cmd/stdiscosrv: New discovery server (fixes #4618)

This is a new revision of the discovery server. Relevant changes and
non-changes:

- Protocol towards clients is unchanged.

- Recommended large scale design is still to be deployed nehind nginx (I
  tested, and it's still a lot faster at terminating TLS).

- Database backend is leveldb again, only. It scales enough, is easy to
  setup, and we don't need any backend to take care of.

- Server supports replication. This is a simple TCP channel - protect it
  with a firewall when deploying over the internet. (We deploy this within
  the same datacenter, and with firewall.) Any incoming client announces
  are sent over the replication channel(s) to other peer discosrvs.
  Incoming replication changes are applied to the database as if they came
  from clients, but without the TLS/certificate overhead.

- Metrics are exposed using the prometheus library, when enabled.

- The database values and replication protocol is protobuf, because JSON
  was quite CPU intensive when I tried that and benchmarked it.

- The "Retry-After" value for failed lookups gets slowly increased from
  a default of 120 seconds, by 5 seconds for each failed lookup,
  independently by each discosrv. This lowers the query load over time for
  clients that are never seen. The Retry-After maxes out at 3600 after a
  couple of weeks of this increase. The number of failed lookups is
  stored in the database, now and then (avoiding making each lookup a
  database put).

All in all this means clients can be pointed towards a cluster using
just multiple A / AAAA records to gain both load sharing and redundancy
(if one is down, clients will talk to the remaining ones).

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4648

vendor/github.com/minio/cli/altsrc/altsrc.go

@@ -0,0 +1,3 @@
+package altsrc
+
+//go:generate python ../generate-flag-types altsrc -i ../flag-types.json -o flag_generated.go

vendor/github.com/minio/cli/altsrc/flag.go

@@ -0,0 +1,261 @@
+package altsrc
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"syscall"
+
+	"gopkg.in/urfave/cli.v1"
+)
+
+// FlagInputSourceExtension is an extension interface of cli.Flag that
+// allows a value to be set on the existing parsed flags.
+type FlagInputSourceExtension interface {
+	cli.Flag
+	ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error
+}
+
+// ApplyInputSourceValues iterates over all provided flags and
+// executes ApplyInputSourceValue on flags implementing the
+// FlagInputSourceExtension interface to initialize these flags
+// to an alternate input source.
+func ApplyInputSourceValues(context *cli.Context, inputSourceContext InputSourceContext, flags []cli.Flag) error {
+	for _, f := range flags {
+		inputSourceExtendedFlag, isType := f.(FlagInputSourceExtension)
+		if isType {
+			err := inputSourceExtendedFlag.ApplyInputSourceValue(context, inputSourceContext)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+// InitInputSource is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new
+// input source based on the func provided. If there is no error it will then apply the new input source to any flags
+// that are supported by the input source
+func InitInputSource(flags []cli.Flag, createInputSource func() (InputSourceContext, error)) cli.BeforeFunc {
+	return func(context *cli.Context) error {
+		inputSource, err := createInputSource()
+		if err != nil {
+			return fmt.Errorf("Unable to create input source: inner error: \n'%v'", err.Error())
+		}
+
+		return ApplyInputSourceValues(context, inputSource, flags)
+	}
+}
+
+// InitInputSourceWithContext is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new
+// input source based on the func provided with potentially using existing cli.Context values to initialize itself. If there is
+// no error it will then apply the new input source to any flags that are supported by the input source
+func InitInputSourceWithContext(flags []cli.Flag, createInputSource func(context *cli.Context) (InputSourceContext, error)) cli.BeforeFunc {
+	return func(context *cli.Context) error {
+		inputSource, err := createInputSource(context)
+		if err != nil {
+			return fmt.Errorf("Unable to create input source with context: inner error: \n'%v'", err.Error())
+		}
+
+		return ApplyInputSourceValues(context, inputSource, flags)
+	}
+}
+
+// ApplyInputSourceValue applies a generic value to the flagSet if required
+func (f *GenericFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
+			value, err := isc.Generic(f.GenericFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value != nil {
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, value.String())
+				})
+			}
+		}
+	}
+
+	return nil
+}
+
+// ApplyInputSourceValue applies a StringSlice value to the flagSet if required
+func (f *StringSliceFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
+			value, err := isc.StringSlice(f.StringSliceFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value != nil {
+				var sliceValue cli.StringSlice = value
+				eachName(f.Name, func(name string) {
+					underlyingFlag := f.set.Lookup(f.Name)
+					if underlyingFlag != nil {
+						underlyingFlag.Value = &sliceValue
+					}
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a IntSlice value if required
+func (f *IntSliceFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
+			value, err := isc.IntSlice(f.IntSliceFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value != nil {
+				var sliceValue cli.IntSlice = value
+				eachName(f.Name, func(name string) {
+					underlyingFlag := f.set.Lookup(f.Name)
+					if underlyingFlag != nil {
+						underlyingFlag.Value = &sliceValue
+					}
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a Bool value to the flagSet if required
+func (f *BoolFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
+			value, err := isc.Bool(f.BoolFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value {
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, strconv.FormatBool(value))
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a BoolT value to the flagSet if required
+func (f *BoolTFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !context.IsSet(f.Name) && !isEnvVarSet(f.EnvVar) {
+			value, err := isc.BoolT(f.BoolTFlag.Name)
+			if err != nil {
+				return err
+			}
+			if !value {
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, strconv.FormatBool(value))
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a String value to the flagSet if required
+func (f *StringFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
+			value, err := isc.String(f.StringFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value != "" {
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, value)
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a int value to the flagSet if required
+func (f *IntFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
+			value, err := isc.Int(f.IntFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value > 0 {
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, strconv.FormatInt(int64(value), 10))
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a Duration value to the flagSet if required
+func (f *DurationFlag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
+			value, err := isc.Duration(f.DurationFlag.Name)
+			if err != nil {
+				return err
+			}
+			if value > 0 {
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, value.String())
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// ApplyInputSourceValue applies a Float64 value to the flagSet if required
+func (f *Float64Flag) ApplyInputSourceValue(context *cli.Context, isc InputSourceContext) error {
+	if f.set != nil {
+		if !(context.IsSet(f.Name) || isEnvVarSet(f.EnvVar)) {
+			value, err := isc.Float64(f.Float64Flag.Name)
+			if err != nil {
+				return err
+			}
+			if value > 0 {
+				floatStr := float64ToString(value)
+				eachName(f.Name, func(name string) {
+					f.set.Set(f.Name, floatStr)
+				})
+			}
+		}
+	}
+	return nil
+}
+
+func isEnvVarSet(envVars string) bool {
+	for _, envVar := range strings.Split(envVars, ",") {
+		envVar = strings.TrimSpace(envVar)
+		if _, ok := syscall.Getenv(envVar); ok {
+			// TODO: Can't use this for bools as
+			// set means that it was true or false based on
+			// Bool flag type, should work for other types
+			return true
+		}
+	}
+
+	return false
+}
+
+func float64ToString(f float64) string {
+	return fmt.Sprintf("%v", f)
+}
+
+func eachName(longName string, fn func(string)) {
+	parts := strings.Split(longName, ",")
+	for _, name := range parts {
+		name = strings.Trim(name, " ")
+		fn(name)
+	}
+}

vendor/github.com/minio/cli/altsrc/flag_generated.go

@@ -0,0 +1,347 @@
+package altsrc
+
+import (
+	"flag"
+
+	"gopkg.in/urfave/cli.v1"
+)
+
+// WARNING: This file is generated!
+
+// BoolFlag is the flag type that wraps cli.BoolFlag to allow
+// for other values to be specified
+type BoolFlag struct {
+	cli.BoolFlag
+	set *flag.FlagSet
+}
+
+// NewBoolFlag creates a new BoolFlag
+func NewBoolFlag(fl cli.BoolFlag) *BoolFlag {
+	return &BoolFlag{BoolFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped BoolFlag.Apply
+func (f *BoolFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.BoolFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped BoolFlag.ApplyWithError
+func (f *BoolFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.BoolFlag.ApplyWithError(set)
+}
+
+// BoolTFlag is the flag type that wraps cli.BoolTFlag to allow
+// for other values to be specified
+type BoolTFlag struct {
+	cli.BoolTFlag
+	set *flag.FlagSet
+}
+
+// NewBoolTFlag creates a new BoolTFlag
+func NewBoolTFlag(fl cli.BoolTFlag) *BoolTFlag {
+	return &BoolTFlag{BoolTFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped BoolTFlag.Apply
+func (f *BoolTFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.BoolTFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped BoolTFlag.ApplyWithError
+func (f *BoolTFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.BoolTFlag.ApplyWithError(set)
+}
+
+// DurationFlag is the flag type that wraps cli.DurationFlag to allow
+// for other values to be specified
+type DurationFlag struct {
+	cli.DurationFlag
+	set *flag.FlagSet
+}
+
+// NewDurationFlag creates a new DurationFlag
+func NewDurationFlag(fl cli.DurationFlag) *DurationFlag {
+	return &DurationFlag{DurationFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped DurationFlag.Apply
+func (f *DurationFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.DurationFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped DurationFlag.ApplyWithError
+func (f *DurationFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.DurationFlag.ApplyWithError(set)
+}
+
+// Float64Flag is the flag type that wraps cli.Float64Flag to allow
+// for other values to be specified
+type Float64Flag struct {
+	cli.Float64Flag
+	set *flag.FlagSet
+}
+
+// NewFloat64Flag creates a new Float64Flag
+func NewFloat64Flag(fl cli.Float64Flag) *Float64Flag {
+	return &Float64Flag{Float64Flag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped Float64Flag.Apply
+func (f *Float64Flag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.Float64Flag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped Float64Flag.ApplyWithError
+func (f *Float64Flag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.Float64Flag.ApplyWithError(set)
+}
+
+// GenericFlag is the flag type that wraps cli.GenericFlag to allow
+// for other values to be specified
+type GenericFlag struct {
+	cli.GenericFlag
+	set *flag.FlagSet
+}
+
+// NewGenericFlag creates a new GenericFlag
+func NewGenericFlag(fl cli.GenericFlag) *GenericFlag {
+	return &GenericFlag{GenericFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped GenericFlag.Apply
+func (f *GenericFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.GenericFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped GenericFlag.ApplyWithError
+func (f *GenericFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.GenericFlag.ApplyWithError(set)
+}
+
+// Int64Flag is the flag type that wraps cli.Int64Flag to allow
+// for other values to be specified
+type Int64Flag struct {
+	cli.Int64Flag
+	set *flag.FlagSet
+}
+
+// NewInt64Flag creates a new Int64Flag
+func NewInt64Flag(fl cli.Int64Flag) *Int64Flag {
+	return &Int64Flag{Int64Flag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped Int64Flag.Apply
+func (f *Int64Flag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.Int64Flag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped Int64Flag.ApplyWithError
+func (f *Int64Flag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.Int64Flag.ApplyWithError(set)
+}
+
+// IntFlag is the flag type that wraps cli.IntFlag to allow
+// for other values to be specified
+type IntFlag struct {
+	cli.IntFlag
+	set *flag.FlagSet
+}
+
+// NewIntFlag creates a new IntFlag
+func NewIntFlag(fl cli.IntFlag) *IntFlag {
+	return &IntFlag{IntFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped IntFlag.Apply
+func (f *IntFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.IntFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped IntFlag.ApplyWithError
+func (f *IntFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.IntFlag.ApplyWithError(set)
+}
+
+// IntSliceFlag is the flag type that wraps cli.IntSliceFlag to allow
+// for other values to be specified
+type IntSliceFlag struct {
+	cli.IntSliceFlag
+	set *flag.FlagSet
+}
+
+// NewIntSliceFlag creates a new IntSliceFlag
+func NewIntSliceFlag(fl cli.IntSliceFlag) *IntSliceFlag {
+	return &IntSliceFlag{IntSliceFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped IntSliceFlag.Apply
+func (f *IntSliceFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.IntSliceFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped IntSliceFlag.ApplyWithError
+func (f *IntSliceFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.IntSliceFlag.ApplyWithError(set)
+}
+
+// Int64SliceFlag is the flag type that wraps cli.Int64SliceFlag to allow
+// for other values to be specified
+type Int64SliceFlag struct {
+	cli.Int64SliceFlag
+	set *flag.FlagSet
+}
+
+// NewInt64SliceFlag creates a new Int64SliceFlag
+func NewInt64SliceFlag(fl cli.Int64SliceFlag) *Int64SliceFlag {
+	return &Int64SliceFlag{Int64SliceFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped Int64SliceFlag.Apply
+func (f *Int64SliceFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.Int64SliceFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped Int64SliceFlag.ApplyWithError
+func (f *Int64SliceFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.Int64SliceFlag.ApplyWithError(set)
+}
+
+// StringFlag is the flag type that wraps cli.StringFlag to allow
+// for other values to be specified
+type StringFlag struct {
+	cli.StringFlag
+	set *flag.FlagSet
+}
+
+// NewStringFlag creates a new StringFlag
+func NewStringFlag(fl cli.StringFlag) *StringFlag {
+	return &StringFlag{StringFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped StringFlag.Apply
+func (f *StringFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.StringFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped StringFlag.ApplyWithError
+func (f *StringFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.StringFlag.ApplyWithError(set)
+}
+
+// StringSliceFlag is the flag type that wraps cli.StringSliceFlag to allow
+// for other values to be specified
+type StringSliceFlag struct {
+	cli.StringSliceFlag
+	set *flag.FlagSet
+}
+
+// NewStringSliceFlag creates a new StringSliceFlag
+func NewStringSliceFlag(fl cli.StringSliceFlag) *StringSliceFlag {
+	return &StringSliceFlag{StringSliceFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped StringSliceFlag.Apply
+func (f *StringSliceFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.StringSliceFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped StringSliceFlag.ApplyWithError
+func (f *StringSliceFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.StringSliceFlag.ApplyWithError(set)
+}
+
+// Uint64Flag is the flag type that wraps cli.Uint64Flag to allow
+// for other values to be specified
+type Uint64Flag struct {
+	cli.Uint64Flag
+	set *flag.FlagSet
+}
+
+// NewUint64Flag creates a new Uint64Flag
+func NewUint64Flag(fl cli.Uint64Flag) *Uint64Flag {
+	return &Uint64Flag{Uint64Flag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped Uint64Flag.Apply
+func (f *Uint64Flag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.Uint64Flag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped Uint64Flag.ApplyWithError
+func (f *Uint64Flag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.Uint64Flag.ApplyWithError(set)
+}
+
+// UintFlag is the flag type that wraps cli.UintFlag to allow
+// for other values to be specified
+type UintFlag struct {
+	cli.UintFlag
+	set *flag.FlagSet
+}
+
+// NewUintFlag creates a new UintFlag
+func NewUintFlag(fl cli.UintFlag) *UintFlag {
+	return &UintFlag{UintFlag: fl, set: nil}
+}
+
+// Apply saves the flagSet for later usage calls, then calls the
+// wrapped UintFlag.Apply
+func (f *UintFlag) Apply(set *flag.FlagSet) {
+	f.set = set
+	f.UintFlag.Apply(set)
+}
+
+// ApplyWithError saves the flagSet for later usage calls, then calls the
+// wrapped UintFlag.ApplyWithError
+func (f *UintFlag) ApplyWithError(set *flag.FlagSet) error {
+	f.set = set
+	return f.UintFlag.ApplyWithError(set)
+}

vendor/github.com/minio/cli/altsrc/input_source_context.go

@@ -0,0 +1,21 @@
+package altsrc
+
+import (
+	"time"
+
+	"gopkg.in/urfave/cli.v1"
+)
+
+// InputSourceContext is an interface used to allow
+// other input sources to be implemented as needed.
+type InputSourceContext interface {
+	Int(name string) (int, error)
+	Duration(name string) (time.Duration, error)
+	Float64(name string) (float64, error)
+	String(name string) (string, error)
+	StringSlice(name string) ([]string, error)
+	IntSlice(name string) ([]int, error)
+	Generic(name string) (cli.Generic, error)
+	Bool(name string) (bool, error)
+	BoolT(name string) (bool, error)
+}

vendor/github.com/minio/cli/altsrc/map_input_source.go

@@ -0,0 +1,262 @@
+package altsrc
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"time"
+
+	"gopkg.in/urfave/cli.v1"
+)
+
+// MapInputSource implements InputSourceContext to return
+// data from the map that is loaded.
+type MapInputSource struct {
+	valueMap map[interface{}]interface{}
+}
+
+// nestedVal checks if the name has '.' delimiters.
+// If so, it tries to traverse the tree by the '.' delimited sections to find
+// a nested value for the key.
+func nestedVal(name string, tree map[interface{}]interface{}) (interface{}, bool) {
+	if sections := strings.Split(name, "."); len(sections) > 1 {
+		node := tree
+		for _, section := range sections[:len(sections)-1] {
+			if child, ok := node[section]; !ok {
+				return nil, false
+			} else {
+				if ctype, ok := child.(map[interface{}]interface{}); !ok {
+					return nil, false
+				} else {
+					node = ctype
+				}
+			}
+		}
+		if val, ok := node[sections[len(sections)-1]]; ok {
+			return val, true
+		}
+	}
+	return nil, false
+}
+
+// Int returns an int from the map if it exists otherwise returns 0
+func (fsm *MapInputSource) Int(name string) (int, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(int)
+		if !isType {
+			return 0, incorrectTypeForFlagError(name, "int", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(int)
+		if !isType {
+			return 0, incorrectTypeForFlagError(name, "int", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return 0, nil
+}
+
+// Duration returns a duration from the map if it exists otherwise returns 0
+func (fsm *MapInputSource) Duration(name string) (time.Duration, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(time.Duration)
+		if !isType {
+			return 0, incorrectTypeForFlagError(name, "duration", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(time.Duration)
+		if !isType {
+			return 0, incorrectTypeForFlagError(name, "duration", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return 0, nil
+}
+
+// Float64 returns an float64 from the map if it exists otherwise returns 0
+func (fsm *MapInputSource) Float64(name string) (float64, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(float64)
+		if !isType {
+			return 0, incorrectTypeForFlagError(name, "float64", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(float64)
+		if !isType {
+			return 0, incorrectTypeForFlagError(name, "float64", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return 0, nil
+}
+
+// String returns a string from the map if it exists otherwise returns an empty string
+func (fsm *MapInputSource) String(name string) (string, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(string)
+		if !isType {
+			return "", incorrectTypeForFlagError(name, "string", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(string)
+		if !isType {
+			return "", incorrectTypeForFlagError(name, "string", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return "", nil
+}
+
+// StringSlice returns an []string from the map if it exists otherwise returns nil
+func (fsm *MapInputSource) StringSlice(name string) ([]string, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if !exists {
+		otherGenericValue, exists = nestedVal(name, fsm.valueMap)
+		if !exists {
+			return nil, nil
+		}
+	}
+
+	otherValue, isType := otherGenericValue.([]interface{})
+	if !isType {
+		return nil, incorrectTypeForFlagError(name, "[]interface{}", otherGenericValue)
+	}
+
+	var stringSlice = make([]string, 0, len(otherValue))
+	for i, v := range otherValue {
+		stringValue, isType := v.(string)
+
+		if !isType {
+			return nil, incorrectTypeForFlagError(fmt.Sprintf("%s[%d]", name, i), "string", v)
+		}
+
+		stringSlice = append(stringSlice, stringValue)
+	}
+
+	return stringSlice, nil
+}
+
+// IntSlice returns an []int from the map if it exists otherwise returns nil
+func (fsm *MapInputSource) IntSlice(name string) ([]int, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if !exists {
+		otherGenericValue, exists = nestedVal(name, fsm.valueMap)
+		if !exists {
+			return nil, nil
+		}
+	}
+
+	otherValue, isType := otherGenericValue.([]interface{})
+	if !isType {
+		return nil, incorrectTypeForFlagError(name, "[]interface{}", otherGenericValue)
+	}
+
+	var intSlice = make([]int, 0, len(otherValue))
+	for i, v := range otherValue {
+		intValue, isType := v.(int)
+
+		if !isType {
+			return nil, incorrectTypeForFlagError(fmt.Sprintf("%s[%d]", name, i), "int", v)
+		}
+
+		intSlice = append(intSlice, intValue)
+	}
+
+	return intSlice, nil
+}
+
+// Generic returns an cli.Generic from the map if it exists otherwise returns nil
+func (fsm *MapInputSource) Generic(name string) (cli.Generic, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(cli.Generic)
+		if !isType {
+			return nil, incorrectTypeForFlagError(name, "cli.Generic", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(cli.Generic)
+		if !isType {
+			return nil, incorrectTypeForFlagError(name, "cli.Generic", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return nil, nil
+}
+
+// Bool returns an bool from the map otherwise returns false
+func (fsm *MapInputSource) Bool(name string) (bool, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(bool)
+		if !isType {
+			return false, incorrectTypeForFlagError(name, "bool", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(bool)
+		if !isType {
+			return false, incorrectTypeForFlagError(name, "bool", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return false, nil
+}
+
+// BoolT returns an bool from the map otherwise returns true
+func (fsm *MapInputSource) BoolT(name string) (bool, error) {
+	otherGenericValue, exists := fsm.valueMap[name]
+	if exists {
+		otherValue, isType := otherGenericValue.(bool)
+		if !isType {
+			return true, incorrectTypeForFlagError(name, "bool", otherGenericValue)
+		}
+		return otherValue, nil
+	}
+	nestedGenericValue, exists := nestedVal(name, fsm.valueMap)
+	if exists {
+		otherValue, isType := nestedGenericValue.(bool)
+		if !isType {
+			return true, incorrectTypeForFlagError(name, "bool", nestedGenericValue)
+		}
+		return otherValue, nil
+	}
+
+	return true, nil
+}
+
+func incorrectTypeForFlagError(name, expectedTypeName string, value interface{}) error {
+	valueType := reflect.TypeOf(value)
+	valueTypeName := ""
+	if valueType != nil {
+		valueTypeName = valueType.Name()
+	}
+
+	return fmt.Errorf("Mismatched type for flag '%s'. Expected '%s' but actual is '%s'", name, expectedTypeName, valueTypeName)
+}

vendor/github.com/minio/cli/altsrc/toml_file_loader.go

@@ -0,0 +1,113 @@
+// Disabling building of toml support in cases where golang is 1.0 or 1.1
+// as the encoding library is not implemented or supported.
+
+// +build go1.2
+
+package altsrc
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/BurntSushi/toml"
+	"gopkg.in/urfave/cli.v1"
+)
+
+type tomlMap struct {
+	Map map[interface{}]interface{}
+}
+
+func unmarshalMap(i interface{}) (ret map[interface{}]interface{}, err error) {
+	ret = make(map[interface{}]interface{})
+	m := i.(map[string]interface{})
+	for key, val := range m {
+		v := reflect.ValueOf(val)
+		switch v.Kind() {
+		case reflect.Bool:
+			ret[key] = val.(bool)
+		case reflect.String:
+			ret[key] = val.(string)
+		case reflect.Int:
+			ret[key] = int(val.(int))
+		case reflect.Int8:
+			ret[key] = int(val.(int8))
+		case reflect.Int16:
+			ret[key] = int(val.(int16))
+		case reflect.Int32:
+			ret[key] = int(val.(int32))
+		case reflect.Int64:
+			ret[key] = int(val.(int64))
+		case reflect.Uint:
+			ret[key] = int(val.(uint))
+		case reflect.Uint8:
+			ret[key] = int(val.(uint8))
+		case reflect.Uint16:
+			ret[key] = int(val.(uint16))
+		case reflect.Uint32:
+			ret[key] = int(val.(uint32))
+		case reflect.Uint64:
+			ret[key] = int(val.(uint64))
+		case reflect.Float32:
+			ret[key] = float64(val.(float32))
+		case reflect.Float64:
+			ret[key] = float64(val.(float64))
+		case reflect.Map:
+			if tmp, err := unmarshalMap(val); err == nil {
+				ret[key] = tmp
+			} else {
+				return nil, err
+			}
+		case reflect.Array, reflect.Slice:
+			ret[key] = val.([]interface{})
+		default:
+			return nil, fmt.Errorf("Unsupported: type = %#v", v.Kind())
+		}
+	}
+	return ret, nil
+}
+
+func (self *tomlMap) UnmarshalTOML(i interface{}) error {
+	if tmp, err := unmarshalMap(i); err == nil {
+		self.Map = tmp
+	} else {
+		return err
+	}
+	return nil
+}
+
+type tomlSourceContext struct {
+	FilePath string
+}
+
+// NewTomlSourceFromFile creates a new TOML InputSourceContext from a filepath.
+func NewTomlSourceFromFile(file string) (InputSourceContext, error) {
+	tsc := &tomlSourceContext{FilePath: file}
+	var results tomlMap = tomlMap{}
+	if err := readCommandToml(tsc.FilePath, &results); err != nil {
+		return nil, fmt.Errorf("Unable to load TOML file '%s': inner error: \n'%v'", tsc.FilePath, err.Error())
+	}
+	return &MapInputSource{valueMap: results.Map}, nil
+}
+
+// NewTomlSourceFromFlagFunc creates a new TOML InputSourceContext from a provided flag name and source context.
+func NewTomlSourceFromFlagFunc(flagFileName string) func(context *cli.Context) (InputSourceContext, error) {
+	return func(context *cli.Context) (InputSourceContext, error) {
+		filePath := context.String(flagFileName)
+		return NewTomlSourceFromFile(filePath)
+	}
+}
+
+func readCommandToml(filePath string, container interface{}) (err error) {
+	b, err := loadDataFrom(filePath)
+	if err != nil {
+		return err
+	}
+
+	err = toml.Unmarshal(b, container)
+	if err != nil {
+		return err
+	}
+
+	err = nil
+	return
+}

vendor/github.com/minio/cli/altsrc/yaml_file_loader.go

@@ -0,0 +1,92 @@
+// Disabling building of yaml support in cases where golang is 1.0 or 1.1
+// as the encoding library is not implemented or supported.
+
+// +build go1.2
+
+package altsrc
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"os"
+	"runtime"
+	"strings"
+
+	"gopkg.in/urfave/cli.v1"
+
+	"gopkg.in/yaml.v2"
+)
+
+type yamlSourceContext struct {
+	FilePath string
+}
+
+// NewYamlSourceFromFile creates a new Yaml InputSourceContext from a filepath.
+func NewYamlSourceFromFile(file string) (InputSourceContext, error) {
+	ysc := &yamlSourceContext{FilePath: file}
+	var results map[interface{}]interface{}
+	err := readCommandYaml(ysc.FilePath, &results)
+	if err != nil {
+		return nil, fmt.Errorf("Unable to load Yaml file '%s': inner error: \n'%v'", ysc.FilePath, err.Error())
+	}
+
+	return &MapInputSource{valueMap: results}, nil
+}
+
+// NewYamlSourceFromFlagFunc creates a new Yaml InputSourceContext from a provided flag name and source context.
+func NewYamlSourceFromFlagFunc(flagFileName string) func(context *cli.Context) (InputSourceContext, error) {
+	return func(context *cli.Context) (InputSourceContext, error) {
+		filePath := context.String(flagFileName)
+		return NewYamlSourceFromFile(filePath)
+	}
+}
+
+func readCommandYaml(filePath string, container interface{}) (err error) {
+	b, err := loadDataFrom(filePath)
+	if err != nil {
+		return err
+	}
+
+	err = yaml.Unmarshal(b, container)
+	if err != nil {
+		return err
+	}
+
+	err = nil
+	return
+}
+
+func loadDataFrom(filePath string) ([]byte, error) {
+	u, err := url.Parse(filePath)
+	if err != nil {
+		return nil, err
+	}
+
+	if u.Host != "" { // i have a host, now do i support the scheme?
+		switch u.Scheme {
+		case "http", "https":
+			res, err := http.Get(filePath)
+			if err != nil {
+				return nil, err
+			}
+			return ioutil.ReadAll(res.Body)
+		default:
+			return nil, fmt.Errorf("scheme of %s is unsupported", filePath)
+		}
+	} else if u.Path != "" { // i dont have a host, but I have a path. I am a local file.
+		if _, notFoundFileErr := os.Stat(filePath); notFoundFileErr != nil {
+			return nil, fmt.Errorf("Cannot read from file: '%s' because it does not exist.", filePath)
+		}
+		return ioutil.ReadFile(filePath)
+	} else if runtime.GOOS == "windows" && strings.Contains(u.String(), "\\") {
+		// on Windows systems u.Path is always empty, so we need to check the string directly.
+		if _, notFoundFileErr := os.Stat(filePath); notFoundFileErr != nil {
+			return nil, fmt.Errorf("Cannot read from file: '%s' because it does not exist.", filePath)
+		}
+		return ioutil.ReadFile(filePath)
+	} else {
+		return nil, fmt.Errorf("unable to determine how to load from path %s", filePath)
+	}
+}