knative.dev/pkg@v0.0.0-20260602142205-ac97e43f6622/version/version.go (about)

     1  /*
     2  Copyright 2019 The Knative 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 version
    18  
    19  import (
    20  	"fmt"
    21  	"os"
    22  	"strings"
    23  
    24  	"github.com/blang/semver/v4"
    25  	"k8s.io/client-go/discovery"
    26  )
    27  
    28  const (
    29  	// KubernetesMinVersionKey is the environment variable that can be used to override
    30  	// the Kubernetes minimum version required by Knative.
    31  	KubernetesMinVersionKey = "KUBERNETES_MIN_VERSION"
    32  
    33  	// NOTE: If you are changing this line, please also update the minimum kubernetes
    34  	// version listed here:
    35  	// https://github.com/knative/docs/blob/main/docs/snippets/prerequisites.md
    36  
    37  	// DefaultKubernetesMinVersion is the default minimum Kubernetes version
    38  	// Knative is built and tested against. The value has a leading "v"
    39  	// (e.g. "v1.34.0").
    40  	DefaultKubernetesMinVersion = "v1.34.0"
    41  )
    42  
    43  // KubernetesMinimumVersion returns the minimum Kubernetes version required by
    44  // Knative. It returns the value of the KUBERNETES_MIN_VERSION environment
    45  // variable if set, otherwise DefaultKubernetesMinVersion.
    46  func KubernetesMinimumVersion() string {
    47  	if v := os.Getenv(KubernetesMinVersionKey); v != "" {
    48  		return v
    49  	}
    50  	return DefaultKubernetesMinVersion
    51  }
    52  
    53  // CheckMinimumVersion checks if the currently installed version of
    54  // Kubernetes is compatible with the minimum version required.
    55  // Returns an error if its not.
    56  //
    57  // A Kubernetes discovery client can be passed in as the versioner
    58  // like `CheckMinimumVersion(kubeClient.Discovery())`.
    59  func CheckMinimumVersion(versioner discovery.ServerVersionInterface) error {
    60  	v, err := versioner.ServerVersion()
    61  	if err != nil {
    62  		return err
    63  	}
    64  
    65  	currentVersion, err := semver.Make(normalizeVersion(v.GitVersion))
    66  	if err != nil {
    67  		return err
    68  	}
    69  	minimumVersion, err := semver.Make(normalizeVersion(KubernetesMinimumVersion()))
    70  	if err != nil {
    71  		return err
    72  	}
    73  
    74  	// If no specific pre-release requirement is set, we default to "-0" to always allow
    75  	// pre-release versions of the same Major.Minor.Patch version.
    76  	// Set IsNum to true otherwise currentVersion.LT() below always returns true.
    77  	if len(minimumVersion.Pre) == 0 {
    78  		minimumVersion.Pre = []semver.PRVersion{{VersionNum: 0, IsNum: true}}
    79  	}
    80  
    81  	// Return error if the current version is less than the minimum version required.
    82  	if currentVersion.LT(minimumVersion) {
    83  		return fmt.Errorf("kubernetes version %q is not compatible, need at least %q (this can be overridden with the env var %q)",
    84  			currentVersion, minimumVersion, KubernetesMinVersionKey)
    85  	}
    86  	return nil
    87  }
    88  
    89  func normalizeVersion(v string) string {
    90  	if strings.HasPrefix(v, "v") {
    91  		// No need to account for unicode widths.
    92  		return v[1:]
    93  	}
    94  	return v
    95  }