gvkparser.go

Documentation: k8s.io/apimachinery/pkg/util/managedfields

     1  /*
     2  Copyright 2018 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 managedfields
    18  
    19  import (
    20  	"fmt"
    21  
    22  	"k8s.io/apimachinery/pkg/runtime/schema"
    23  	"k8s.io/kube-openapi/pkg/schemaconv"
    24  	"k8s.io/kube-openapi/pkg/util/proto"
    25  	smdschema "sigs.k8s.io/structured-merge-diff/v4/schema"
    26  	"sigs.k8s.io/structured-merge-diff/v4/typed"
    27  )
    28  
    29  // groupVersionKindExtensionKey is the key used to lookup the
    30  // GroupVersionKind value for an object definition from the
    31  // definition's "extensions" map.
    32  const groupVersionKindExtensionKey = "x-kubernetes-group-version-kind"
    33  
    34  // GvkParser contains a Parser that allows introspecting the schema.
    35  type GvkParser struct {
    36  	gvks   map[schema.GroupVersionKind]string
    37  	parser typed.Parser
    38  }
    39  
    40  // Type returns a helper which can produce objects of the given type. Any
    41  // errors are deferred until a further function is called.
    42  func (p *GvkParser) Type(gvk schema.GroupVersionKind) *typed.ParseableType {
    43  	typeName, ok := p.gvks[gvk]
    44  	if !ok {
    45  		return nil
    46  	}
    47  	t := p.parser.Type(typeName)
    48  	return &t
    49  }
    50  
    51  // NewGVKParser builds a GVKParser from a proto.Models. This
    52  // will automatically find the proper version of the object, and the
    53  // corresponding schema information.
    54  func NewGVKParser(models proto.Models, preserveUnknownFields bool) (*GvkParser, error) {
    55  	typeSchema, err := schemaconv.ToSchemaWithPreserveUnknownFields(models, preserveUnknownFields)
    56  	if err != nil {
    57  		return nil, fmt.Errorf("failed to convert models to schema: %v", err)
    58  	}
    59  	parser := GvkParser{
    60  		gvks: map[schema.GroupVersionKind]string{},
    61  	}
    62  	parser.parser = typed.Parser{Schema: smdschema.Schema{Types: typeSchema.Types}}
    63  	for _, modelName := range models.ListModels() {
    64  		model := models.LookupModel(modelName)
    65  		if model == nil {
    66  			panic(fmt.Sprintf("ListModels returns a model that can't be looked-up for: %v", modelName))
    67  		}
    68  		gvkList := parseGroupVersionKind(model)
    69  		for _, gvk := range gvkList {
    70  			if len(gvk.Kind) > 0 {
    71  				_, ok := parser.gvks[gvk]
    72  				if ok {
    73  					return nil, fmt.Errorf("duplicate entry for %v", gvk)
    74  				}
    75  				parser.gvks[gvk] = modelName
    76  			}
    77  		}
    78  	}
    79  	return &parser, nil
    80  }
    81  
    82  // Get and parse GroupVersionKind from the extension. Returns empty if it doesn't have one.
    83  func parseGroupVersionKind(s proto.Schema) []schema.GroupVersionKind {
    84  	extensions := s.GetExtensions()
    85  
    86  	gvkListResult := []schema.GroupVersionKind{}
    87  
    88  	// Get the extensions
    89  	gvkExtension, ok := extensions[groupVersionKindExtensionKey]
    90  	if !ok {
    91  		return []schema.GroupVersionKind{}
    92  	}
    93  
    94  	// gvk extension must be a list of at least 1 element.
    95  	gvkList, ok := gvkExtension.([]interface{})
    96  	if !ok {
    97  		return []schema.GroupVersionKind{}
    98  	}
    99  
   100  	for _, gvk := range gvkList {
   101  		// gvk extension list must be a map with group, version, and
   102  		// kind fields
   103  		gvkMap, ok := gvk.(map[interface{}]interface{})
   104  		if !ok {
   105  			continue
   106  		}
   107  		group, ok := gvkMap["group"].(string)
   108  		if !ok {
   109  			continue
   110  		}
   111  		version, ok := gvkMap["version"].(string)
   112  		if !ok {
   113  			continue
   114  		}
   115  		kind, ok := gvkMap["kind"].(string)
   116  		if !ok {
   117  			continue
   118  		}
   119  
   120  		gvkListResult = append(gvkListResult, schema.GroupVersionKind{
   121  			Group:   group,
   122  			Version: version,
   123  			Kind:    kind,
   124  		})
   125  	}
   126  
   127  	return gvkListResult
   128  }
   129
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