cmd/geth: add --config file flag (#13875)

* p2p/discover, p2p/discv5: add marshaling methods to Node

* p2p/netutil: make Netlist decodable from TOML

* common/math: encode nil HexOrDecimal256 as 0x0

* cmd/geth: add --config file flag

* cmd/geth: add missing license header

* eth: prettify Config again, fix tests

* eth: use gasprice.Config instead of duplicating its fields

* eth/gasprice: hide nil default from dumpconfig output

* cmd/geth: hide genesis block in dumpconfig output

* node: make tests compile

* console: fix tests

* cmd/geth: make TOML keys look exactly like Go struct fields

* p2p: use discovery by default

This makes the zero Config slightly more useful. It also fixes package
node tests because Node detects reuse of the datadir through the
NodeDatabase.

* cmd/geth: make ethstats URL settable through config file

* cmd/faucet: fix configuration

* cmd/geth: dedup attach tests

* eth: add comment for DefaultConfig

* eth: pass downloader.SyncMode in Config

This removes the FastSync, LightSync flags in favour of a more
general SyncMode flag.

* cmd/utils: remove jitvm flags

* cmd/utils: make mutually exclusive flag error prettier

It now reads:

   Fatal: flags --dev, --testnet can't be used at the same time

* p2p: fix typo

* node: add DefaultConfig, use it for geth

* mobile: add missing NoDiscovery option

* cmd/utils: drop MakeNode

This exposed a couple of places that needed to be updated to use
node.DefaultConfig.

* node: fix typo

* eth: make fast sync the default mode

* cmd/utils: remove IPCApiFlag (unused)

* node: remove default IPC path

Set it in the frontends instead.

* cmd/geth: add --syncmode

* cmd/utils: make --ipcdisable and --ipcpath mutually exclusive

* cmd/utils: don't enable WS, HTTP when setting addr

* cmd/utils: fix --identity

1 files changed, 186 insertions, 0 deletions

diff --git a/cmd/geth/config.go b/cmd/geth/config.go
new file mode 100644
index 000000000..86dd4bfdf
--- /dev/null
+++ b/cmd/geth/config.go
@@ -0,0 +1,186 @@
+// 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 main
+
+import (
+	"bufio"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"reflect"
+	"unicode"
+
+	cli "gopkg.in/urfave/cli.v1"
+
+	"github.com/ethereum/go-ethereum/cmd/utils"
+	"github.com/ethereum/go-ethereum/contracts/release"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/params"
+	"github.com/naoina/toml"
+)
+
+var (
+	dumpConfigCommand = cli.Command{
+		Action:      dumpConfig,
+		Name:        "dumpconfig",
+		Usage:       "Show configuration values",
+		ArgsUsage:   "",
+		Category:    "MISCELLANEOUS COMMANDS",
+		Description: `The dumpconfig command shows configuration values.`,
+	}
+
+	configFileFlag = cli.StringFlag{
+		Name:  "config",
+		Usage: "TOML configuration file",
+	}
+)
+
+// These settings ensure that TOML keys use the same names as Go struct fields.
+var tomlSettings = toml.Config{
+	NormFieldName: func(rt reflect.Type, key string) string {
+		return key
+	},
+	FieldToKey: func(rt reflect.Type, field string) string {
+		return field
+	},
+	MissingField: func(rt reflect.Type, field string) error {
+		link := ""
+		if unicode.IsUpper(rune(rt.Name()[0])) && rt.PkgPath() != "main" {
+			link = fmt.Sprintf(", see https://godoc.org/%s#%s for available fields", rt.PkgPath(), rt.Name())
+		}
+		return fmt.Errorf("field '%s' is not defined in %s%s", field, rt.String(), link)
+	},
+}
+
+type ethstatsConfig struct {
+	URL string `toml:",omitempty"`
+}
+
+type gethConfig struct {
+	Eth      eth.Config
+	Node     node.Config
+	Ethstats ethstatsConfig
+}
+
+func loadConfig(file string, cfg *gethConfig) error {
+	f, err := os.Open(file)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	err = tomlSettings.NewDecoder(bufio.NewReader(f)).Decode(cfg)
+	// Add file name to errors that have a line number.
+	if _, ok := err.(*toml.LineError); ok {
+		err = errors.New(file + ", " + err.Error())
+	}
+	return err
+}
+
+func defaultNodeConfig() node.Config {
+	cfg := node.DefaultConfig
+	cfg.Name = clientIdentifier
+	cfg.Version = params.VersionWithCommit(gitCommit)
+	cfg.HTTPModules = append(cfg.HTTPModules, "eth")
+	cfg.WSModules = append(cfg.WSModules, "eth")
+	cfg.IPCPath = "geth.ipc"
+	return cfg
+}
+
+func makeConfigNode(ctx *cli.Context) (*node.Node, gethConfig) {
+	// Load defaults.
+	cfg := gethConfig{
+		Eth:  eth.DefaultConfig,
+		Node: defaultNodeConfig(),
+	}
+
+	// Load config file.
+	if file := ctx.GlobalString(configFileFlag.Name); file != "" {
+		if err := loadConfig(file, &cfg); err != nil {
+			utils.Fatalf("%v", err)
+		}
+	}
+
+	// Apply flags.
+	utils.SetNodeConfig(ctx, &cfg.Node)
+	stack, err := node.New(&cfg.Node)
+	if err != nil {
+		utils.Fatalf("Failed to create the protocol stack: %v", err)
+	}
+	utils.SetEthConfig(ctx, stack, &cfg.Eth)
+	if ctx.GlobalIsSet(utils.EthStatsURLFlag.Name) {
+		cfg.Ethstats.URL = ctx.GlobalString(utils.EthStatsURLFlag.Name)
+	}
+
+	return stack, cfg
+}
+
+func makeFullNode(ctx *cli.Context) *node.Node {
+	stack, cfg := makeConfigNode(ctx)
+
+	utils.RegisterEthService(stack, &cfg.Eth)
+
+	// Whisper must be explicitly enabled, but is auto-enabled in --dev mode.
+	shhEnabled := ctx.GlobalBool(utils.WhisperEnabledFlag.Name)
+	shhAutoEnabled := !ctx.GlobalIsSet(utils.WhisperEnabledFlag.Name) && ctx.GlobalIsSet(utils.DevModeFlag.Name)
+	if shhEnabled || shhAutoEnabled {
+		utils.RegisterShhService(stack)
+	}
+
+	// Add the Ethereum Stats daemon if requested.
+	if cfg.Ethstats.URL != "" {
+		utils.RegisterEthStatsService(stack, cfg.Ethstats.URL)
+	}
+
+	// Add the release oracle service so it boots along with node.
+	if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
+		config := release.Config{
+			Oracle: relOracle,
+			Major:  uint32(params.VersionMajor),
+			Minor:  uint32(params.VersionMinor),
+			Patch:  uint32(params.VersionPatch),
+		}
+		commit, _ := hex.DecodeString(gitCommit)
+		copy(config.Commit[:], commit)
+		return release.NewReleaseService(ctx, config)
+	}); err != nil {
+		utils.Fatalf("Failed to register the Geth release oracle service: %v", err)
+	}
+	return stack
+}
+
+// dumpConfig is the dumpconfig command.
+func dumpConfig(ctx *cli.Context) error {
+	_, cfg := makeConfigNode(ctx)
+	comment := ""
+
+	if cfg.Eth.Genesis != nil {
+		cfg.Eth.Genesis = nil
+		comment += "# Note: this config doesn't contain the genesis block.\n\n"
+	}
+
+	out, err := tomlSettings.Marshal(&cfg)
+	if err != nil {
+		return err
+	}
+	io.WriteString(os.Stdout, comment)
+	os.Stdout.Write(out)
+	return nil
+}