gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/tools/gvisor_k8s_tool/provider/clusterflag/clusterflag.go (about)

     1  // Copyright 2023 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package clusterflag implements a flag.Value which can be used in commands
    16  // to represent a Kubernetes cluster.
    17  package clusterflag
    18  
    19  import (
    20  	"context"
    21  	"fmt"
    22  	"strings"
    23  
    24  	"gvisor.dev/gvisor/tools/gvisor_k8s_tool/cluster"
    25  	"gvisor.dev/gvisor/tools/gvisor_k8s_tool/provider/gke"
    26  	"gvisor.dev/gvisor/tools/gvisor_k8s_tool/provider/kubectl"
    27  )
    28  
    29  // Provider is a cluster provider.
    30  type Provider string
    31  
    32  const (
    33  	// Kubectl is a provider using a local kubectl config.
    34  	Kubectl Provider = "kube"
    35  
    36  	// GKE is a provider using GKE.
    37  	GKE Provider = "gke"
    38  )
    39  
    40  // String returns the provider name.
    41  func (p Provider) String() string {
    42  	return string(p)
    43  }
    44  
    45  // Valid returns whether the Provider is valid.
    46  func (p Provider) Valid() bool {
    47  	switch p {
    48  	case Kubectl, GKE:
    49  		return true
    50  	default:
    51  		return false
    52  	}
    53  }
    54  
    55  // ValidInfo validates whether the given info is valid for this provider.
    56  func (p Provider) ValidInfo(info string) error {
    57  	switch p {
    58  	case Kubectl:
    59  		return nil
    60  	case GKE:
    61  		_, err := gke.NewClusterURL(info)
    62  		return err
    63  	default:
    64  		return fmt.Errorf("invalid provider: %q", p)
    65  	}
    66  }
    67  
    68  // Flag contains the necessary information to connect to a Kubernetes cluster.
    69  // Flag implements flag.Value.
    70  type Flag struct {
    71  	StringVal string
    72  	Provider  Provider
    73  	Info      string
    74  }
    75  
    76  // Valid checks if the flag values are valid.
    77  func (f *Flag) Valid() error {
    78  	if !f.Provider.Valid() {
    79  		return fmt.Errorf("invalid provider: %q", f.Provider)
    80  	}
    81  	if err := f.Provider.ValidInfo(f.Info); err != nil {
    82  		return fmt.Errorf("invalid info for provider %q: %w", f.Provider, err)
    83  	}
    84  	return nil
    85  }
    86  
    87  // String implements flag.Value.String.
    88  func (f *Flag) String() string {
    89  	return f.StringVal
    90  }
    91  
    92  // Get implements flag.Value.Get.
    93  func (f *Flag) Get() any {
    94  	return f
    95  }
    96  
    97  // Set implements flag.Value.Set.
    98  // Set(String()) should be idempotent.
    99  func (f *Flag) Set(s string) error {
   100  	f.StringVal = s
   101  	parts := strings.SplitN(s, ":", 2)
   102  	if len(parts) != 2 {
   103  		return fmt.Errorf("invalid format: %q (expected <provider>:<info>)", s)
   104  	}
   105  	f2 := Flag{
   106  		StringVal: s,
   107  		Provider:  Provider(parts[0]),
   108  		Info:      parts[1],
   109  	}
   110  	if err := f2.Valid(); err != nil {
   111  		return err
   112  	}
   113  	f.Provider = f2.Provider
   114  	f.Info = f2.Info
   115  	return nil
   116  }
   117  
   118  // Cluster creates a cluster client.
   119  func (f *Flag) Cluster(ctx context.Context) (*cluster.Cluster, error) {
   120  	switch f.Provider {
   121  	case Kubectl:
   122  		return kubectl.NewCluster(f.Info)
   123  	case GKE:
   124  		clusterURL, err := gke.NewClusterURL(f.Info)
   125  		if err != nil {
   126  			return nil, err
   127  		}
   128  		return gke.GetCluster(ctx, clusterURL)
   129  	default:
   130  		return nil, fmt.Errorf("invalid provider: %q", f.Provider)
   131  	}
   132  }