mirror of https://github.com/k3s-io/k3s
152 lines
3.8 KiB
Go
152 lines
3.8 KiB
Go
/*
|
|
Copyright 2016 The Kubernetes Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package config
|
|
|
|
import (
|
|
"fmt"
|
|
"sort"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/golang/glog"
|
|
"github.com/spf13/pflag"
|
|
)
|
|
|
|
const (
|
|
flagName = "feature-gates"
|
|
|
|
// All known feature keys
|
|
// To add a new feature, define a key for it below and add
|
|
// a featureInfo entry to knownFeatures.
|
|
|
|
// allAlpha is a global toggle for alpha features. Per feature key
|
|
// values override the default set by allAlpha.
|
|
// e.g. allAlpha=false,newFeature=true will result in newFeature=true
|
|
allAlpha = "allAlpha"
|
|
)
|
|
|
|
var (
|
|
// DefaultFeatureGate is a shared global FeatureGate.
|
|
DefaultFeatureGate = &featureGate{}
|
|
|
|
// Default values for recorded features.
|
|
knownFeatures = map[string]featureInfo{
|
|
allAlpha: {false, alpha},
|
|
}
|
|
|
|
alpha = prerelease("ALPHA")
|
|
beta = prerelease("BETA")
|
|
ga = prerelease("")
|
|
)
|
|
|
|
type prerelease string
|
|
|
|
type featureInfo struct {
|
|
enabled bool
|
|
prerelease prerelease
|
|
}
|
|
|
|
// FeatureGate parses and stores flag gates for known features from
|
|
// a string like feature1=true,feature2=false,...
|
|
type FeatureGate interface {
|
|
AddFlag(fs *pflag.FlagSet)
|
|
// owner: @jlowdermilk
|
|
// alpha: v1.4
|
|
AllAlpha() bool
|
|
// TODO: Define accessors for each non-API alpha feature.
|
|
}
|
|
|
|
// featureGate implements FeatureGate as well as pflag.Value for flag parsing.
|
|
type featureGate struct {
|
|
features map[string]bool
|
|
}
|
|
|
|
// Set, String, and Type implement pflag.Value
|
|
|
|
// Set Parses a string of the form // "key1=value1,key2=value2,..." into a
|
|
// map[string]bool of known keys or returns an error.
|
|
func (f *featureGate) Set(value string) error {
|
|
f.features = make(map[string]bool)
|
|
for _, s := range strings.Split(value, ",") {
|
|
if len(s) == 0 {
|
|
continue
|
|
}
|
|
arr := strings.SplitN(s, "=", 2)
|
|
k := strings.TrimSpace(arr[0])
|
|
_, ok := knownFeatures[k]
|
|
if !ok {
|
|
return fmt.Errorf("unrecognized key: %s", k)
|
|
}
|
|
if len(arr) != 2 {
|
|
return fmt.Errorf("missing bool value for %s", k)
|
|
}
|
|
v := strings.TrimSpace(arr[1])
|
|
boolValue, err := strconv.ParseBool(v)
|
|
if err != nil {
|
|
return fmt.Errorf("invalid value of %s: %s, err: %v", k, v, err)
|
|
}
|
|
f.features[k] = boolValue
|
|
}
|
|
glog.Infof("feature gates: %v", f.features)
|
|
return nil
|
|
}
|
|
|
|
func (f *featureGate) String() string {
|
|
pairs := []string{}
|
|
for k, v := range f.features {
|
|
pairs = append(pairs, fmt.Sprintf("%s=%t", k, v))
|
|
}
|
|
sort.Strings(pairs)
|
|
return strings.Join(pairs, ",")
|
|
}
|
|
|
|
func (f *featureGate) Type() string {
|
|
return "mapStringBool"
|
|
}
|
|
|
|
// AllAlpha returns value for allAlpha.
|
|
func (f *featureGate) AllAlpha() bool {
|
|
return f.lookup(allAlpha)
|
|
}
|
|
|
|
func (f *featureGate) lookup(key string) bool {
|
|
defaultValue := knownFeatures[key].enabled
|
|
if f.features == nil {
|
|
panic(fmt.Sprintf("--%s has not been parsed", flagName))
|
|
}
|
|
if v, ok := f.features[key]; ok {
|
|
return v
|
|
}
|
|
return defaultValue
|
|
|
|
}
|
|
|
|
// AddFlag adds a flag for setting global feature gates to the specified FlagSet.
|
|
func (f *featureGate) AddFlag(fs *pflag.FlagSet) {
|
|
var known []string
|
|
for k, v := range knownFeatures {
|
|
pre := ""
|
|
if v.prerelease != ga {
|
|
pre = fmt.Sprintf("%s - ", v.prerelease)
|
|
}
|
|
known = append(known, fmt.Sprintf("%s=true|false (%sdefault=%t)", k, pre, v.enabled))
|
|
}
|
|
fs.Var(f, flagName, ""+
|
|
"A set of key=value pairs that describe feature gates for alpha/experimental features. "+
|
|
"Options are:\n"+strings.Join(known, "\n"))
|
|
}
|