config.go

// Copyright (c) 2013-2014 The btcsuite developers
// Copyright (c) 2015-2016 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.

package main

import (
	"fmt"
	"net"
	"os"
	"path/filepath"
	"runtime"
	"sort"
	"strconv"
	"strings"

	flags "github.com/btcsuite/go-flags"
	"github.com/decred/dcrutil"
)

const (
	defaultBaseURL          = "http://127.0.0.1:8000"
	defaultClosePoolMsg     = "The stake pool is temporarily closed to new signups."
	defaultConfigFilename   = "dcrstakepool.conf"
	defaultDataDirname      = "data"
	defaultLogLevel         = "info"
	defaultLogDirname       = "logs"
	defaultLogFilename      = "dcrstakepool.log"
	defaultCookieSecure     = false
	defaultDBHost           = "localhost"
	defaultDBName           = "stakepool"
	defaultDBPort           = "3306"
	defaultDBUser           = "stakepool"
	defaultListen           = ":8000"
	defaultPoolEmail        = "admin@example.com"
	defaultPoolFees         = 7.5
	defaultPoolLink         = "https://forum.decred.org/threads/rfp-6-setup-and-operate-10-stake-pools.1361/"
	defaultPublicPath       = "public"
	defaultTemplatePath     = "views"
	defaultRecaptchaSecret  = "6LeIxAcTAAAAAGG-vFI1TnRWxMZNFuojJ4WifJWe"
	defaultRecaptchaSitekey = "6LeIxAcTAAAAAJcZVRqyHh71UMIEGNQ_MXjiZKhI"
	defaultSMTPHost         = ""
	defaultMinServers       = 2
)

var (
	dcrstakepoolHomeDir = dcrutil.AppDataDir("dcrstakepool", false)
	defaultConfigFile   = filepath.Join(dcrstakepoolHomeDir, defaultConfigFilename)
	defaultDataDir      = filepath.Join(dcrstakepoolHomeDir, defaultDataDirname)
	defaultLogDir       = filepath.Join(dcrstakepoolHomeDir, defaultLogDirname)
)

// runServiceCommand is only set to a real function on Windows.  It is used
// to parse and execute service commands specified via the -s flag.
var runServiceCommand func(string) error

// config defines the configuration options for dcrd.
//
// See loadConfig for details on the configuration load process.
type config struct {
	ShowVersion      bool     `short:"V" long:"version" description:"Display version information and exit"`
	ConfigFile       string   `short:"C" long:"configfile" description:"Path to configuration file"`
	DataDir          string   `short:"b" long:"datadir" description:"Directory to store data"`
	LogDir           string   `long:"logdir" description:"Directory to log output."`
	Listen           string   `long:"listen" description:"Listen for connections on the specified interface/port (default: all interfaces, port 8000)"`
	TestNet          bool     `long:"testnet" description:"Use the test network"`
	SimNet           bool     `long:"simnet" description:"Use the simulation test network"`
	Profile          string   `long:"profile" description:"Enable HTTP profiling on given port -- NOTE port must be between 1024 and 65536"`
	CPUProfile       string   `long:"cpuprofile" description:"Write CPU profile to the specified file"`
	MemProfile       string   `long:"memprofile" description:"Write mem profile to the specified file"`
	DebugLevel       string   `short:"d" long:"debuglevel" description:"Logging level for all subsystems {trace, debug, info, warn, error, critical} -- You may also specify <subsystem>=<level>,<subsystem2>=<level>,... to set the log level for individual subsystems -- Use show to list available subsystems"`
	APISecret        string   `long:"apisecret" description:"Secret string used to encrypt API tokens."`
	BaseURL          string   `long:"baseurl" description:"BaseURL to use when sending links via email"`
	ColdWalletExtPub string   `long:"coldwalletextpub" description:"The extended public key to send user stake pool fees to"`
	ClosePool        bool     `long:"closepool" description:"Disable user registration actions (sign-ups and submitting addresses)"`
	ClosePoolMsg     string   `long:"closepoolmsg" description:"Message to display when closepool is set (default: Stake pool is currently oversubscribed)"`
	CookieSecret     string   `long:"cookiesecret" description:"Secret string used to encrypt session data."`
	CookieSecure     bool     `long:"cookiesecure" description:"Set whether cookies can be sent in clear text or not."`
	DBHost           string   `long:"dbhost" description:"Hostname for database connection"`
	DBUser           string   `long:"dbuser" description:"Username for database connection"`
	DBPassword       string   `long:"dbpassword" description:"Password for database connection"`
	DBPort           string   `long:"dbport" description:"Port for database connection"`
	DBName           string   `long:"dbname" description:"Name of database"`
	PublicPath       string   `long:"publicpath" description:"Path to the public folder which contains css/fonts/images/javascript."`
	TemplatePath     string   `long:"templatepath" description:"Path to the views folder which contains html files."`
	RecaptchaSecret  string   `long:"recaptchasecret" description:"Recaptcha Secret"`
	RecaptchaSitekey string   `long:"recaptchasitekey" description:"Recaptcha Sitekey"`
	PoolEmail        string   `long:"poolemail" description:"Email address to for support inquiries"`
	PoolFees         float64  `long:"poolfees" description:"The per-ticket fees the user must send to the pool with their tickets"`
	PoolLink         string   `long:"poollink" description:"URL for support inquiries such as forum, IRC, etc"`
	SMTPFrom         string   `long:"smtpfrom" description:"From address to use on outbound mail"`
	SMTPHost         string   `long:"smtphost" description:"SMTP hostname/ip and port, e.g. mail.example.com:25"`
	SMTPUsername     string   `long:"smtpusername" description:"SMTP username for authentication if required"`
	SMTPPassword     string   `long:"smtppassword" description:"SMTP password for authentication if required"`
	WalletHosts      []string `long:"wallethosts" description:"Hostname for wallet server"`
	WalletUsers      []string `long:"walletusers" description:"Username for wallet server"`
	WalletPasswords  []string `long:"walletpasswords" description:"Pasword for wallet server"`
	WalletCerts      []string `long:"walletcerts" description:"Certificate path for wallet server"`
	SkipVoteBitsSync bool     `long:"skipvotebitssync" descrition:"Skip full vote bits check and sync on startup"`
	Version          string
	AdminIPs         []string `long:"adminips" description:"Expected admin host"`
	MinServers       int      `long:"minservers" description:"Minimum number of wallets connected needed to avoid errors"`
	RealIPHeader     string   `long:"realipheader" description:"The name of an HTTP request header containing the actual remote client IP address, typically set by a reverse proxy. An empty string (default) indicates to use net/Request.RemodeAddr."`
}

// serviceOptions defines the configuration options for the daemon as a service
// on Windows.
type serviceOptions struct {
	ServiceCommand string `short:"s" long:"service" description:"Service command {install, remove, start, stop}"`
}

// cleanAndExpandPath expands environment variables and leading ~ in the
// passed path, cleans the result, and returns it.
func cleanAndExpandPath(path string) string {
	// Expand initial ~ to OS specific home directory.
	if strings.HasPrefix(path, "~") {
		homeDir := filepath.Dir(dcrstakepoolHomeDir)
		path = strings.Replace(path, "~", homeDir, 1)
	}

	// NOTE: The os.ExpandEnv doesn't work with Windows-style %VARIABLE%,
	// but they variables can still be expanded via POSIX-style $VARIABLE.
	return filepath.Clean(os.ExpandEnv(path))
}

// validLogLevel returns whether or not logLevel is a valid debug log level.
func validLogLevel(logLevel string) bool {
	switch logLevel {
	case "trace":
		fallthrough
	case "debug":
		fallthrough
	case "info":
		fallthrough
	case "warn":
		fallthrough
	case "error":
		fallthrough
	case "critical":
		return true
	}
	return false
}

// supportedSubsystems returns a sorted slice of the supported subsystems for
// logging purposes.
func supportedSubsystems() []string {
	// Convert the subsystemLoggers map keys to a slice.
	subsystems := make([]string, 0, len(subsystemLoggers))
	for subsysID := range subsystemLoggers {
		subsystems = append(subsystems, subsysID)
	}

	// Sort the subsytems for stable display.
	sort.Strings(subsystems)
	return subsystems
}

// parseAndSetDebugLevels attempts to parse the specified debug level and set
// the levels accordingly.  An appropriate error is returned if anything is
// invalid.
func parseAndSetDebugLevels(debugLevel string) error {
	// When the specified string doesn't have any delimters, treat it as
	// the log level for all subsystems.
	if !strings.Contains(debugLevel, ",") && !strings.Contains(debugLevel, "=") {
		// Validate debug log level.
		if !validLogLevel(debugLevel) {
			str := "The specified debug level [%v] is invalid"
			return fmt.Errorf(str, debugLevel)
		}

		// Change the logging level for all subsystems.
		setLogLevels(debugLevel)

		return nil
	}

	// Split the specified string into subsystem/level pairs while detecting
	// issues and update the log levels accordingly.
	for _, logLevelPair := range strings.Split(debugLevel, ",") {
		if !strings.Contains(logLevelPair, "=") {
			str := "The specified debug level contains an invalid " +
				"subsystem/level pair [%v]"
			return fmt.Errorf(str, logLevelPair)
		}

		// Extract the specified subsystem and log level.
		fields := strings.Split(logLevelPair, "=")
		subsysID, logLevel := fields[0], fields[1]

		// Validate subsystem.
		if _, exists := subsystemLoggers[subsysID]; !exists {
			str := "The specified subsystem [%v] is invalid -- " +
				"supported subsytems %v"
			return fmt.Errorf(str, subsysID, supportedSubsystems())
		}

		// Validate log level.
		if !validLogLevel(logLevel) {
			str := "The specified debug level [%v] is invalid"
			return fmt.Errorf(str, logLevel)
		}

		setLogLevel(subsysID, logLevel)
	}

	return nil
}

// removeDuplicateAddresses returns a new slice with all duplicate entries in
// addrs removed.
func removeDuplicateAddresses(addrs []string) []string {
	result := make([]string, 0, len(addrs))
	seen := map[string]struct{}{}
	for _, val := range addrs {
		if _, ok := seen[val]; !ok {
			result = append(result, val)
			seen[val] = struct{}{}
		}
	}
	return result
}

// normalizeAddress returns addr with the passed default port appended if
// there is not already a port specified.
func normalizeAddress(addr, defaultPort string) string {
	_, _, err := net.SplitHostPort(addr)
	if err != nil {
		return net.JoinHostPort(addr, defaultPort)
	}
	return addr
}

// normalizeAddresses returns a new slice with all the passed peer addresses
// normalized with the given default port, and all duplicates removed.
func normalizeAddresses(addrs []string, defaultPort string) []string {
	for i, addr := range addrs {
		addrs[i] = normalizeAddress(addr, defaultPort)
	}

	return removeDuplicateAddresses(addrs)
}

// filesExists reports whether the named file or directory exists.
func fileExists(name string) bool {
	if _, err := os.Stat(name); err != nil {
		if os.IsNotExist(err) {
			return false
		}
	}
	return true
}

// newConfigParser returns a new command line flags parser.
func newConfigParser(cfg *config, so *serviceOptions, options flags.Options) *flags.Parser {
	parser := flags.NewParser(cfg, options)
	if runtime.GOOS == "windows" {
		parser.AddGroup("Service Options", "Service Options", so)
	}
	return parser
}

// loadConfig initializes and parses the config using a config file and command
// line options.
//
// The configuration proceeds as follows:
// 	1) Start with a default config with sane settings
// 	2) Pre-parse the command line to check for an alternative config file
// 	3) Load configuration file overwriting defaults with any specified options
// 	4) Parse CLI options and overwrite/add any specified options
//
// The above results in daemon functioning properly without any config settings
// while still allowing the user to override settings with config files and
// command line options.  Command line options always take precedence.
func loadConfig() (*config, []string, error) {
	// Default config.
	cfg := config{
		BaseURL:          defaultBaseURL,
		ClosePool:        false,
		ClosePoolMsg:     defaultClosePoolMsg,
		ConfigFile:       defaultConfigFile,
		DebugLevel:       defaultLogLevel,
		DataDir:          defaultDataDir,
		LogDir:           defaultLogDir,
		CookieSecure:     defaultCookieSecure,
		DBHost:           defaultDBHost,
		DBName:           defaultDBName,
		DBPort:           defaultDBPort,
		DBUser:           defaultDBUser,
		Listen:           defaultListen,
		PoolEmail:        defaultPoolEmail,
		PoolFees:         defaultPoolFees,
		PoolLink:         defaultPoolLink,
		PublicPath:       defaultPublicPath,
		TemplatePath:     defaultTemplatePath,
		RecaptchaSecret:  defaultRecaptchaSecret,
		RecaptchaSitekey: defaultRecaptchaSitekey,
		SMTPHost:         defaultSMTPHost,
		Version:          version(),
		MinServers:       defaultMinServers,
	}

	// Service options which are only added on Windows.
	serviceOpts := serviceOptions{}

	// Pre-parse the command line options to see if an alternative config
	// file or the version flag was specified.  Any errors aside from the
	// help message error can be ignored here since they will be caught by
	// the final parse below.
	preCfg := cfg
	preParser := newConfigParser(&preCfg, &serviceOpts, flags.HelpFlag)
	_, err := preParser.Parse()
	if err != nil {
		if e, ok := err.(*flags.Error); ok && e.Type == flags.ErrHelp {
			fmt.Fprintln(os.Stderr, err)
			return nil, nil, err
		}
	}

	// Show the version and exit if the version flag was specified.
	appName := filepath.Base(os.Args[0])
	appName = strings.TrimSuffix(appName, filepath.Ext(appName))
	usageMessage := fmt.Sprintf("Use %s -h to show usage", appName)
	if preCfg.ShowVersion {
		fmt.Println(appName, "version", version())
		os.Exit(0)
	}

	// Perform service command and exit if specified.  Invalid service
	// commands show an appropriate error.  Only runs on Windows since
	// the runServiceCommand function will be nil when not on Windows.
	if serviceOpts.ServiceCommand != "" && runServiceCommand != nil {
		err := runServiceCommand(serviceOpts.ServiceCommand)
		if err != nil {
			fmt.Fprintln(os.Stderr, err)
		}
		os.Exit(0)
	}

	// Load additional config from file.
	var configFileError error
	parser := newConfigParser(&cfg, &serviceOpts, flags.Default)
	if !(preCfg.SimNet) || preCfg.ConfigFile !=
		defaultConfigFile {

		err := flags.NewIniParser(parser).ParseFile(preCfg.ConfigFile)
		if err != nil {
			if _, ok := err.(*os.PathError); !ok {
				fmt.Fprintf(os.Stderr, "Error parsing config "+
					"file: %v\n", err)
				fmt.Fprintln(os.Stderr, usageMessage)
				return nil, nil, err
			}
			configFileError = err
		}
	}

	// Parse command line options again to ensure they take precedence.
	remainingArgs, err := parser.Parse()
	if err != nil {
		if e, ok := err.(*flags.Error); !ok || e.Type != flags.ErrHelp {
			fmt.Fprintln(os.Stderr, usageMessage)
		}
		return nil, nil, err
	}

	// Create the home directory if it doesn't already exist.
	funcName := "loadConfig"
	err = os.MkdirAll(dcrstakepoolHomeDir, 0700)
	if err != nil {
		// Show a nicer error message if it's because a symlink is
		// linked to a directory that does not exist (probably because
		// it's not mounted).
		if e, ok := err.(*os.PathError); ok && os.IsExist(err) {
			if link, lerr := os.Readlink(e.Path); lerr == nil {
				str := "is symlink %s -> %s mounted?"
				err = fmt.Errorf(str, e.Path, link)
			}
		}

		str := "%s: Failed to create home directory: %v"
		err := fmt.Errorf(str, funcName, err)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	// Multiple networks can't be selected simultaneously.
	numNets := 0

	// Count number of network flags passed; assign active network params
	// while we're at it
	activeNetParams = &mainNetParams
	if cfg.TestNet {
		numNets++
		activeNetParams = &testNet2Params
	}
	if cfg.SimNet {
		numNets++
		// Also disable dns seeding on the simulation test network.
		activeNetParams = &simNetParams
	}
	if numNets > 1 {
		str := "%s: The testnet and simnet params can't be " +
			"used together -- choose one of the three"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

	// Append the network type to the data directory so it is "namespaced"
	// per network.  In addition to the block database, there are other
	// pieces of data that are saved to disk such as address manager state.
	// All data is specific to a network, so namespacing the data directory
	// means each individual piece of serialized data does not have to
	// worry about changing names per network and such.
	cfg.DataDir = cleanAndExpandPath(cfg.DataDir)
	cfg.DataDir = filepath.Join(cfg.DataDir, netName(activeNetParams))

	// Append the network type to the log directory so it is "namespaced"
	// per network in the same fashion as the data directory.
	cfg.LogDir = cleanAndExpandPath(cfg.LogDir)
	cfg.LogDir = filepath.Join(cfg.LogDir, netName(activeNetParams))

	// Special show command to list supported subsystems and exit.
	if cfg.DebugLevel == "show" {
		fmt.Println("Supported subsystems", supportedSubsystems())
		os.Exit(0)
	}

	// Initialize logging at the default logging level.
	initSeelogLogger(filepath.Join(cfg.LogDir, defaultLogFilename))
	setLogLevels(defaultLogLevel)

	// Parse, validate, and set debug log level(s).
	if err := parseAndSetDebugLevels(cfg.DebugLevel); err != nil {
		err := fmt.Errorf("%s: %v", funcName, err.Error())
		fmt.Fprintln(os.Stderr, err)
		fmt.Fprintln(os.Stderr, usageMessage)
		return nil, nil, err
	}

	// Validate profile port number
	if cfg.Profile != "" {
		profilePort, err := strconv.Atoi(cfg.Profile)
		if err != nil || profilePort < 1024 || profilePort > 65535 {
			str := "%s: The profile port must be between 1024 and 65535"
			err := fmt.Errorf(str, funcName)
			fmt.Fprintln(os.Stderr, err)
			fmt.Fprintln(os.Stderr, usageMessage)
			return nil, nil, err
		}
	}

	if cfg.APISecret == "" {
		str := "%s: APIsecret is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if cfg.CookieSecret == "" {
		str := "%s: cookiesecret is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if cfg.DBPassword == "" {
		str := "%s: dbpassword is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.ColdWalletExtPub) == 0 {
		str := "%s: coldwalletextpub is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.AdminIPs) == 0 {
		str := "%s: adminips is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletHosts) == 0 {
		str := "%s: wallethosts is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletCerts) == 0 {
		str := "%s: walletcerts is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletUsers) == 0 {
		str := "%s: walletusers is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletPasswords) == 0 {
		str := "%s: walletpasswords is not set in config"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	// Convert comma separated list into a slice
	cfg.AdminIPs = strings.Split(cfg.AdminIPs[0], ",")
	cfg.WalletHosts = strings.Split(cfg.WalletHosts[0], ",")
	cfg.WalletUsers = strings.Split(cfg.WalletUsers[0], ",")
	cfg.WalletPasswords = strings.Split(cfg.WalletPasswords[0], ",")
	cfg.WalletCerts = strings.Split(cfg.WalletCerts[0], ",")

	// Add default wallet port for the active network if there's no port specified
	cfg.WalletHosts = normalizeAddresses(cfg.WalletHosts, activeNetParams.WalletRPCServerPort)

	if len(cfg.WalletHosts) < 2 {
		str := "%s: you must specify at least 2 wallethosts"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletHosts) != len(cfg.WalletUsers) {
		str := "%s: wallet configuration mismatch (walletusers and wallethosts counts differ)"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletHosts) != len(cfg.WalletPasswords) {
		str := "%s: wallet configuration mismatch (walletpasswords and wallethosts counts differ)"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	if len(cfg.WalletHosts) != len(cfg.WalletCerts) {
		str := "%s: wallet configuration mismatch (walletcerts and wallethosts counts differ)"
		err := fmt.Errorf(str, funcName)
		fmt.Fprintln(os.Stderr, err)
		return nil, nil, err
	}

	for idx := range cfg.WalletCerts {
		if _, err := os.Stat(cfg.WalletCerts[idx]); os.IsNotExist(err) {
			if _, err := os.Stat(filepath.Join(dcrstakepoolHomeDir, cfg.WalletCerts[idx])); os.IsNotExist(err) {
				str := "%s: walletcert " + cfg.WalletCerts[idx] + " and " +
					filepath.Join(dcrstakepoolHomeDir, cfg.WalletCerts[idx]) + " don't exist"
				err := fmt.Errorf(str, funcName)
				fmt.Fprintln(os.Stderr, err)
				return nil, nil, err
			}

			cfg.WalletCerts[idx] = filepath.Join(dcrstakepoolHomeDir, cfg.WalletCerts[idx])
		}
	}

	// Warn about missing config file only after all other configuration is
	// done.  This prevents the warning on help messages and invalid
	// options.  Note this should go directly before the return.
	if configFileError != nil {
		log.Warnf("%v", configFileError)
	}

	return &cfg, remainingArgs, nil
}