github.com/jingruilea/kubeedge@v1.2.0-beta.0.0.20200410162146-4bb8902b3879/pkg/version/verflag/verflag.go (about)

     1  /*
     2  Copyright 2014 The Kubernetes Authors.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  // Package verflag defines utility functions to handle command line flags
    18  // related to version of Kubernetes.
    19  package verflag
    20  
    21  import (
    22  	"fmt"
    23  	"os"
    24  	"strconv"
    25  
    26  	"github.com/kubeedge/kubeedge/pkg/version"
    27  
    28  	flag "github.com/spf13/pflag"
    29  )
    30  
    31  type versionValue int
    32  
    33  const (
    34  	VersionFalse versionValue = 0
    35  	VersionTrue  versionValue = 1
    36  	VersionRaw   versionValue = 2
    37  )
    38  
    39  const strRawVersion string = "raw"
    40  
    41  func (v *versionValue) IsBoolFlag() bool {
    42  	return true
    43  }
    44  
    45  func (v *versionValue) Get() interface{} {
    46  	return versionValue(*v)
    47  }
    48  
    49  func (v *versionValue) Set(s string) error {
    50  	if s == strRawVersion {
    51  		*v = VersionRaw
    52  		return nil
    53  	}
    54  	boolVal, err := strconv.ParseBool(s)
    55  	if boolVal {
    56  		*v = VersionTrue
    57  	} else {
    58  		*v = VersionFalse
    59  	}
    60  	return err
    61  }
    62  
    63  func (v *versionValue) String() string {
    64  	if *v == VersionRaw {
    65  		return strRawVersion
    66  	}
    67  	return fmt.Sprintf("%v", bool(*v == VersionTrue))
    68  }
    69  
    70  // The type of the flag as required by the pflag.Value interface
    71  func (v *versionValue) Type() string {
    72  	return "version"
    73  }
    74  
    75  func VersionVar(p *versionValue, name string, value versionValue, usage string) {
    76  	*p = value
    77  	flag.Var(p, name, usage)
    78  	// "--version" will be treated as "--version=true"
    79  	flag.Lookup(name).NoOptDefVal = "true"
    80  }
    81  
    82  func Version(name string, value versionValue, usage string) *versionValue {
    83  	p := new(versionValue)
    84  	VersionVar(p, name, value, usage)
    85  	return p
    86  }
    87  
    88  const versionFlagName = "version"
    89  
    90  var (
    91  	versionFlag = Version(versionFlagName, VersionFalse, "Print version information and quit")
    92  )
    93  
    94  // AddFlags registers this package's flags on arbitrary FlagSets, such that they point to the
    95  // same value as the global flags.
    96  func AddFlags(fs *flag.FlagSet) {
    97  	fs.AddFlag(flag.Lookup(versionFlagName))
    98  }
    99  
   100  // PrintAndExitIfRequested will check if the -version flag was passed
   101  // and, if so, print the version and exit.
   102  func PrintAndExitIfRequested() {
   103  	if *versionFlag == VersionRaw {
   104  		fmt.Printf("%#v\n", version.Get())
   105  		os.Exit(0)
   106  	} else if *versionFlag == VersionTrue {
   107  		fmt.Printf("KubeEdge %s\n", version.Get())
   108  		os.Exit(0)
   109  	}
   110  }