1/*
2Copyright 2018 The Kubernetes Authors.
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8    http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15*/
16
17package options
18
19import (
20	"flag"
21	"fmt"
22	"os"
23	"strings"
24
25	"github.com/spf13/pflag"
26
27	// libs that provide registration functions
28	"k8s.io/component-base/logs"
29	"k8s.io/component-base/version/verflag"
30	"k8s.io/klog/v2"
31
32	// ensure libs have a chance to globally register their flags
33	_ "k8s.io/kubernetes/pkg/credentialprovider/azure"
34	_ "k8s.io/kubernetes/pkg/credentialprovider/gcp"
35)
36
37// AddGlobalFlags explicitly registers flags that libraries (glog, verflag, etc.) register
38// against the global flagsets from "flag" and "github.com/spf13/pflag".
39// We do this in order to prevent unwanted flags from leaking into the Kubelet's flagset.
40func AddGlobalFlags(fs *pflag.FlagSet) {
41	addKlogFlags(fs)
42	addCadvisorFlags(fs)
43	addCredentialProviderFlags(fs)
44	verflag.AddFlags(fs)
45	logs.AddFlags(fs)
46}
47
48// normalize replaces underscores with hyphens
49// we should always use hyphens instead of underscores when registering kubelet flags
50func normalize(s string) string {
51	return strings.Replace(s, "_", "-", -1)
52}
53
54// register adds a flag to local that targets the Value associated with the Flag named globalName in global
55func register(global *flag.FlagSet, local *pflag.FlagSet, globalName string) {
56	if f := global.Lookup(globalName); f != nil {
57		pflagFlag := pflag.PFlagFromGoFlag(f)
58		pflagFlag.Name = normalize(pflagFlag.Name)
59		local.AddFlag(pflagFlag)
60	} else {
61		panic(fmt.Sprintf("failed to find flag in global flagset (flag): %s", globalName))
62	}
63}
64
65// pflagRegister adds a flag to local that targets the Value associated with the Flag named globalName in global
66func pflagRegister(global, local *pflag.FlagSet, globalName string) {
67	if f := global.Lookup(globalName); f != nil {
68		f.Name = normalize(f.Name)
69		local.AddFlag(f)
70	} else {
71		panic(fmt.Sprintf("failed to find flag in global flagset (pflag): %s", globalName))
72	}
73}
74
75// registerDeprecated registers the flag with register, and then marks it deprecated
76func registerDeprecated(global *flag.FlagSet, local *pflag.FlagSet, globalName, deprecated string) {
77	register(global, local, globalName)
78	local.Lookup(normalize(globalName)).Deprecated = deprecated
79}
80
81// addCredentialProviderFlags adds flags from k8s.io/kubernetes/pkg/credentialprovider
82func addCredentialProviderFlags(fs *pflag.FlagSet) {
83	// lookup flags in global flag set and re-register the values with our flagset
84	global := pflag.CommandLine
85	local := pflag.NewFlagSet(os.Args[0], pflag.ExitOnError)
86
87	addLegacyCloudProviderCredentialProviderFlags(global, local)
88
89	fs.AddFlagSet(local)
90}
91
92// addKlogFlags adds flags from k8s.io/klog
93func addKlogFlags(fs *pflag.FlagSet) {
94	local := flag.NewFlagSet(os.Args[0], flag.ExitOnError)
95	klog.InitFlags(local)
96	fs.AddGoFlagSet(local)
97}
98