sigs.k8s.io/kubebuilder/v3@v3.14.0/pkg/plugin/version.go (about)

     1  /*
     2  Copyright 2020 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 plugin
    18  
    19  import (
    20  	"errors"
    21  	"fmt"
    22  	"strconv"
    23  	"strings"
    24  
    25  	"sigs.k8s.io/kubebuilder/v3/pkg/model/stage"
    26  )
    27  
    28  var (
    29  	errNegative = errors.New("plugin version number must be positive")
    30  	errEmpty    = errors.New("plugin version is empty")
    31  )
    32  
    33  // Version is a plugin version containing a positive integer and a stage value that represents stability.
    34  type Version struct {
    35  	// Number denotes the current version of a plugin. Two different numbers between versions
    36  	// indicate that they are incompatible.
    37  	Number int
    38  	// Stage indicates stability.
    39  	Stage stage.Stage
    40  }
    41  
    42  // Parse parses version inline, assuming it adheres to format: (v)?[0-9]*(-(alpha|beta))?
    43  func (v *Version) Parse(version string) error {
    44  	version = strings.TrimPrefix(version, "v")
    45  	if len(version) == 0 {
    46  		return errEmpty
    47  	}
    48  
    49  	substrings := strings.SplitN(version, "-", 2)
    50  
    51  	var err error
    52  	if v.Number, err = strconv.Atoi(substrings[0]); err != nil {
    53  		// Lets check if the `-` belonged to a negative number
    54  		if n, err := strconv.Atoi(version); err == nil && n < 0 {
    55  			return errNegative
    56  		}
    57  		return err
    58  	}
    59  
    60  	if len(substrings) > 1 {
    61  		if err = v.Stage.Parse(substrings[1]); err != nil {
    62  			return err
    63  		}
    64  	}
    65  
    66  	return nil
    67  }
    68  
    69  // String returns the string representation of v.
    70  func (v Version) String() string {
    71  	stageStr := v.Stage.String()
    72  	if len(stageStr) == 0 {
    73  		return fmt.Sprintf("v%d", v.Number)
    74  	}
    75  	return fmt.Sprintf("v%d-%s", v.Number, stageStr)
    76  }
    77  
    78  // Validate ensures that the version number is positive and the stage is one of the valid stages.
    79  func (v Version) Validate() error {
    80  	if v.Number < 0 {
    81  		return errNegative
    82  	}
    83  
    84  	return v.Stage.Validate()
    85  }
    86  
    87  // Compare returns -1 if v < other, 0 if v == other, and 1 if v > other.
    88  func (v Version) Compare(other Version) int {
    89  	if v.Number > other.Number {
    90  		return 1
    91  	} else if v.Number < other.Number {
    92  		return -1
    93  	}
    94  
    95  	return v.Stage.Compare(other.Stage)
    96  }
    97  
    98  // IsStable returns true if v is stable.
    99  func (v Version) IsStable() bool {
   100  	// Plugin version 0 is not considered stable
   101  	if v.Number == 0 {
   102  		return false
   103  	}
   104  
   105  	// Any other version than 0 depends on its stage field
   106  	return v.Stage.IsStable()
   107  }