path: root/cmd/utils/flags.go

// Copyright 2015 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

// Package utils contains internal helper functions for go-ethereum commands.
package utils

import (
    "crypto/ecdsa"
    "fmt"
    "io/ioutil"
    "math/big"
    "os"
    "path/filepath"
    "runtime"
    "strconv"
    "strings"

    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/accounts/keystore"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/consensus/ethash"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/core/state"
    "github.com/ethereum/go-ethereum/core/vm"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/eth"
    "github.com/ethereum/go-ethereum/eth/downloader"
    "github.com/ethereum/go-ethereum/eth/gasprice"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/ethstats"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/les"
    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/metrics"
    "github.com/ethereum/go-ethereum/node"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/discover"
    "github.com/ethereum/go-ethereum/p2p/discv5"
    "github.com/ethereum/go-ethereum/p2p/nat"
    "github.com/ethereum/go-ethereum/p2p/netutil"
    "github.com/ethereum/go-ethereum/params"
    whisper "github.com/ethereum/go-ethereum/whisper/whisperv5"
    "gopkg.in/urfave/cli.v1"
)

var (
    CommandHelpTemplate = `{{.cmd.Name}}{{if .cmd.Subcommands}} command{{end}}{{if .cmd.Flags}} [command options]{{end}} [arguments...]
{{if .cmd.Description}}{{.cmd.Description}}
{{end}}{{if .cmd.Subcommands}}
SUBCOMMANDS:
    {{range .cmd.Subcommands}}{{.cmd.Name}}{{with .cmd.ShortName}}, {{.cmd}}{{end}}{{ "\t" }}{{.cmd.Usage}}
    {{end}}{{end}}{{if .categorizedFlags}}
{{range $idx, $categorized := .categorizedFlags}}{{$categorized.Name}} OPTIONS:
{{range $categorized.Flags}}{{"\t"}}{{.}}
{{end}}
{{end}}{{end}}`
)

func init() {
    cli.AppHelpTemplate = `{{.Name}} {{if .Flags}}[global options] {{end}}command{{if .Flags}} [command options]{{end}} [arguments...]

VERSION:
   {{.Version}}

COMMANDS:
   {{range .Commands}}{{.Name}}{{with .ShortName}}, {{.}}{{end}}{{ "\t" }}{{.Usage}}
   {{end}}{{if .Flags}}
GLOBAL OPTIONS:
   {{range .Flags}}{{.}}
   {{end}}{{end}}
`

    cli.CommandHelpTemplate = CommandHelpTemplate
}

// NewApp creates an app with sane defaults.
func NewApp(gitCommit, usage string) *cli.App {
    app := cli.NewApp()
    app.Name = filepath.Base(os.Args[0])
    app.Author = ""
    //app.Authors = nil
    app.Email = ""
    app.Version = params.Version
    if gitCommit != "" {
        app.Version += "-" + gitCommit[:8]
    }
    app.Usage = usage
    return app
}

// These are all the command line flags we support.
// If you add to this list, please remember to include the
// flag in the appropriate command definition.
//
// The flags are defined here so their names and help texts
// are the same for all commands.

var (
    // General settings
    DataDirFlag = DirectoryFlag{
        Name:  "datadir",
        Usage: "Data directory for the databases and keystore",
        Value: DirectoryString{node.DefaultDataDir()},
    }
    KeyStoreDirFlag = DirectoryFlag{
        Name:  "keystore",
        Usage: "Directory for the keystore (default = inside the datadir)",
    }
    NoUSBFlag = cli.BoolFlag{
        Name:  "nousb",
        Usage: "Disables monitoring for and managine USB hardware wallets",
    }
    EthashCacheDirFlag = DirectoryFlag{
        Name:  "ethash.cachedir",
        Usage: "Directory to store the ethash verification caches (default = inside the datadir)",
    }
    EthashCachesInMemoryFlag = cli.IntFlag{
        Name:  "ethash.cachesinmem",
        Usage: "Number of recent ethash caches to keep in memory (16MB each)",
        Value: eth.DefaultConfig.EthashCachesInMem,
    }
    EthashCachesOnDiskFlag = cli.IntFlag{
        Name:  "ethash.cachesondisk",
        Usage: "Number of recent ethash caches to keep on disk (16MB each)",
        Value: eth.DefaultConfig.EthashCachesOnDisk,
    }
    EthashDatasetDirFlag = DirectoryFlag{
        Name:  "ethash.dagdir",
        Usage: "Directory to store the ethash mining DAGs (default = inside home folder)",
        Value: DirectoryString{eth.DefaultConfig.EthashDatasetDir},
    }
    EthashDatasetsInMemoryFlag = cli.IntFlag{
        Name:  "ethash.dagsinmem",
        Usage: "Number of recent ethash mining DAGs to keep in memory (1+GB each)",
        Value: eth.DefaultConfig.EthashDatasetsInMem,
    }
    EthashDatasetsOnDiskFlag = cli.IntFlag{
        Name:  "ethash.dagsondisk",
        Usage: "Number of recent ethash mining DAGs to keep on disk (1+GB each)",
        Value: eth.DefaultConfig.EthashDatasetsOnDisk,
    }
    NetworkIdFlag = cli.Uint64Flag{
        Name:  "networkid",
        Usage: "Network identifier (integer, 1=Frontier, 2=Morden (disused), 3=Ropsten, 4=Rinkeby)",
        Value: eth.DefaultConfig.NetworkId,
    }
    TestnetFlag = cli.BoolFlag{
        Name:  "testnet",
        Usage: "Ropsten network: pre-configured proof-of-work test network",
    }
    RinkebyFlag = cli.BoolFlag{
        Name:  "rinkeby",
        Usage: "Rinkeby network: pre-configured proof-of-authority test network",
    }
    DevModeFlag = cli.BoolFlag{
        Name:  "dev",
        Usage: "Developer mode: pre-configured private network with several debugging flags",
    }
    IdentityFlag = cli.StringFlag{
        Name:  "identity",
        Usage: "Custom node name",
    }
    DocRootFlag = DirectoryFlag{
        Name:  "docroot",
        Usage: "Document Root for HTTPClient file scheme",
        Value: DirectoryString{homeDir()},
    }
    FastSyncFlag = cli.BoolFlag{
        Name:  "fast",
        Usage: "Enable fast syncing through state downloads",
    }
    LightModeFlag = cli.BoolFlag{
        Name:  "light",
        Usage: "Enable light client mode",
    }
    defaultSyncMode = eth.DefaultConfig.SyncMode
    SyncModeFlag    = TextMarshalerFlag{
        Name:  "syncmode",
        Usage: `Blockchain sync mode ("fast", "full", or "light")`,
        Value: &defaultSyncMode,
    }

    LightServFlag = cli.IntFlag{
        Name:  "lightserv",
        Usage: "Maximum percentage of time allowed for serving LES requests (0-90)",
        Value: 0,
    }
    LightPeersFlag = cli.IntFlag{
        Name:  "lightpeers",
        Usage: "Maximum number of LES client peers",
        Value: 20,
    }
    LightKDFFlag = cli.BoolFlag{
        Name:  "lightkdf",
        Usage: "Reduce key-derivation RAM & CPU usage at some expense of KDF strength",
    }
    // Performance tuning settings
    CacheFlag = cli.IntFlag{
        Name:  "cache",
        Usage: "Megabytes of memory allocated to internal caching (min 16MB / database forced)",
        Value: 128,
    }
    TrieCacheGenFlag = cli.IntFlag{
        Name:  "trie-cache-gens",
        Usage: "Number of trie node generations to keep in memory",
        Value: int(state.MaxTrieCacheGen),
    }
    // Miner settings
    MiningEnabledFlag = cli.BoolFlag{
        Name:  "mine",
        Usage: "Enable mining",
    }
    MinerThreadsFlag = cli.IntFlag{
        Name:  "minerthreads",
        Usage: "Number of CPU threads to use for mining",
        Value: runtime.NumCPU(),
    }
    TargetGasLimitFlag = cli.Uint64Flag{
        Name:  "targetgaslimit",
        Usage: "Target gas limit sets the artificial target gas floor for the blocks to mine",
        Value: params.GenesisGasLimit.Uint64(),
    }
    EtherbaseFlag = cli.StringFlag{
        Name:  "etherbase",
        Usage: "Public address for block mining rewards (default = first account created)",
        Value: "0",
    }
    GasPriceFlag = BigFlag{
        Name:  "gasprice",
        Usage: "Minimal gas price to accept for mining a transactions",
        Value: eth.DefaultConfig.GasPrice,
    }
    ExtraDataFlag = cli.StringFlag{
        Name:  "extradata",
        Usage: "Block extra data set by the miner (default = client version)",
    }
    // Account settings
    UnlockedAccountFlag = cli.StringFlag{
        Name:  "unlock",
        Usage: "Comma separated list of accounts to unlock",
        Value: "",
    }
    PasswordFileFlag = cli.StringFlag{
        Name:  "password",
        Usage: "Password file to use for non-inteactive password input",
        Value: "",
    }

    VMEnableDebugFlag = cli.BoolFlag{
        Name:  "vmdebug",
        Usage: "Record information useful for VM and contract debugging",
    }
    // Logging and debug settings
    EthStatsURLFlag = cli.StringFlag{
        Name:  "ethstats",
        Usage: "Reporting URL of a ethstats service (nodename:secret@host:port)",
    }
    MetricsEnabledFlag = cli.BoolFlag{
        Name:  metrics.MetricsEnabledFlag,
        Usage: "Enable metrics collection and reporting",
    }
    FakePoWFlag = cli.BoolFlag{
        Name:  "fakepow",
        Usage: "Disables proof-of-work verification",
    }
    NoCompactionFlag = cli.BoolFlag{
        Name:  "nocompaction",
        Usage: "Disables db compaction after import",
    }
    // RPC settings
    RPCEnabledFlag = cli.BoolFlag{
        Name:  "rpc",
        Usage: "Enable the HTTP-RPC server",
    }
    RPCListenAddrFlag = cli.StringFlag{
        Name:  "rpcaddr",
        Usage: "HTTP-RPC server listening interface",
        Value: node.DefaultHTTPHost,
    }
    RPCPortFlag = cli.IntFlag{
        Name:  "rpcport",
        Usage: "HTTP-RPC server listening port",
        Value: node.DefaultHTTPPort,
    }
    RPCCORSDomainFlag = cli.StringFlag{
        Name:  "rpccorsdomain",
        Usage: "Comma separated list of domains from which to accept cross origin requests (browser enforced)",
        Value: "",
    }
    RPCApiFlag = cli.StringFlag{
        Name:  "rpcapi",
        Usage: "API's offered over the HTTP-RPC interface",
        Value: "",
    }
    IPCDisabledFlag = cli.BoolFlag{
        Name:  "ipcdisable",
        Usage: "Disable the IPC-RPC server",
    }
    IPCPathFlag = DirectoryFlag{
        Name:  "ipcpath",
        Usage: "Filename for IPC socket/pipe within the datadir (explicit paths escape it)",
    }
    WSEnabledFlag = cli.BoolFlag{
        Name:  "ws",
        Usage: "Enable the WS-RPC server",
    }
    WSListenAddrFlag = cli.StringFlag{
        Name:  "wsaddr",
        Usage: "WS-RPC server listening interface",
        Value: node.DefaultWSHost,
    }
    WSPortFlag = cli.IntFlag{
        Name:  "wsport",
        Usage: "WS-RPC server listening port",
        Value: node.DefaultWSPort,
    }
    WSApiFlag = cli.StringFlag{
        Name:  "wsapi",
        Usage: "API's offered over the WS-RPC interface",
        Value: "",
    }
    WSAllowedOriginsFlag = cli.StringFlag{
        Name:  "wsorigins",
        Usage: "Origins from which to accept websockets requests",
        Value: "",
    }
    ExecFlag = cli.StringFlag{
        Name:  "exec",
        Usage: "Execute JavaScript statement",
    }
    PreloadJSFlag = cli.StringFlag{
        Name:  "preload",
        Usage: "Comma separated list of JavaScript files to preload into the console",
    }

    // Network Settings
    MaxPeersFlag = cli.IntFlag{
        Name:  "maxpeers",
        Usage: "Maximum number of network peers (network disabled if set to 0)",
        Value: 25,
    }
    MaxPendingPeersFlag = cli.IntFlag{
        Name:  "maxpendpeers",
        Usage: "Maximum number of pending connection attempts (defaults used if set to 0)",
        Value: 0,
    }
    ListenPortFlag = cli.IntFlag{
        Name:  "port",
        Usage: "Network listening port",
        Value: 30303,
    }
    BootnodesFlag = cli.StringFlag{
        Name:  "bootnodes",
        Usage: "Comma separated enode URLs for P2P discovery bootstrap (set v4+v5 instead for light servers)",
        Value: "",
    }
    BootnodesV4Flag = cli.StringFlag{
        Name:  "bootnodesv4",
        Usage: "Comma separated enode URLs for P2P v4 discovery bootstrap (light server, full nodes)",
        Value: "",
    }
    BootnodesV5Flag = cli.StringFlag{
        Name:  "bootnodesv5",
        Usage: "Comma separated enode URLs for P2P v5 discovery bootstrap (light server, light nodes)",
        Value: "",
    }
    NodeKeyFileFlag = cli.StringFlag{
        Name:  "nodekey",
        Usage: "P2P node key file",
    }
    NodeKeyHexFlag = cli.StringFlag{
        Name:  "nodekeyhex",
        Usage: "P2P node key as hex (for testing)",
    }
    NATFlag = cli.StringFlag{
        Name:  "nat",
        Usage: "NAT port mapping mechanism (any|none|upnp|pmp|extip:<IP>)",
        Value: "any",
    }
    NoDiscoverFlag = cli.BoolFlag{
        Name:  "nodiscover",
        Usage: "Disables the peer discovery mechanism (manual peer addition)",
    }
    DiscoveryV5Flag = cli.BoolFlag{
        Name:  "v5disc",
        Usage: "Enables the experimental RLPx V5 (Topic Discovery) mechanism",
    }
    NetrestrictFlag = cli.StringFlag{
        Name:  "netrestrict",
        Usage: "Restricts network communication to the given IP networks (CIDR masks)",
    }

    WhisperEnabledFlag = cli.BoolFlag{
        Name:  "shh",
        Usage: "Enable Whisper",
    }

    // ATM the url is left to the user and deployment to
    JSpathFlag = cli.StringFlag{
        Name:  "jspath",
        Usage: "JavaScript root path for `loadScript`",
        Value: ".",
    }

    // Gas price oracle settings
    GpoBlocksFlag = cli.IntFlag{
        Name:  "gpoblocks",
        Usage: "Number of recent blocks to check for gas prices",
        Value: eth.DefaultConfig.GPO.Blocks,
    }
    GpoPercentileFlag = cli.IntFlag{
        Name:  "gpopercentile",
        Usage: "Suggested gas price is the given percentile of a set of recent transaction gas prices",
        Value: eth.DefaultConfig.GPO.Percentile,
    }
)

// MakeDataDir retrieves the currently requested data directory, terminating
// if none (or the empty string) is specified. If the node is starting a testnet,
// the a subdirectory of the specified datadir will be used.
func MakeDataDir(ctx *cli.Context) string {
    if path := ctx.GlobalString(DataDirFlag.Name); path != "" {
        if ctx.GlobalBool(TestnetFlag.Name) {
            return filepath.Join(path, "testnet")
        }
        if ctx.GlobalBool(RinkebyFlag.Name) {
            return filepath.Join(path, "rinkeby")
        }
        return path
    }
    Fatalf("Cannot determine default data directory, please set manually (--datadir)")
    return ""
}

// setNodeKey creates a node key from set command line flags, either loading it
// from a file or as a specified hex value. If neither flags were provided, this
// method returns nil and an emphemeral key is to be generated.
func setNodeKey(ctx *cli.Context, cfg *p2p.Config) {
    var (
        hex  = ctx.GlobalString(NodeKeyHexFlag.Name)
        file = ctx.GlobalString(NodeKeyFileFlag.Name)
        key  *ecdsa.PrivateKey
        err  error
    )
    switch {
    case file != "" && hex != "":
        Fatalf("Options %q and %q are mutually exclusive", NodeKeyFileFlag.Name, NodeKeyHexFlag.Name)
    case file != "":
        if key, err = crypto.LoadECDSA(file); err != nil {
            Fatalf("Option %q: %v", NodeKeyFileFlag.Name, err)
        }
        cfg.PrivateKey = key
    case hex != "":
        if key, err = crypto.HexToECDSA(hex); err != nil {
            Fatalf("Option %q: %v", NodeKeyHexFlag.Name, err)
        }
        cfg.PrivateKey = key
    }
}

// setNodeUserIdent creates the user identifier from CLI flags.
func setNodeUserIdent(ctx *cli.Context, cfg *node.Config) {
    if identity := ctx.GlobalString(IdentityFlag.Name); len(identity) > 0 {
        cfg.UserIdent = identity
    }
}

// setBootstrapNodes creates a list of bootstrap nodes from the command line
// flags, reverting to pre-configured ones if none have been specified.
func setBootstrapNodes(ctx *cli.Context, cfg *p2p.Config) {
    urls := params.MainnetBootnodes
    switch {
    case ctx.GlobalIsSet(BootnodesFlag.Name) || ctx.GlobalIsSet(BootnodesV4Flag.Name):
        if ctx.GlobalIsSet(BootnodesV4Flag.Name) {
            urls = strings.Split(ctx.GlobalString(BootnodesV4Flag.Name), ",")
        } else {
            urls = strings.Split(ctx.GlobalString(BootnodesFlag.Name), ",")
        }
    case ctx.GlobalBool(TestnetFlag.Name):
        urls = params.TestnetBootnodes
    case ctx.GlobalBool(RinkebyFlag.Name):
        urls = params.RinkebyBootnodes
    }

    cfg.BootstrapNodes = make([]*discover.Node, 0, len(urls))
    for _, url := range urls {
        node, err := discover.ParseNode(url)
        if err != nil {
            log.Error("Bootstrap URL invalid", "enode", url, "err", err)
            continue
        }
        cfg.BootstrapNodes = append(cfg.BootstrapNodes, node)
    }
}

// setBootstrapNodesV5 creates a list of bootstrap nodes from the command line
// flags, reverting to pre-configured ones if none have been specified.
func setBootstrapNodesV5(ctx *cli.Context, cfg *p2p.Config) {
    urls := params.DiscoveryV5Bootnodes
    switch {
    case ctx.GlobalIsSet(BootnodesFlag.Name) || ctx.GlobalIsSet(BootnodesV5Flag.Name):
        if ctx.GlobalIsSet(BootnodesV5Flag.Name) {
            urls = strings.Split(ctx.GlobalString(BootnodesV5Flag.Name), ",")
        } else {
            urls = strings.Split(ctx.GlobalString(BootnodesFlag.Name), ",")
        }
    case ctx.GlobalBool(RinkebyFlag.Name):
        urls = params.RinkebyV5Bootnodes
    case cfg.BootstrapNodesV5 != nil:
        return // already set, don't apply defaults.
    }

    cfg.BootstrapNodesV5 = make([]*discv5.Node, 0, len(urls))
    for _, url := range urls {
        node, err := discv5.ParseNode(url)
        if err != nil {
            log.Error("Bootstrap URL invalid", "enode", url, "err", err)
            continue
        }
        cfg.BootstrapNodesV5 = append(cfg.BootstrapNodesV5, node)
    }
}

// setListenAddress creates a TCP listening address string from set command
// line flags.
func setListenAddress(ctx *cli.Context, cfg *p2p.Config) {
    if ctx.GlobalIsSet(ListenPortFlag.Name) {
        cfg.ListenAddr = fmt.Sprintf(":%d", ctx.GlobalInt(ListenPortFlag.Name))
    }
}

// setDiscoveryV5Address creates a UDP listening address string from set command
// line flags for the V5 discovery protocol.
func setDiscoveryV5Address(ctx *cli.Context, cfg *p2p.Config) {
    if ctx.GlobalIsSet(ListenPortFlag.Name) {
        cfg.DiscoveryV5Addr = fmt.Sprintf(":%d", ctx.GlobalInt(ListenPortFlag.Name)+1)
    }
}

// setNAT creates a port mapper from command line flags.
func setNAT(ctx *cli.Context, cfg *p2p.Config) {
    if ctx.GlobalIsSet(NATFlag.Name) {
        natif, err := nat.Parse(ctx.GlobalString(NATFlag.Name))
        if err != nil {
            Fatalf("Option %s: %v", NATFlag.Name, err)
        }
        cfg.NAT = natif
    }
}

// splitAndTrim splits input separated by a comma
// and trims excessive white space from the substrings.
func splitAndTrim(input string) []string {
    result := strings.Split(input, ",")
    for i, r := range result {
        result[i] = strings.TrimSpace(r)
    }
    return result
}

// setHTTP creates the HTTP RPC listener interface string from the set
// command line flags, returning empty if the HTTP endpoint is disabled.
func setHTTP(ctx *cli.Context, cfg *node.Config) {
    if ctx.GlobalBool(RPCEnabledFlag.Name) && cfg.HTTPHost == "" {
        cfg.HTTPHost = "127.0.0.1"
        if ctx.GlobalIsSet(RPCListenAddrFlag.Name) {
            cfg.HTTPHost = ctx.GlobalString(RPCListenAddrFlag.Name)
        }
    }

    if ctx.GlobalIsSet(RPCPortFlag.Name) {
        cfg.HTTPPort = ctx.GlobalInt(RPCPortFlag.Name)
    }
    if ctx.GlobalIsSet(RPCCORSDomainFlag.Name) {
        cfg.HTTPCors = splitAndTrim(ctx.GlobalString(RPCCORSDomainFlag.Name))
    }
    if ctx.GlobalIsSet(RPCApiFlag.Name) {
        cfg.HTTPModules = splitAndTrim(ctx.GlobalString(RPCApiFlag.Name))
    }
}

// setWS creates the WebSocket RPC listener interface string from the set
// command line flags, returning empty if the HTTP endpoint is disabled.
func setWS(ctx *cli.Context, cfg *node.Config) {
    if ctx.GlobalBool(WSEnabledFlag.Name) && cfg.WSHost == "" {
        cfg.WSHost = "127.0.0.1"
        if ctx.GlobalIsSet(WSListenAddrFlag.Name) {
            cfg.WSHost = ctx.GlobalString(WSListenAddrFlag.Name)
        }
    }

    if ctx.GlobalIsSet(WSPortFlag.Name) {
        cfg.WSPort = ctx.GlobalInt(WSPortFlag.Name)
    }
    if ctx.GlobalIsSet(WSAllowedOriginsFlag.Name) {
        cfg.WSOrigins = splitAndTrim(ctx.GlobalString(WSAllowedOriginsFlag.Name))
    }
    if ctx.GlobalIsSet(WSApiFlag.Name) {
        cfg.WSModules = splitAndTrim(ctx.GlobalString(WSApiFlag.Name))
    }
}

// setIPC creates an IPC path configuration from the set command line flags,
// returning an empty string if IPC was explicitly disabled, or the set path.
func setIPC(ctx *cli.Context, cfg *node.Config) {
    checkExclusive(ctx, IPCDisabledFlag, IPCPathFlag)
    switch {
    case ctx.GlobalBool(IPCDisabledFlag.Name):
        cfg.IPCPath = ""
    case ctx.GlobalIsSet(IPCPathFlag.Name):
        cfg.IPCPath = ctx.GlobalString(IPCPathFlag.Name)
    }
}

// makeDatabaseHandles raises out the number of allowed file handles per process
// for Geth and returns half of the allowance to assign to the database.
func makeDatabaseHandles() int {
    if err := raiseFdLimit(2048); err != nil {
        Fatalf("Failed to raise file descriptor allowance: %v", err)
    }
    limit, err := getFdLimit()
    if err != nil {
        Fatalf("Failed to retrieve file descriptor allowance: %v", err)
    }
    if limit > 2048 { // cap database file descriptors even if more is available
        limit = 2048
    }
    return limit / 2 // Leave half for networking and other stuff
}

// MakeAddress converts an account specified directly as a hex encoded string or
// a key index in the key store to an internal account representation.
func MakeAddress(ks *keystore.KeyStore, account string) (accounts.Account, error) {
    // If the specified account is a valid address, return it
    if common.IsHexAddress(account) {
        return accounts.Account{Address: common.HexToAddress(account)}, nil
    }
    // Otherwise try to interpret the account as a keystore index
    index, err := strconv.Atoi(account)
    if err != nil || index < 0 {
        return accounts.Account{}, fmt.Errorf("invalid account address or index %q", account)
    }
    accs := ks.Accounts()
    if len(accs) <= index {
        return accounts.Account{}, fmt.Errorf("index %d higher than number of accounts %d", index, len(accs))
    }
    return accs[index], nil
}

// setEtherbase retrieves the etherbase either from the directly specified
// command line flags or from the keystore if CLI indexed.
func setEtherbase(ctx *cli.Context, ks *keystore.KeyStore, cfg *eth.Config) {
    if ctx.GlobalIsSet(EtherbaseFlag.Name) {
        account, err := MakeAddress(ks, ctx.GlobalString(EtherbaseFlag.Name))
        if err != nil {
            Fatalf("Option %q: %v", EtherbaseFlag.Name, err)
        }
        cfg.Etherbase = account.Address
        return
    }
    accounts := ks.Accounts()
    if (cfg.Etherbase == common.Address{}) {
        if len(accounts) > 0 {
            cfg.Etherbase = accounts[0].Address
        } else {
            log.Warn("No etherbase set and no accounts found as default")
        }
    }
}

// MakePasswordList reads password lines from the file specified by the global --password flag.
func MakePasswordList(ctx *cli.Context) []string {
    path := ctx.GlobalString(PasswordFileFlag.Name)
    if path == "" {
        return nil
    }
    text, err := ioutil.ReadFile(path)
    if err != nil {
        Fatalf("Failed to read password file: %v", err)
    }
    lines := strings.Split(string(text), "\n")
    // Sanitise DOS line endings.
    for i := range lines {
        lines[i] = strings.TrimRight(lines[i], "\r")
    }
    return lines
}

func SetP2PConfig(ctx *cli.Context, cfg *p2p.Config) {
    setNodeKey(ctx, cfg)
    setNAT(ctx, cfg)
    setListenAddress(ctx, cfg)
    setDiscoveryV5Address(ctx, cfg)
    setBootstrapNodes(ctx, cfg)
    setBootstrapNodesV5(ctx, cfg)

    if ctx.GlobalIsSet(MaxPeersFlag.Name) {
        cfg.MaxPeers = ctx.GlobalInt(MaxPeersFlag.Name)
    }
    if ctx.GlobalIsSet(MaxPendingPeersFlag.Name) {
        cfg.MaxPendingPeers = ctx.GlobalInt(MaxPendingPeersFlag.Name)
    }
    if ctx.GlobalIsSet(NoDiscoverFlag.Name) || ctx.GlobalBool(LightModeFlag.Name) {
        cfg.NoDiscovery = true
    }

    // if we're running a light client or server, force enable the v5 peer discovery
    // unless it is explicitly disabled with --nodiscover note that explicitly specifying
    // --v5disc overrides --nodiscover, in which case the later only disables v4 discovery
    forceV5Discovery := (ctx.GlobalBool(LightModeFlag.Name) || ctx.GlobalInt(LightServFlag.Name) > 0) && !ctx.GlobalBool(NoDiscoverFlag.Name)
    if ctx.GlobalIsSet(DiscoveryV5Flag.Name) {
        cfg.DiscoveryV5 = ctx.GlobalBool(DiscoveryV5Flag.Name)
    } else if forceV5Discovery {
        cfg.DiscoveryV5 = true
    }

    if netrestrict := ctx.GlobalString(NetrestrictFlag.Name); netrestrict != "" {
        list, err := netutil.ParseNetlist(netrestrict)
        if err != nil {
            Fatalf("Option %q: %v", NetrestrictFlag.Name, err)
        }
        cfg.NetRestrict = list
    }

    if ctx.GlobalBool(DevModeFlag.Name) {
        // --dev mode can't use p2p networking.
        cfg.MaxPeers = 0
        cfg.ListenAddr = ":0"
        cfg.DiscoveryV5Addr = ":0"
        cfg.NoDiscovery = true
        cfg.DiscoveryV5 = false
    }
}

// SetNodeConfig applies node-related command line flags to the config.
func SetNodeConfig(ctx *cli.Context, cfg *node.Config) {
    SetP2PConfig(ctx, &cfg.P2P)
    setIPC(ctx, cfg)
    setHTTP(ctx, cfg)
    setWS(ctx, cfg)
    setNodeUserIdent(ctx, cfg)

    switch {
    case ctx.GlobalIsSet(DataDirFlag.Name):
        cfg.DataDir = ctx.GlobalString(DataDirFlag.Name)
    case ctx.GlobalBool(DevModeFlag.Name):
        cfg.DataDir = filepath.Join(os.TempDir(), "ethereum_dev_mode")
    case ctx.GlobalBool(TestnetFlag.Name):
        cfg.DataDir = filepath.Join(node.DefaultDataDir(), "testnet")
    case ctx.GlobalBool(RinkebyFlag.Name):
        cfg.DataDir = filepath.Join(node.DefaultDataDir(), "rinkeby")
    }

    if ctx.GlobalIsSet(KeyStoreDirFlag.Name) {
        cfg.KeyStoreDir = ctx.GlobalString(KeyStoreDirFlag.Name)
    }
    if ctx.GlobalIsSet(LightKDFFlag.Name) {
        cfg.UseLightweightKDF = ctx.GlobalBool(LightKDFFlag.Name)
    }
    if ctx.GlobalIsSet(NoUSBFlag.Name) {
        cfg.NoUSB = ctx.GlobalBool(NoUSBFlag.Name)
    }
}

func setGPO(ctx *cli.Context, cfg *gasprice.Config) {
    if ctx.GlobalIsSet(GpoBlocksFlag.Name) {
        cfg.Blocks = ctx.GlobalInt(GpoBlocksFlag.Name)
    }
    if ctx.GlobalIsSet(GpoPercentileFlag.Name) {
        cfg.Percentile = ctx.GlobalInt(GpoPercentileFlag.Name)
    }
}

func setEthash(ctx *cli.Context, cfg *eth.Config) {
    if ctx.GlobalIsSet(EthashCacheDirFlag.Name) {
        cfg.EthashCacheDir = ctx.GlobalString(EthashCacheDirFlag.Name)
    }
    if ctx.GlobalIsSet(EthashDatasetDirFlag.Name) {
        cfg.EthashDatasetDir = ctx.GlobalString(EthashDatasetDirFlag.Name)
    }
    if ctx.GlobalIsSet(EthashCachesInMemoryFlag.Name) {
        cfg.EthashCachesInMem = ctx.GlobalInt(EthashCachesInMemoryFlag.Name)
    }
    if ctx.GlobalIsSet(EthashCachesOnDiskFlag.Name) {
        cfg.EthashCachesOnDisk = ctx.GlobalInt(EthashCachesOnDiskFlag.Name)
    }
    if ctx.GlobalIsSet(EthashDatasetsInMemoryFlag.Name) {
        cfg.EthashDatasetsInMem = ctx.GlobalInt(EthashDatasetsInMemoryFlag.Name)
    }
    if ctx.GlobalIsSet(EthashDatasetsOnDiskFlag.Name) {
        cfg.EthashDatasetsOnDisk = ctx.GlobalInt(EthashDatasetsOnDiskFlag.Name)
    }
}

func checkExclusive(ctx *cli.Context, flags ...cli.Flag) {
    set := make([]string, 0, 1)
    for _, flag := range flags {
        if ctx.GlobalIsSet(flag.GetName()) {
            set = append(set, "--"+flag.GetName())
        }
    }
    if len(set) > 1 {
        Fatalf("flags %v can't be used at the same time", strings.Join(set, ", "))
    }
}

// SetEthConfig applies eth-related command line flags to the config.
func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
    // Avoid conflicting network flags
    checkExclusive(ctx, DevModeFlag, TestnetFlag, RinkebyFlag)
    checkExclusive(ctx, FastSyncFlag, LightModeFlag, SyncModeFlag)

    ks := stack.AccountManager().Backends(keystore.KeyStoreType)[0].(*keystore.KeyStore)
    setEtherbase(ctx, ks, cfg)
    setGPO(ctx, &cfg.GPO)
    setEthash(ctx, cfg)

    switch {
    case ctx.GlobalIsSet(SyncModeFlag.Name):
        cfg.SyncMode = *GlobalTextMarshaler(ctx, SyncModeFlag.Name).(*downloader.SyncMode)
    case ctx.GlobalBool(FastSyncFlag.Name):
        cfg.SyncMode = downloader.FastSync
    case ctx.GlobalBool(LightModeFlag.Name):
        cfg.SyncMode = downloader.LightSync
    }
    if ctx.GlobalIsSet(LightServFlag.Name) {
        cfg.LightServ = ctx.GlobalInt(LightServFlag.Name)
    }
    if ctx.GlobalIsSet(LightPeersFlag.Name) {
        cfg.LightPeers = ctx.GlobalInt(LightPeersFlag.Name)
    }
    if ctx.GlobalIsSet(NetworkIdFlag.Name) {
        cfg.NetworkId = ctx.GlobalUint64(NetworkIdFlag.Name)
    }

    // Ethereum needs to know maxPeers to calculate the light server peer ratio.
    // TODO(fjl): ensure Ethereum can get MaxPeers from node.
    cfg.MaxPeers = ctx.GlobalInt(MaxPeersFlag.Name)

    if ctx.GlobalIsSet(CacheFlag.Name) {
        cfg.DatabaseCache = ctx.GlobalInt(CacheFlag.Name)
    }
    cfg.DatabaseHandles = makeDatabaseHandles()

    if ctx.GlobalIsSet(MinerThreadsFlag.Name) {
        cfg.MinerThreads = ctx.GlobalInt(MinerThreadsFlag.Name)
    }
    if ctx.GlobalIsSet(DocRootFlag.Name) {
        cfg.DocRoot = ctx.GlobalString(DocRootFlag.Name)
    }
    if ctx.GlobalIsSet(ExtraDataFlag.Name) {
        cfg.ExtraData = []byte(ctx.GlobalString(ExtraDataFlag.Name))
    }
    if ctx.GlobalIsSet(GasPriceFlag.Name) {
        cfg.GasPrice = GlobalBig(ctx, GasPriceFlag.Name)
    }
    if ctx.GlobalIsSet(VMEnableDebugFlag.Name) {
        // TODO(fjl): force-enable this in --dev mode
        cfg.EnablePreimageRecording = ctx.GlobalBool(VMEnableDebugFlag.Name)
    }

    // Override any default configs for hard coded networks.
    switch {
    case ctx.GlobalBool(TestnetFlag.Name):
        if !ctx.GlobalIsSet(NetworkIdFlag.Name) {
            cfg.NetworkId = 3
        }
        cfg.Genesis = core.DefaultTestnetGenesisBlock()
    case ctx.GlobalBool(RinkebyFlag.Name):
        if !ctx.GlobalIsSet(NetworkIdFlag.Name) {
            cfg.NetworkId = 4
        }
        cfg.Genesis = core.DefaultRinkebyGenesisBlock()
    case ctx.GlobalBool(DevModeFlag.Name):
        cfg.Genesis = core.DevGenesisBlock()
        if !ctx.GlobalIsSet(GasPriceFlag.Name) {
            cfg.GasPrice = new(big.Int)
        }
        cfg.PowTest = true
    }

    // TODO(fjl): move trie cache generations into config
    if gen := ctx.GlobalInt(TrieCacheGenFlag.Name); gen > 0 {
        state.MaxTrieCacheGen = uint16(gen)
    }
}

// RegisterEthService adds an Ethereum client to the stack.
func RegisterEthService(stack *node.Node, cfg *eth.Config) {
    var err error
    if cfg.SyncMode == downloader.LightSync {
        err = stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
            return les.New(ctx, cfg)
        })
    } else {
        err = stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
            fullNode, err := eth.New(ctx, cfg)
            if fullNode != nil && cfg.LightServ > 0 {
                ls, _ := les.NewLesServer(fullNode, cfg)
                fullNode.AddLesServer(ls)
            }
            return fullNode, err
        })
    }
    if err != nil {
        Fatalf("Failed to register the Ethereum service: %v", err)
    }
}

// RegisterShhService configures Whisper and adds it to the given node.
func RegisterShhService(stack *node.Node) {
    if err := stack.Register(func(*node.ServiceContext) (node.Service, error) { return whisper.New(), nil }); err != nil {
        Fatalf("Failed to register the Whisper service: %v", err)
    }
}

// RegisterEthStatsService configures the Ethereum Stats daemon and adds it to
// th egiven node.
func RegisterEthStatsService(stack *node.Node, url string) {
    if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
        // Retrieve both eth and les services
        var ethServ *eth.Ethereum
        ctx.Service(&ethServ)

        var lesServ *les.LightEthereum
        ctx.Service(&lesServ)

        return ethstats.New(url, ethServ, lesServ)
    }); err != nil {
        Fatalf("Failed to register the Ethereum Stats service: %v", err)
    }
}

// SetupNetwork configures the system for either the main net or some test network.
func SetupNetwork(ctx *cli.Context) {
    // TODO(fjl): move target gas limit into config
    params.TargetGasLimit = new(big.Int).SetUint64(ctx.GlobalUint64(TargetGasLimitFlag.Name))
}

// MakeChainDatabase open an LevelDB using the flags passed to the client and will hard crash if it fails.
func MakeChainDatabase(ctx *cli.Context, stack *node.Node) ethdb.Database {
    var (
        cache   = ctx.GlobalInt(CacheFlag.Name)
        handles = makeDatabaseHandles()
    )
    name := "chaindata"
    if ctx.GlobalBool(LightModeFlag.Name) {
        name = "lightchaindata"
    }
    chainDb, err := stack.OpenDatabase(name, cache, handles)
    if err != nil {
        Fatalf("Could not open database: %v", err)
    }
    return chainDb
}

func MakeGenesis(ctx *cli.Context) *core.Genesis {
    var genesis *core.Genesis
    switch {
    case ctx.GlobalBool(TestnetFlag.Name):
        genesis = core.DefaultTestnetGenesisBlock()
    case ctx.GlobalBool(RinkebyFlag.Name):
        genesis = core.DefaultRinkebyGenesisBlock()
    case ctx.GlobalBool(DevModeFlag.Name):
        genesis = core.DevGenesisBlock()
    }
    return genesis
}

// MakeChain creates a chain manager from set command line flags.
func MakeChain(ctx *cli.Context, stack *node.Node) (chain *core.BlockChain, chainDb ethdb.Database) {
    var err error
    chainDb = MakeChainDatabase(ctx, stack)

    engine := ethash.NewFaker()
    if !ctx.GlobalBool(FakePoWFlag.Name) {
        engine = ethash.New("", 1, 0, "", 1, 0)
    }
    config, _, err := core.SetupGenesisBlock(chainDb, MakeGenesis(ctx))
    if err != nil {
        Fatalf("%v", err)
    }
    vmcfg := vm.Config{EnablePreimageRecording: ctx.GlobalBool(VMEnableDebugFlag.Name)}
    chain, err = core.NewBlockChain(chainDb, config, engine, new(event.TypeMux), vmcfg)
    if err != nil {
        Fatalf("Can't create BlockChain: %v", err)
    }
    return chain, chainDb
}

// MakeConsolePreloads retrieves the absolute paths for the console JavaScript
// scripts to preload before starting.
func MakeConsolePreloads(ctx *cli.Context) []string {
    // Skip preloading if there's nothing to preload
    if ctx.GlobalString(PreloadJSFlag.Name) == "" {
        return nil
    }
    // Otherwise resolve absolute paths and return them
    preloads := []string{}

    assets := ctx.GlobalString(JSpathFlag.Name)
    for _, file := range strings.Split(ctx.GlobalString(PreloadJSFlag.Name), ",") {
        preloads = append(preloads, common.AbsolutePath(assets, strings.TrimSpace(file)))
    }
    return preloads
}

// MigrateFlags sets the global flag from a local flag when it's set.
// This is a temporary function used for migrating old command/flags to the
// new format.
//
// e.g. geth account new --keystore /tmp/mykeystore --lightkdf
//
// is equivalent after calling this method with:
//
// geth --keystore /tmp/mykeystore --lightkdf account new
//
// This allows the use of the existing configuration functionality.
// When all flags are migrated this function can be removed and the existing
// configuration functionality must be changed that is uses local flags
func MigrateFlags(action func(ctx *cli.Context) error) func(*cli.Context) error {
    return func(ctx *cli.Context) error {
        for _, name := range ctx.FlagNames() {
            if ctx.IsSet(name) {
                ctx.GlobalSet(name, ctx.String(name))
            }
        }
        return action(ctx)
    }
}