storj/pkg/cfgstruct/bind.go

354 lines
11 KiB
Go

// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.
package cfgstruct
import (
"fmt"
"os"
"path/filepath"
"reflect"
"strconv"
"strings"
"time"
"github.com/spf13/cobra"
"github.com/spf13/pflag"
"go.uber.org/zap"
"storj.io/storj/internal/version"
)
// BindOpt is an option for the Bind method
type BindOpt struct {
isDev *bool
isSetup *bool
varfn func(vars map[string]confVar)
}
// ConfDir sets variables for default options called $CONFDIR and $CONFNAME.
func ConfDir(path string) BindOpt {
val := filepath.Clean(os.ExpandEnv(path))
return BindOpt{varfn: func(vars map[string]confVar) {
vars["CONFDIR"] = confVar{val: val, nested: false}
}}
}
// IdentityDir sets a variable for the default option called $IDENTITYDIR.
func IdentityDir(path string) BindOpt {
val := filepath.Clean(os.ExpandEnv(path))
return BindOpt{varfn: func(vars map[string]confVar) {
vars["IDENTITYDIR"] = confVar{val: val, nested: false}
}}
}
// SetupMode issues the bind in a mode where it does not ignore fields with the
// `setup:"true"` tag.
func SetupMode() BindOpt {
setup := true
return BindOpt{isSetup: &setup}
}
// UseDevDefaults forces the bind call to use development defaults unless
// UseReleaseDefaults is provided as a subsequent option.
// Without either, Bind will default to determining which defaults to use
// based on version.Build.Release
func UseDevDefaults() BindOpt {
dev := true
return BindOpt{isDev: &dev}
}
// UseReleaseDefaults forces the bind call to use release defaults unless
// UseDevDefaults is provided as a subsequent option.
// Without either, Bind will default to determining which defaults to use
// based on version.Build.Release
func UseReleaseDefaults() BindOpt {
dev := false
return BindOpt{isDev: &dev}
}
type confVar struct {
val string
nested bool
}
// Bind sets flags on a FlagSet that match the configuration struct
// 'config'. This works by traversing the config struct using the 'reflect'
// package.
func Bind(flags FlagSet, config interface{}, opts ...BindOpt) {
bind(flags, config, opts...)
}
func bind(flags FlagSet, config interface{}, opts ...BindOpt) {
ptrtype := reflect.TypeOf(config)
if ptrtype.Kind() != reflect.Ptr {
panic(fmt.Sprintf("invalid config type: %#v. Expecting pointer to struct.", config))
}
isDev := !version.Build.Release
setupCommand := false
vars := map[string]confVar{}
for _, opt := range opts {
if opt.varfn != nil {
opt.varfn(vars)
}
if opt.isDev != nil {
isDev = *opt.isDev
}
if opt.isSetup != nil {
setupCommand = *opt.isSetup
}
}
bindConfig(flags, "", reflect.ValueOf(config).Elem(), vars, setupCommand, false, isDev)
}
func bindConfig(flags FlagSet, prefix string, val reflect.Value, vars map[string]confVar, setupCommand, setupStruct bool, isDev bool) {
if val.Kind() != reflect.Struct {
panic(fmt.Sprintf("invalid config type: %#v. Expecting struct.", val.Interface()))
}
typ := val.Type()
resolvedVars := make(map[string]string, len(vars))
{
structpath := strings.Replace(prefix, ".", string(filepath.Separator), -1)
for k, v := range vars {
if !v.nested {
resolvedVars[k] = v.val
continue
}
resolvedVars[k] = filepath.Join(v.val, structpath)
}
}
for i := 0; i < typ.NumField(); i++ {
field := typ.Field(i)
fieldval := val.Field(i)
flagname := hyphenate(snakeCase(field.Name))
if field.Tag.Get("noprefix") != "true" {
flagname = prefix + flagname
}
if field.Tag.Get("internal") == "true" {
continue
}
onlyForSetup := (field.Tag.Get("setup") == "true") || setupStruct
// ignore setup params for non setup commands
if !setupCommand && onlyForSetup {
continue
}
fieldaddr := fieldval.Addr().Interface()
if fieldvalue, ok := fieldaddr.(pflag.Value); ok {
help := field.Tag.Get("help")
var def string
if isDev {
def = getDefault(field.Tag, "devDefault", "releaseDefault", "default", flagname)
} else {
def = getDefault(field.Tag, "releaseDefault", "devDefault", "default", flagname)
}
err := fieldvalue.Set(def)
if err != nil {
panic(fmt.Sprintf("invalid default value for %s: %#v, %v", flagname, def, err))
}
flags.Var(fieldvalue, flagname, help)
if onlyForSetup {
setBoolAnnotation(flags, flagname, "setup")
}
if field.Tag.Get("user") == "true" {
setBoolAnnotation(flags, flagname, "user")
}
if field.Tag.Get("hidden") == "true" {
err := flags.MarkHidden(flagname)
if err != nil {
panic(fmt.Sprintf("mark hidden failed %s: %v", flagname, err))
}
}
continue
}
switch field.Type.Kind() {
case reflect.Struct:
if field.Anonymous {
bindConfig(flags, prefix, fieldval, vars, setupCommand, onlyForSetup, isDev)
} else {
bindConfig(flags, flagname+".", fieldval, vars, setupCommand, onlyForSetup, isDev)
}
case reflect.Array:
digits := len(fmt.Sprint(fieldval.Len()))
for j := 0; j < fieldval.Len(); j++ {
padding := strings.Repeat("0", digits-len(fmt.Sprint(j)))
bindConfig(flags, fmt.Sprintf("%s.%s%d.", flagname, padding, j), fieldval.Index(j), vars, setupCommand, onlyForSetup, isDev)
}
default:
help := field.Tag.Get("help")
var def string
if isDev {
def = getDefault(field.Tag, "devDefault", "releaseDefault", "default", flagname)
} else {
def = getDefault(field.Tag, "releaseDefault", "devDefault", "default", flagname)
}
fieldaddr := fieldval.Addr().Interface()
check := func(err error) {
if err != nil {
panic(fmt.Sprintf("invalid default value for %s: %#v", flagname, def))
}
}
switch field.Type {
case reflect.TypeOf(int(0)):
val, err := strconv.ParseInt(def, 0, strconv.IntSize)
check(err)
flags.IntVar(fieldaddr.(*int), flagname, int(val), help)
case reflect.TypeOf(int64(0)):
val, err := strconv.ParseInt(def, 0, 64)
check(err)
flags.Int64Var(fieldaddr.(*int64), flagname, val, help)
case reflect.TypeOf(uint(0)):
val, err := strconv.ParseUint(def, 0, strconv.IntSize)
check(err)
flags.UintVar(fieldaddr.(*uint), flagname, uint(val), help)
case reflect.TypeOf(uint64(0)):
val, err := strconv.ParseUint(def, 0, 64)
check(err)
flags.Uint64Var(fieldaddr.(*uint64), flagname, val, help)
case reflect.TypeOf(time.Duration(0)):
val, err := time.ParseDuration(def)
check(err)
flags.DurationVar(fieldaddr.(*time.Duration), flagname, val, help)
case reflect.TypeOf(float64(0)):
val, err := strconv.ParseFloat(def, 64)
check(err)
flags.Float64Var(fieldaddr.(*float64), flagname, val, help)
case reflect.TypeOf(string("")):
flags.StringVar(
fieldaddr.(*string), flagname, expand(resolvedVars, def), help)
case reflect.TypeOf(bool(false)):
val, err := strconv.ParseBool(def)
check(err)
flags.BoolVar(fieldaddr.(*bool), flagname, val, help)
case reflect.TypeOf([]string(nil)):
flags.StringArrayVar(fieldaddr.(*[]string), flagname, nil, help)
default:
panic(fmt.Sprintf("invalid field type: %s", field.Type.String()))
}
if onlyForSetup {
setBoolAnnotation(flags, flagname, "setup")
}
if field.Tag.Get("user") == "true" {
setBoolAnnotation(flags, flagname, "user")
}
if field.Tag.Get("hidden") == "true" {
err := flags.MarkHidden(flagname)
check(err)
}
}
}
}
func getDefault(tag reflect.StructTag, preferred, opposite, fallback, flagname string) string {
if val, ok := tag.Lookup(preferred); ok {
if _, oppositeExists := tag.Lookup(opposite); !oppositeExists {
panic(fmt.Sprintf("%q defined but %q missing for %v", preferred, opposite, flagname))
}
if _, fallbackExists := tag.Lookup(fallback); fallbackExists {
panic(fmt.Sprintf("%q defined along with %q fallback for %v", preferred, fallback, flagname))
}
return val
}
if _, oppositeExists := tag.Lookup(opposite); oppositeExists {
panic(fmt.Sprintf("%q missing but %q defined for %v", preferred, opposite, flagname))
}
return tag.Get(fallback)
}
func setBoolAnnotation(flagset interface{}, name, key string) {
flags, ok := flagset.(*pflag.FlagSet)
if !ok {
return
}
err := flags.SetAnnotation(name, key, []string{"true"})
if err != nil {
panic(fmt.Sprintf("unable to set %s annotation for %s: %v", key, name, err))
}
}
func expand(vars map[string]string, val string) string {
return os.Expand(val, func(key string) string { return vars[key] })
}
// FindConfigDirParam returns '--config-dir' param from os.Args (if exists)
func FindConfigDirParam() string {
return FindFlagEarly("config-dir")
}
// FindIdentityDirParam returns '--identity-dir' param from os.Args (if exists)
func FindIdentityDirParam() string {
return FindFlagEarly("identity-dir")
}
// FindDefaultsParam returns '--defaults' param from os.Args (if it exists)
func FindDefaultsParam() string {
return FindFlagEarly("defaults")
}
// FindFlagEarly retrieves the value of a flag before `flag.Parse` has been called
func FindFlagEarly(flagName string) string {
// workaround to have early access to 'dir' param
for i, arg := range os.Args {
if strings.HasPrefix(arg, fmt.Sprintf("--%s=", flagName)) {
return strings.TrimPrefix(arg, fmt.Sprintf("--%s=", flagName))
} else if arg == fmt.Sprintf("--%s", flagName) && i < len(os.Args)-1 {
return os.Args[i+1]
}
}
return ""
}
// SetupFlag sets up flags that are needed before `flag.Parse` has been called
func SetupFlag(log *zap.Logger, cmd *cobra.Command, dest *string, name, value, usage string) {
if foundValue := FindFlagEarly(name); foundValue != "" {
value = foundValue
}
cmd.PersistentFlags().StringVar(dest, name, value, usage)
if cmd.PersistentFlags().SetAnnotation(name, "setup", []string{"true"}) != nil {
log.Sugar().Errorf("Failed to set 'setup' annotation for '%s'", name)
}
}
// DefaultsType returns the type of defaults (release/dev) this binary should use
func DefaultsType() string {
// define a flag so that the flag parsing system will be happy.
defaults := strings.ToLower(FindDefaultsParam())
if defaults != "" {
return defaults
}
if version.Build.Release {
return "release"
}
return "dev"
}
// DefaultsFlag sets up the defaults=dev/release flag options, which is needed
// before `flag.Parse` has been called
func DefaultsFlag(cmd *cobra.Command) BindOpt {
// define a flag so that the flag parsing system will be happy.
defaults := DefaultsType()
// we're actually going to ignore this flag entirely and parse the commandline
// arguments early instead
_ = cmd.PersistentFlags().String("defaults", defaults,
"determines which set of configuration defaults to use. can either be 'dev' or 'release'")
switch defaults {
case "dev":
return UseDevDefaults()
case "release":
return UseReleaseDefaults()
default:
panic(fmt.Sprintf("unsupported defaults value %q", FindDefaultsParam()))
}
}