selector.go

Documentation: k8s.io/cli-runtime/pkg/resource

     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 resource
    18  
    19  import (
    20  	"k8s.io/apimachinery/pkg/api/meta"
    21  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    22  	"k8s.io/apimachinery/pkg/runtime"
    23  	"k8s.io/apimachinery/pkg/watch"
    24  )
    25  
    26  // Selector is a Visitor for resources that match a label selector.
    27  type Selector struct {
    28  	Client        RESTClient
    29  	Mapping       *meta.RESTMapping
    30  	Namespace     string
    31  	LabelSelector string
    32  	FieldSelector string
    33  	LimitChunks   int64
    34  }
    35  
    36  // NewSelector creates a resource selector which hides details of getting items by their label selector.
    37  func NewSelector(client RESTClient, mapping *meta.RESTMapping, namespace, labelSelector, fieldSelector string, limitChunks int64) *Selector {
    38  	return &Selector{
    39  		Client:        client,
    40  		Mapping:       mapping,
    41  		Namespace:     namespace,
    42  		LabelSelector: labelSelector,
    43  		FieldSelector: fieldSelector,
    44  		LimitChunks:   limitChunks,
    45  	}
    46  }
    47  
    48  // Visit implements Visitor and uses request chunking by default.
    49  func (r *Selector) Visit(fn VisitorFunc) error {
    50  	helper := NewHelper(r.Client, r.Mapping)
    51  	initialOpts := metav1.ListOptions{
    52  		LabelSelector: r.LabelSelector,
    53  		FieldSelector: r.FieldSelector,
    54  		Limit:         r.LimitChunks,
    55  	}
    56  	return FollowContinue(&initialOpts, func(options metav1.ListOptions) (runtime.Object, error) {
    57  		list, err := helper.List(
    58  			r.Namespace,
    59  			r.ResourceMapping().GroupVersionKind.GroupVersion().String(),
    60  			&options,
    61  		)
    62  		if err != nil {
    63  			return nil, EnhanceListError(err, options, r.Mapping.Resource.String())
    64  		}
    65  		resourceVersion, _ := metadataAccessor.ResourceVersion(list)
    66  
    67  		info := &Info{
    68  			Client:  r.Client,
    69  			Mapping: r.Mapping,
    70  
    71  			Namespace:       r.Namespace,
    72  			ResourceVersion: resourceVersion,
    73  
    74  			Object: list,
    75  		}
    76  
    77  		if err := fn(info, nil); err != nil {
    78  			return nil, err
    79  		}
    80  		return list, nil
    81  	})
    82  }
    83  
    84  func (r *Selector) Watch(resourceVersion string) (watch.Interface, error) {
    85  	return NewHelper(r.Client, r.Mapping).Watch(r.Namespace, r.ResourceMapping().GroupVersionKind.GroupVersion().String(),
    86  		&metav1.ListOptions{ResourceVersion: resourceVersion, LabelSelector: r.LabelSelector, FieldSelector: r.FieldSelector})
    87  }
    88  
    89  // ResourceMapping returns the mapping for this resource and implements ResourceMapping
    90  func (r *Selector) ResourceMapping() *meta.RESTMapping {
    91  	return r.Mapping
    92  }
    93
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