*discover.Node {
 	}
 	return nodes
 }
+
+func makeAccountManager(conf *Config) (am *accounts.Manager, ephemeralKeystore string, err error) {
+	scryptN := accounts.StandardScryptN
+	scryptP := accounts.StandardScryptP
+	if conf.UseLightweightKDF {
+		scryptN = accounts.LightScryptN
+		scryptP = accounts.LightScryptP
+	}
+
+	var keydir string
+	switch {
+	case filepath.IsAbs(conf.KeyStoreDir):
+		keydir = conf.KeyStoreDir
+	case conf.DataDir != "":
+		if conf.KeyStoreDir == "" {
+			keydir = filepath.Join(conf.DataDir, datadirDefaultKeyStore)
+		} else {
+			keydir, err = filepath.Abs(conf.KeyStoreDir)
+		}
+	case conf.KeyStoreDir != "":
+		keydir, err = filepath.Abs(conf.KeyStoreDir)
+	default:
+		// There is no datadir.
+		keydir, err = ioutil.TempDir("", "go-ethereum-keystore")
+		ephemeralKeystore = keydir
+	}
+	if err != nil {
+		return nil, "", err
+	}
+	if err := os.MkdirAll(keydir, 0700); err != nil {
+		return nil, "", err
+	}
+
+	return accounts.NewManager(keydir, scryptN, scryptP), ephemeralKeystore, nil
+}
diff --git a/node/node.go b/node/node.go
index ac8a7e8f0..f3be2f763 100644
--- a/node/node.go
+++ b/node/node.go
@@ -26,6 +26,7 @@ import (
 	"sync"
 	"syscall"
 
+	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/internal/debug"
 	"github.com/ethereum/go-ethereum/logger"
@@ -49,6 +50,9 @@ type Node struct {
 	datadir  string         // Path to the currently used data directory
 	eventmux *event.TypeMux // Event multiplexer used between the services of a stack
 
+	accman            *accounts.Manager
+	ephemeralKeystore string // if non-empty, the key directory that will be removed by Stop
+
 	serverConfig p2p.Config
 	server       *p2p.Server // Currently running P2P networking layer
 
@@ -90,13 +94,20 @@ func New(conf *Config) (*Node, error) {
 			return nil, err
 		}
 	}
+	am, ephemeralKeystore, err := makeAccountManager(conf)
+	if err != nil {
+		return nil, err
+	}
+
 	// Assemble the networking layer and the node itself
 	nodeDbPath := ""
 	if conf.DataDir != "" {
 		nodeDbPath = filepath.Join(conf.DataDir, datadirNodeDatabase)
 	}
 	return &Node{
-		datadir: conf.DataDir,
+		datadir:           conf.DataDir,
+		accman:            am,
+		ephemeralKeystore: ephemeralKeystore,
 		serverConfig: p2p.Config{
 			PrivateKey:      conf.NodeKey(),
 			Name:            conf.Name,
@@ -156,9 +167,10 @@ func (n *Node) Start() error {
 	for _, constructor := range n.serviceFuncs {
 		// Create a new context for the particular service
 		ctx := &ServiceContext{
-			datadir:  n.datadir,
-			services: make(map[reflect.Type]Service),
-			EventMux: n.eventmux,
+			datadir:        n.datadir,
+			services:       make(map[reflect.Type]Service),
+			EventMux:       n.eventmux,
+			AccountManager: n.accman,
 		}
 		for kind, s := range services { // copy needed for threaded access
 			ctx.services[kind] = s
@@ -473,9 +485,18 @@ func (n *Node) Stop() error {
 	n.server = nil
 	close(n.stop)
 
+	// Remove the keystore if it was created ephemerally.
+	var keystoreErr error
+	if n.ephemeralKeystore != "" {
+		keystoreErr = os.RemoveAll(n.ephemeralKeystore)
+	}
+
 	if len(failure.Services) > 0 {
 		return failure
 	}
+	if keystoreErr != nil {
+		return keystoreErr
+	}
 	return nil
 }
 
@@ -548,6 +569,11 @@ func (n *Node) DataDir() string {
 	return n.datadir
 }
 
+// AccountManager retrieves the account manager used by the protocol stack.
+func (n *Node) AccountManager() *accounts.Manager {
+	return n.accman
+}
+
 // IPCEndpoint retrieves the current IPC endpoint used by the protocol stack.
 func (n *Node) IPCEndpoint() string {
 	return n.ipcEndpoint
diff --git a/node/service.go b/node/service.go
index 4d9a6e42c..51531466b 100644
--- a/node/service.go
+++ b/node/service.go
@@ -20,6 +20,7 @@ import (
 	"path/filepath"
 	"reflect"
 
+	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/p2p"
@@ -30,9 +31,10 @@ import (
 // the protocol stack, that is passed to all constructors to be optionally used;
 // as well as utility methods to operate on the service environment.
 type ServiceContext struct {
-	datadir  string                   // Data directory for protocol persistence
-	services map[reflect.Type]Service // Index of the already constructed services
-	EventMux *event.TypeMux           // Event multiplexer used for decoupled notifications
+	datadir        string                   // Data directory for protocol persistence
+	services       map[reflect.Type]Service // Index of the already constructed services
+	EventMux       *event.TypeMux           // Event multiplexer used for decoupled notifications
+	AccountManager *accounts.Manager        // Account manager created by the node.
 }
 
 // OpenDatabase opens an existing database with the given name (or creates one