workflow.go

Documentation: github.com/chaos-mesh/chaos-mesh/cmd/chaos-builder

     1  // Copyright 2021 Chaos Mesh 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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package main
    15  
    16  import (
    17  	"bytes"
    18  	"fmt"
    19  	"strings"
    20  	"text/template"
    21  
    22  	"github.com/iancoleman/strcase"
    23  )
    24  
    25  // struct workflowCodeGenerator will render content of one file contains code blocks that required by workflow
    26  type workflowCodeGenerator struct {
    27  	// name of each Kind of chaos, for example: PodChaos, IOChaos, DNSChaos
    28  	chaosTypes []string
    29  }
    30  
    31  func newWorkflowCodeGenerator(types []string) *workflowCodeGenerator {
    32  	return &workflowCodeGenerator{chaosTypes: types}
    33  }
    34  
    35  func (it *workflowCodeGenerator) AppendTypes(typeName string) {
    36  	it.chaosTypes = append(it.chaosTypes, typeName)
    37  }
    38  
    39  func (it *workflowCodeGenerator) Render() string {
    40  
    41  	workflowTemplateTypesEntries := ""
    42  	for _, item := range it.chaosTypes {
    43  		workflowTemplateTypesEntries += generateTemplateTypes(item)
    44  	}
    45  
    46  	embedChaosEntries := ""
    47  	for _, item := range it.chaosTypes {
    48  		embedChaosEntries += generateEmbedChaos(item)
    49  	}
    50  
    51  	spawnObjectMethod := ""
    52  	for _, item := range it.chaosTypes {
    53  		spawnObjectMethod += generateSpawnObjectMethodItem(item)
    54  	}
    55  	spawnListMethod := ""
    56  	for _, item := range it.chaosTypes {
    57  		spawnListMethod += generateSpawnListMethodItem(item)
    58  	}
    59  	allChaosTemplateTypeEntries := ""
    60  	for _, item := range it.chaosTypes {
    61  		allChaosTemplateTypeEntries += fmt.Sprintf(`	Type%s,
    62  `, item)
    63  	}
    64  
    65  	genericChaosListImplementations := ""
    66  	for _, item := range it.chaosTypes {
    67  		genericChaosListImplementations += generateGenericChaosList(item)
    68  	}
    69  
    70  	imports := `import (
    71  	"fmt"
    72  	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    73  	"k8s.io/apimachinery/pkg/runtime"
    74  )
    75  `
    76  
    77  	workflowTemplateTypesCodes := fmt.Sprintf(`%s
    78  
    79  %s
    80  
    81  const (
    82  %s
    83  )
    84  
    85  var allChaosTemplateType = []TemplateType{
    86  	TypeSchedule,
    87  %s
    88  }
    89  
    90  type EmbedChaos struct {
    91  %s
    92  }
    93  
    94  func (it *EmbedChaos) SpawnNewObject(templateType TemplateType) (runtime.Object, metav1.Object, error) {
    95  
    96  	switch templateType {
    97  %s
    98  	default:
    99  		return nil, nil, fmt.Errorf("unsupported template type %%s", templateType)
   100  	}
   101  
   102  	return nil, &metav1.ObjectMeta{}, nil
   103  }
   104  
   105  func (it *EmbedChaos) SpawnNewList(templateType TemplateType) (GenericChaosList, error) {
   106  
   107  	switch templateType {
   108  %s
   109  	default:
   110  		return nil, fmt.Errorf("unsupported template type %%s", templateType)
   111  	}
   112  
   113  	return nil, nil
   114  }
   115  
   116  %s
   117  `,
   118  		boilerplate,
   119  		imports,
   120  		workflowTemplateTypesEntries,
   121  		allChaosTemplateTypeEntries,
   122  		embedChaosEntries,
   123  		spawnObjectMethod,
   124  		spawnListMethod,
   125  		genericChaosListImplementations,
   126  	)
   127  
   128  	return workflowTemplateTypesCodes
   129  }
   130  
   131  const workflowTemplateTypeEntryTemplate = `	Type{{.Type}} TemplateType = "{{.Type}}"
   132  `
   133  
   134  func generateTemplateTypes(typeName string) string {
   135  	tmpl, err := template.New("workflowTemplates").Parse(workflowTemplateTypeEntryTemplate)
   136  	if err != nil {
   137  		log.Error(err, "fail to build template")
   138  		return ""
   139  	}
   140  
   141  	buf := new(bytes.Buffer)
   142  	err = tmpl.Execute(buf, &metadata{
   143  		Type: typeName,
   144  	})
   145  	if err != nil {
   146  		log.Error(err, "fail to execute template")
   147  		return ""
   148  	}
   149  
   150  	return buf.String()
   151  }
   152  
   153  const embedChaosEntryTemplate = `	// +optional
   154  	{{.Type}} *{{.Type}}Spec ` + "`" + `json:"{{.JsonField}},omitempty"` + "`" + `
   155  `
   156  
   157  func generateEmbedChaos(typeName string) string {
   158  	value := struct {
   159  		Type      string
   160  		JsonField string
   161  	}{
   162  		Type:      typeName,
   163  		JsonField: lowercaseCamelCase(typeName),
   164  	}
   165  	tmpl, err := template.New("workflowTemplates").Parse(embedChaosEntryTemplate)
   166  	if err != nil {
   167  		log.Error(err, "fail to build template")
   168  		return ""
   169  	}
   170  
   171  	buf := new(bytes.Buffer)
   172  	err = tmpl.Execute(buf, &value)
   173  	if err != nil {
   174  		log.Error(err, "fail to execute template")
   175  		return ""
   176  	}
   177  
   178  	return buf.String()
   179  }
   180  
   181  func lowercaseCamelCase(str string) string {
   182  	// here are some name thing issue about the acronyms, we used ALLCAP name in chaos kind, like DNSChaos or JVMChaos,
   183  	// library could not resolve that well, so we just manually do it.
   184  	if strings.Contains(str, "Chaos") {
   185  		position := strings.Index(str, "Chaos")
   186  		return strings.ToLower(str[:position]) + str[position:]
   187  	}
   188  	return strcase.ToLowerCamel(str)
   189  }
   190  
   191  const spawnObjectEntryTemplate = `	case Type{{.Type}}:
   192  		result := {{.Type}}{}
   193  		result.Spec = *it.{{.Type}}
   194  		return &result, result.GetObjectMeta(), nil
   195  `
   196  
   197  func generateSpawnObjectMethodItem(typeName string) string {
   198  	tmpl, err := template.New("spawnObjectEntry").Parse(spawnObjectEntryTemplate)
   199  	if err != nil {
   200  		log.Error(err, "fail to build template")
   201  		return ""
   202  	}
   203  
   204  	buf := new(bytes.Buffer)
   205  	err = tmpl.Execute(buf, &metadata{
   206  		Type: typeName,
   207  	})
   208  	if err != nil {
   209  		log.Error(err, "fail to execute template")
   210  		return ""
   211  	}
   212  
   213  	return buf.String()
   214  }
   215  
   216  const spawnListEntryTemplate = `	case Type{{.Type}}:
   217  		result := {{.Type}}List{}
   218  		return &result, nil
   219  `
   220  
   221  func generateSpawnListMethodItem(typeName string) string {
   222  	tmpl, err := template.New("fillingMethod").Parse(spawnListEntryTemplate)
   223  	if err != nil {
   224  		log.Error(err, "fail to build template")
   225  		return ""
   226  	}
   227  
   228  	buf := new(bytes.Buffer)
   229  	err = tmpl.Execute(buf, &metadata{
   230  		Type: typeName,
   231  	})
   232  	if err != nil {
   233  		log.Error(err, "fail to execute template")
   234  		return ""
   235  	}
   236  
   237  	return buf.String()
   238  }
   239  
   240  const genericChaosList = `func (in *{{.Type}}List) GetItems() []GenericChaos {
   241  	var result []GenericChaos
   242  	for _, item := range in.Items {
   243  		item := item
   244  		result = append(result, &item)
   245  	}
   246  	return result
   247  }
   248  `
   249  
   250  func generateGenericChaosList(typeName string) string {
   251  	tmpl, err := template.New("genericChaosList").Parse(genericChaosList)
   252  	if err != nil {
   253  		log.Error(err, "fail to build template")
   254  		return ""
   255  	}
   256  
   257  	buf := new(bytes.Buffer)
   258  	err = tmpl.Execute(buf, &metadata{
   259  		Type: typeName,
   260  	})
   261  	if err != nil {
   262  		log.Error(err, "fail to execute template")
   263  		return ""
   264  	}
   265  
   266  	return buf.String()
   267  }
   268