github.com/kisexp/xdchain@v0.0.0-20211206025815-490d6b732aa7/node/config.go (about)

     1  // Copyright 2014 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package node
    18  
    19  import (
    20  	"crypto/ecdsa"
    21  	"fmt"
    22  	"io/ioutil"
    23  	"os"
    24  	"path/filepath"
    25  	"runtime"
    26  	"strings"
    27  	"sync"
    28  
    29  	"github.com/kisexp/xdchain/accounts"
    30  	"github.com/kisexp/xdchain/accounts/external"
    31  	"github.com/kisexp/xdchain/accounts/keystore"
    32  	"github.com/kisexp/xdchain/accounts/pluggable"
    33  	"github.com/kisexp/xdchain/accounts/scwallet"
    34  	"github.com/kisexp/xdchain/accounts/usbwallet"
    35  	"github.com/kisexp/xdchain/common"
    36  	"github.com/kisexp/xdchain/crypto"
    37  	"github.com/kisexp/xdchain/log"
    38  	"github.com/kisexp/xdchain/p2p"
    39  	"github.com/kisexp/xdchain/p2p/enode"
    40  	"github.com/kisexp/xdchain/params"
    41  	"github.com/kisexp/xdchain/plugin"
    42  	"github.com/kisexp/xdchain/rpc"
    43  )
    44  
    45  const (
    46  	datadirPrivateKey      = "nodekey"            // Path within the datadir to the node's private key
    47  	datadirDefaultKeyStore = "keystore"           // Path within the datadir to the keystore
    48  	datadirStaticNodes     = "static-nodes.json"  // Path within the datadir to the static node list
    49  	datadirTrustedNodes    = "trusted-nodes.json" // Path within the datadir to the trusted node list
    50  	datadirNodeDatabase    = "nodes"              // Path within the datadir to store the node infos
    51  )
    52  
    53  // Config represents a small collection of configuration values to fine tune the
    54  // P2P network layer of a protocol stack. These values can be further extended by
    55  // all registered services.
    56  type Config struct {
    57  	// Name sets the instance name of the node. It must not contain the / character and is
    58  	// used in the devp2p node identifier. The instance name of geth is "geth". If no
    59  	// value is specified, the basename of the current executable is used.
    60  	Name string `toml:"-"`
    61  
    62  	// UserIdent, if set, is used as an additional component in the devp2p node identifier.
    63  	UserIdent string `toml:",omitempty"`
    64  
    65  	// Version should be set to the version number of the program. It is used
    66  	// in the devp2p node identifier.
    67  	Version string `toml:"-"`
    68  
    69  	// DataDir is the file system folder the node should use for any data storage
    70  	// requirements. The configured data directory will not be directly shared with
    71  	// registered services, instead those can use utility methods to create/access
    72  	// databases or flat files. This enables ephemeral nodes which can fully reside
    73  	// in memory.
    74  	DataDir string
    75  
    76  	// RaftLogDir is the file system folder the node use for raft-state, raft-snap and
    77  	// raft-wal folders.
    78  	RaftLogDir string
    79  
    80  	// Configuration of peer-to-peer networking.
    81  	P2P p2p.Config
    82  
    83  	// KeyStoreDir is the file system folder that contains private keys. The directory can
    84  	// be specified as a relative path, in which case it is resolved relative to the
    85  	// current directory.
    86  	//
    87  	// If KeyStoreDir is empty, the default location is the "keystore" subdirectory of
    88  	// DataDir. If DataDir is unspecified and KeyStoreDir is empty, an ephemeral directory
    89  	// is created by New and destroyed when the node is stopped.
    90  	KeyStoreDir string `toml:",omitempty"`
    91  
    92  	// ExternalSigner specifies an external URI for a clef-type signer
    93  	ExternalSigner string `toml:",omitempty"`
    94  
    95  	// UseLightweightKDF lowers the memory and CPU requirements of the key store
    96  	// scrypt KDF at the expense of security.
    97  	UseLightweightKDF bool `toml:",omitempty"`
    98  
    99  	// InsecureUnlockAllowed allows user to unlock accounts in unsafe http environment.
   100  	InsecureUnlockAllowed bool `toml:",omitempty"`
   101  
   102  	// NoUSB disables hardware wallet monitoring and connectivity.
   103  	NoUSB bool `toml:",omitempty"`
   104  
   105  	// SmartCardDaemonPath is the path to the smartcard daemon's socket
   106  	SmartCardDaemonPath string `toml:",omitempty"`
   107  
   108  	// IPCPath is the requested location to place the IPC endpoint. If the path is
   109  	// a simple file name, it is placed inside the data directory (or on the root
   110  	// pipe path on Windows), whereas if it's a resolvable path name (absolute or
   111  	// relative), then that specific path is enforced. An empty path disables IPC.
   112  	IPCPath string
   113  
   114  	// HTTPHost is the host interface on which to start the HTTP RPC server. If this
   115  	// field is empty, no HTTP API endpoint will be started.
   116  	HTTPHost string
   117  
   118  	// HTTPPort is the TCP port number on which to start the HTTP RPC server. The
   119  	// default zero value is/ valid and will pick a port number randomly (useful
   120  	// for ephemeral nodes).
   121  	HTTPPort int `toml:",omitempty"`
   122  
   123  	// HTTPCors is the Cross-Origin Resource Sharing header to send to requesting
   124  	// clients. Please be aware that CORS is a browser enforced security, it's fully
   125  	// useless for custom HTTP clients.
   126  	HTTPCors []string `toml:",omitempty"`
   127  
   128  	// HTTPVirtualHosts is the list of virtual hostnames which are allowed on incoming requests.
   129  	// This is by default {'localhost'}. Using this prevents attacks like
   130  	// DNS rebinding, which bypasses SOP by simply masquerading as being within the same
   131  	// origin. These attacks do not utilize CORS, since they are not cross-domain.
   132  	// By explicitly checking the Host-header, the server will not allow requests
   133  	// made against the server with a malicious host domain.
   134  	// Requests using ip address directly are not affected
   135  	HTTPVirtualHosts []string `toml:",omitempty"`
   136  
   137  	// HTTPModules is a list of API modules to expose via the HTTP RPC interface.
   138  	// If the module list is empty, all RPC API endpoints designated public will be
   139  	// exposed.
   140  	HTTPModules []string
   141  
   142  	// HTTPTimeouts allows for customization of the timeout values used by the HTTP RPC
   143  	// interface.
   144  	HTTPTimeouts rpc.HTTPTimeouts
   145  
   146  	// WSHost is the host interface on which to start the websocket RPC server. If
   147  	// this field is empty, no websocket API endpoint will be started.
   148  	WSHost string
   149  
   150  	// WSPort is the TCP port number on which to start the websocket RPC server. The
   151  	// default zero value is/ valid and will pick a port number randomly (useful for
   152  	// ephemeral nodes).
   153  	WSPort int `toml:",omitempty"`
   154  
   155  	// WSOrigins is the list of domain to accept websocket requests from. Please be
   156  	// aware that the server can only act upon the HTTP request the client sends and
   157  	// cannot verify the validity of the request header.
   158  	WSOrigins []string `toml:",omitempty"`
   159  
   160  	// WSModules is a list of API modules to expose via the websocket RPC interface.
   161  	// If the module list is empty, all RPC API endpoints designated public will be
   162  	// exposed.
   163  	WSModules []string
   164  
   165  	// WSExposeAll exposes all API modules via the WebSocket RPC interface rather
   166  	// than just the public ones.
   167  	//
   168  	// *WARNING* Only set this if the node is running in a trusted network, exposing
   169  	// private APIs to untrusted users is a major security risk.
   170  	WSExposeAll bool `toml:",omitempty"`
   171  
   172  	// GraphQLCors is the Cross-Origin Resource Sharing header to send to requesting
   173  	// clients. Please be aware that CORS is a browser enforced security, it's fully
   174  	// useless for custom HTTP clients.
   175  	GraphQLCors []string `toml:",omitempty"`
   176  
   177  	// GraphQLVirtualHosts is the list of virtual hostnames which are allowed on incoming requests.
   178  	// This is by default {'localhost'}. Using this prevents attacks like
   179  	// DNS rebinding, which bypasses SOP by simply masquerading as being within the same
   180  	// origin. These attacks do not utilize CORS, since they are not cross-domain.
   181  	// By explicitly checking the Host-header, the server will not allow requests
   182  	// made against the server with a malicious host domain.
   183  	// Requests using ip address directly are not affected
   184  	GraphQLVirtualHosts []string `toml:",omitempty"`
   185  
   186  	// Logger is a custom logger to use with the p2p.Server.
   187  	Logger log.Logger `toml:",omitempty"`
   188  
   189  	staticNodesWarning     bool
   190  	trustedNodesWarning    bool
   191  	oldGethResourceWarning bool
   192  	Plugins                *plugin.Settings `toml:",omitempty"`
   193  	// Quorum: EnableNodePermission comes from EnableNodePermissionFlag --permissioned.
   194  	EnableNodePermission bool `toml:",omitempty"`
   195  	EnableMultitenancy   bool `toml:",omitempty"` // comes from MultitenancyFlag flag
   196  }
   197  
   198  // IPCEndpoint resolves an IPC endpoint based on a configured value, taking into
   199  // account the set data folders as well as the designated platform we're currently
   200  // running on.
   201  func (c *Config) IPCEndpoint() string {
   202  	// Short circuit if IPC has not been enabled
   203  	if c.IPCPath == "" {
   204  		return ""
   205  	}
   206  	// On windows we can only use plain top-level pipes
   207  	if runtime.GOOS == "windows" {
   208  		if strings.HasPrefix(c.IPCPath, `\\.\pipe\`) {
   209  			return c.IPCPath
   210  		}
   211  		return `\\.\pipe\` + c.IPCPath
   212  	}
   213  	// Resolve names into the data directory full paths otherwise
   214  	if filepath.Base(c.IPCPath) == c.IPCPath {
   215  		if c.DataDir == "" {
   216  			return filepath.Join(os.TempDir(), c.IPCPath)
   217  		}
   218  		return filepath.Join(c.DataDir, c.IPCPath)
   219  	}
   220  	return c.IPCPath
   221  }
   222  
   223  // NodeDB returns the path to the discovery node database.
   224  func (c *Config) NodeDB() string {
   225  	if c.DataDir == "" {
   226  		return "" // ephemeral
   227  	}
   228  	return c.ResolvePath(datadirNodeDatabase)
   229  }
   230  
   231  // DefaultIPCEndpoint returns the IPC path used by default.
   232  func DefaultIPCEndpoint(clientIdentifier string) string {
   233  	if clientIdentifier == "" {
   234  		clientIdentifier = strings.TrimSuffix(filepath.Base(os.Args[0]), ".exe")
   235  		if clientIdentifier == "" {
   236  			panic("empty executable name")
   237  		}
   238  	}
   239  	config := &Config{DataDir: DefaultDataDir(), IPCPath: clientIdentifier + ".ipc"}
   240  	return config.IPCEndpoint()
   241  }
   242  
   243  // HTTPEndpoint resolves an HTTP endpoint based on the configured host interface
   244  // and port parameters.
   245  func (c *Config) HTTPEndpoint() string {
   246  	if c.HTTPHost == "" {
   247  		return ""
   248  	}
   249  	return fmt.Sprintf("%s:%d", c.HTTPHost, c.HTTPPort)
   250  }
   251  
   252  // DefaultHTTPEndpoint returns the HTTP endpoint used by default.
   253  func DefaultHTTPEndpoint() string {
   254  	config := &Config{HTTPHost: DefaultHTTPHost, HTTPPort: DefaultHTTPPort}
   255  	return config.HTTPEndpoint()
   256  }
   257  
   258  // WSEndpoint resolves a websocket endpoint based on the configured host interface
   259  // and port parameters.
   260  func (c *Config) WSEndpoint() string {
   261  	if c.WSHost == "" {
   262  		return ""
   263  	}
   264  	return fmt.Sprintf("%s:%d", c.WSHost, c.WSPort)
   265  }
   266  
   267  // DefaultWSEndpoint returns the websocket endpoint used by default.
   268  func DefaultWSEndpoint() string {
   269  	config := &Config{WSHost: DefaultWSHost, WSPort: DefaultWSPort}
   270  	return config.WSEndpoint()
   271  }
   272  
   273  // ExtRPCEnabled returns the indicator whether node enables the external
   274  // RPC(http, ws or graphql).
   275  func (c *Config) ExtRPCEnabled() bool {
   276  	return c.HTTPHost != "" || c.WSHost != ""
   277  }
   278  
   279  // NodeName returns the devp2p node identifier.
   280  func (c *Config) NodeName() string {
   281  	name := c.name()
   282  	// Backwards compatibility: previous versions used title-cased "Geth", keep that.
   283  	if name == "geth" || name == "geth-testnet" {
   284  		name = "Geth"
   285  	}
   286  	if c.UserIdent != "" {
   287  		name += "/" + c.UserIdent
   288  	}
   289  	if c.Version != "" {
   290  		name += "/v" + c.Version
   291  	}
   292  	name += "/" + runtime.GOOS + "-" + runtime.GOARCH
   293  	name += "/" + runtime.Version()
   294  	return name
   295  }
   296  
   297  func (c *Config) name() string {
   298  	if c.Name == "" {
   299  		progname := strings.TrimSuffix(filepath.Base(os.Args[0]), ".exe")
   300  		if progname == "" {
   301  			panic("empty executable name, set Config.Name")
   302  		}
   303  		return progname
   304  	}
   305  	return c.Name
   306  }
   307  
   308  // These resources are resolved differently for "geth" instances.
   309  var isOldGethResource = map[string]bool{
   310  	"chaindata":          true,
   311  	"nodes":              true,
   312  	"nodekey":            true,
   313  	"static-nodes.json":  false, // no warning for these because they have their
   314  	"trusted-nodes.json": false, // own separate warning.
   315  }
   316  
   317  // ResolvePath resolves path in the instance directory.
   318  func (c *Config) ResolvePath(path string) string {
   319  	if filepath.IsAbs(path) {
   320  		return path
   321  	}
   322  	if c.DataDir == "" {
   323  		return ""
   324  	}
   325  	// Backwards-compatibility: ensure that data directory files created
   326  	// by geth 1.4 are used if they exist.
   327  	if warn, isOld := isOldGethResource[path]; isOld {
   328  		oldpath := ""
   329  		if c.name() == "geth" {
   330  			oldpath = filepath.Join(c.DataDir, path)
   331  		}
   332  		if oldpath != "" && common.FileExist(oldpath) {
   333  			if warn {
   334  				c.warnOnce(&c.oldGethResourceWarning, "Using deprecated resource file %s, please move this file to the 'geth' subdirectory of datadir.", oldpath)
   335  			}
   336  			return oldpath
   337  		}
   338  	}
   339  	return filepath.Join(c.instanceDir(), path)
   340  }
   341  
   342  func (c *Config) instanceDir() string {
   343  	if c.DataDir == "" {
   344  		return ""
   345  	}
   346  	return filepath.Join(c.DataDir, c.name())
   347  }
   348  
   349  // NodeKey retrieves the currently configured private key of the node, checking
   350  // first any manually set key, falling back to the one found in the configured
   351  // data folder. If no key can be found, a new one is generated.
   352  func (c *Config) NodeKey() *ecdsa.PrivateKey {
   353  	// Use any specifically configured key.
   354  	if c.P2P.PrivateKey != nil {
   355  		return c.P2P.PrivateKey
   356  	}
   357  	// Generate ephemeral key if no datadir is being used.
   358  	if c.DataDir == "" {
   359  		key, err := crypto.GenerateKey()
   360  		if err != nil {
   361  			log.Crit(fmt.Sprintf("Failed to generate ephemeral node key: %v", err))
   362  		}
   363  		return key
   364  	}
   365  
   366  	keyfile := c.ResolvePath(datadirPrivateKey)
   367  	if key, err := crypto.LoadECDSA(keyfile); err == nil {
   368  		return key
   369  	}
   370  	// No persistent key found, generate and store a new one.
   371  	key, err := crypto.GenerateKey()
   372  	if err != nil {
   373  		log.Crit(fmt.Sprintf("Failed to generate node key: %v", err))
   374  	}
   375  	instanceDir := filepath.Join(c.DataDir, c.name())
   376  	if err := os.MkdirAll(instanceDir, 0700); err != nil {
   377  		log.Error(fmt.Sprintf("Failed to persist node key: %v", err))
   378  		return key
   379  	}
   380  	keyfile = filepath.Join(instanceDir, datadirPrivateKey)
   381  	if err := crypto.SaveECDSA(keyfile, key); err != nil {
   382  		log.Error(fmt.Sprintf("Failed to persist node key: %v", err))
   383  	}
   384  	return key
   385  }
   386  
   387  // StaticNodes returns a list of node enode URLs configured as static nodes.
   388  func (c *Config) StaticNodes() []*enode.Node {
   389  	return c.parsePersistentNodes(&c.staticNodesWarning, c.ResolvePath(datadirStaticNodes))
   390  }
   391  
   392  // TrustedNodes returns a list of node enode URLs configured as trusted nodes.
   393  func (c *Config) TrustedNodes() []*enode.Node {
   394  	return c.parsePersistentNodes(&c.trustedNodesWarning, c.ResolvePath(datadirTrustedNodes))
   395  }
   396  
   397  // parsePersistentNodes parses a list of discovery node URLs loaded from a .json
   398  // file from within the data directory.
   399  func (c *Config) parsePersistentNodes(w *bool, path string) []*enode.Node {
   400  	// Short circuit if no node config is present
   401  	if c.DataDir == "" {
   402  		return nil
   403  	}
   404  	if _, err := os.Stat(path); err != nil {
   405  		return nil
   406  	}
   407  	c.warnOnce(w, "Found deprecated node list file %s, please use the TOML config file instead.", path)
   408  
   409  	// Load the nodes from the config file.
   410  	var nodelist []string
   411  	if err := common.LoadJSON(path, &nodelist); err != nil {
   412  		log.Error(fmt.Sprintf("Can't load node list file: %v", err))
   413  		return nil
   414  	}
   415  	// Interpret the list as a discovery node array
   416  	var nodes []*enode.Node
   417  	for _, url := range nodelist {
   418  		if url == "" {
   419  			continue
   420  		}
   421  		node, err := enode.Parse(enode.ValidSchemes, url)
   422  		if err != nil {
   423  			log.Error(fmt.Sprintf("Node URL %s: %v\n", url, err))
   424  			continue
   425  		}
   426  		nodes = append(nodes, node)
   427  	}
   428  	return nodes
   429  }
   430  
   431  // AccountConfig determines the settings for scrypt and keydirectory
   432  func (c *Config) AccountConfig() (int, int, string, error) {
   433  	scryptN := keystore.StandardScryptN
   434  	scryptP := keystore.StandardScryptP
   435  	if c.UseLightweightKDF {
   436  		scryptN = keystore.LightScryptN
   437  		scryptP = keystore.LightScryptP
   438  	}
   439  
   440  	var (
   441  		keydir string
   442  		err    error
   443  	)
   444  	switch {
   445  	case filepath.IsAbs(c.KeyStoreDir):
   446  		keydir = c.KeyStoreDir
   447  	case c.DataDir != "":
   448  		if c.KeyStoreDir == "" {
   449  			keydir = filepath.Join(c.DataDir, datadirDefaultKeyStore)
   450  		} else {
   451  			keydir, err = filepath.Abs(c.KeyStoreDir)
   452  		}
   453  	case c.KeyStoreDir != "":
   454  		keydir, err = filepath.Abs(c.KeyStoreDir)
   455  	}
   456  	return scryptN, scryptP, keydir, err
   457  }
   458  
   459  // Quorum
   460  //
   461  // Make sure plugin base dir exists
   462  func (c *Config) ResolvePluginBaseDir() error {
   463  	if c.Plugins == nil {
   464  		return nil
   465  	}
   466  	baseDir := c.Plugins.BaseDir.String()
   467  	if baseDir == "" {
   468  		baseDir = filepath.Join(c.DataDir, "plugins")
   469  	}
   470  	if !common.FileExist(baseDir) {
   471  		if err := os.MkdirAll(baseDir, 0755); err != nil {
   472  			return err
   473  		}
   474  	}
   475  	absBaseDir, err := filepath.Abs(baseDir)
   476  	if err != nil {
   477  		return err
   478  	}
   479  	c.Plugins.BaseDir = plugin.EnvironmentAwaredValue(absBaseDir)
   480  	return nil
   481  }
   482  
   483  // check if smart-contract-based permissioning is enabled by reading `--permissioned` flag and checking permission config file
   484  func (c *Config) IsPermissionEnabled() bool {
   485  	fullPath := filepath.Join(c.DataDir, params.PERMISSION_MODEL_CONFIG)
   486  	if _, err := os.Stat(fullPath); err != nil {
   487  		log.Warn(fmt.Sprintf("%s file is missing. Smart-contract-based permission service will be disabled", params.PERMISSION_MODEL_CONFIG), "error", err)
   488  		return false
   489  	}
   490  	return true
   491  }
   492  
   493  func makeAccountManager(conf *Config) (*accounts.Manager, string, error) {
   494  	scryptN, scryptP, keydir, err := conf.AccountConfig()
   495  	var ephemeral string
   496  	if keydir == "" {
   497  		// There is no datadir.
   498  		keydir, err = ioutil.TempDir("", "go-ethereum-keystore")
   499  		ephemeral = keydir
   500  	}
   501  
   502  	if err != nil {
   503  		return nil, "", err
   504  	}
   505  	if err := os.MkdirAll(keydir, 0700); err != nil {
   506  		return nil, "", err
   507  	}
   508  	// Assemble the account manager and supported backends
   509  	var backends []accounts.Backend
   510  	if len(conf.ExternalSigner) > 0 {
   511  		log.Info("Using external signer", "url", conf.ExternalSigner)
   512  		if extapi, err := external.NewExternalBackend(conf.ExternalSigner); err == nil {
   513  			backends = append(backends, extapi)
   514  		} else {
   515  			return nil, "", fmt.Errorf("error connecting to external signer: %v", err)
   516  		}
   517  	}
   518  	if len(backends) == 0 {
   519  		// For now, we're using EITHER external signer OR local signers.
   520  		// If/when we implement some form of lockfile for USB and keystore wallets,
   521  		// we can have both, but it's very confusing for the user to see the same
   522  		// accounts in both externally and locally, plus very racey.
   523  		backends = append(backends, keystore.NewKeyStore(keydir, scryptN, scryptP))
   524  		if !conf.NoUSB {
   525  			// Start a USB hub for Ledger hardware wallets
   526  			if ledgerhub, err := usbwallet.NewLedgerHub(); err != nil {
   527  				log.Warn(fmt.Sprintf("Failed to start Ledger hub, disabling: %v", err))
   528  			} else {
   529  				backends = append(backends, ledgerhub)
   530  			}
   531  			// Start a USB hub for Trezor hardware wallets (HID version)
   532  			if trezorhub, err := usbwallet.NewTrezorHubWithHID(); err != nil {
   533  				log.Warn(fmt.Sprintf("Failed to start HID Trezor hub, disabling: %v", err))
   534  			} else {
   535  				backends = append(backends, trezorhub)
   536  			}
   537  			// Start a USB hub for Trezor hardware wallets (WebUSB version)
   538  			if trezorhub, err := usbwallet.NewTrezorHubWithWebUSB(); err != nil {
   539  				log.Warn(fmt.Sprintf("Failed to start WebUSB Trezor hub, disabling: %v", err))
   540  			} else {
   541  				backends = append(backends, trezorhub)
   542  			}
   543  		}
   544  		if len(conf.SmartCardDaemonPath) > 0 {
   545  			// Start a smart card hub
   546  			if schub, err := scwallet.NewHub(conf.SmartCardDaemonPath, scwallet.Scheme, keydir); err != nil {
   547  				log.Warn(fmt.Sprintf("Failed to start smart card hub, disabling: %v", err))
   548  			} else {
   549  				backends = append(backends, schub)
   550  			}
   551  		}
   552  		if conf.Plugins != nil {
   553  			if _, ok := conf.Plugins.Providers[plugin.AccountPluginInterfaceName]; ok {
   554  				pluginBackend := pluggable.NewBackend()
   555  				backends = append(backends, pluginBackend)
   556  			}
   557  		}
   558  	}
   559  
   560  	return accounts.NewManager(&accounts.Config{InsecureUnlockAllowed: conf.InsecureUnlockAllowed}, backends...), ephemeral, nil
   561  }
   562  
   563  var warnLock sync.Mutex
   564  
   565  func (c *Config) warnOnce(w *bool, format string, args ...interface{}) {
   566  	warnLock.Lock()
   567  	defer warnLock.Unlock()
   568  
   569  	if *w {
   570  		return
   571  	}
   572  	l := c.Logger
   573  	if l == nil {
   574  		l = log.Root()
   575  	}
   576  	l.Warn(fmt.Sprintf(format, args...))
   577  	*w = true
   578  }