[Feature Flagging] GO Feature Flag

개요

• 사이트/GitHub
• OpenFeature를 만족하는 프로바이더
• OpenFeature SDK 또는 GO module로 사용

Feature Flag 구성

• 구성 접근방식
  • YAML, TOML or JSON
  • S3, Google Cloud Storage, Github, HTTP, Kubernetes config maps, Local file …
• 구성 포맷
  • 에디터
  • 포맷
  • 예시
    • YAML

      •  # This is your configuration for your first flag
         first-flag:
           variations: # All possible return value for your feature flag
             A: false
             B: true
           targeting: # If you want to target a subset of your users in particular
             - query: key eq "random-key"
               percentage:
                 A: 0
                 B: 100
           defaultRule: # When no targeting match we use the defaultRule
             variation: A
           metadata:
             issue_link: https://github.com/thomaspoignant/go-feature-flag/issues/XXX
             description: this is my first feature flag
        

• 배포 전략
  • Canary Release
  • Experimentation rollout, A/B Testing
  • Progressive rollout
  • Scheduled rollout
• 사용 데이터 수집
  • format : parquet, JSON or CSV
  • exporters

예제

• flags.yaml

  •  flag-1:
       variations:
         Variation_1: true
         Variation_2: false
       targeting:
         - name: Rule 1
           query: key eq "key-1"
           variation: Variation_1
       defaultRule:
         variation: Variation_2
    

• OpenFeature SDK
  • Go
    • 코드

      •  package main
                    
         import (
             "context"
             "strconv"
             "time"
                    
             gofeatureflag "github.com/open-feature/go-sdk-contrib/providers/go-feature-flag/pkg"
             "github.com/open-feature/go-sdk/openfeature"
             ffclient "github.com/thomaspoignant/go-feature-flag"
             "github.com/thomaspoignant/go-feature-flag/retriever/fileretriever"
         )
                    
         func getProvider() (openfeature.FeatureProvider, error) {
             options := gofeatureflag.ProviderOptions{
                 GOFeatureFlagConfig: &ffclient.Config{
                     PollingInterval: 10 * time.Second,
                     Context:         context.Background(),
                     Retriever: &fileretriever.Retriever{
                         Path: "./flags.yaml",
                     },
                 },
             }
             return gofeatureflag.NewProvider(options)
         }
                    
         func main() {
             if provider, err := getProvider(); err != nil {
                 panic(err)
             } else if err := openfeature.SetProvider(provider); err != nil {
                 panic(err)
             }
                    
             client := openfeature.NewClient("application name")
             defer openfeature.Shutdown()
                    
             for i := 0; i < 5; i++ {
                 key := "key-" + strconv.Itoa(i)
                 evaluationContext := openfeature.NewEvaluationContext(key, nil)
                    
                 if value, err := client.BooleanValue(context.TODO(), "flag-1", true, evaluationContext); err != nil {
                     panic(err)
                 } else {
                     println(key, "-", value)
                 }
             }
         }
        

    • 실행 결과

       key-0 - false
       key-1 - true
       key-2 - false
       key-3 - false
       key-4 - false
      

• GO module
  • Go
    • 코드

      •  package main
                    
         import (
             "context"
             "strconv"
             "time"
                    
             ffclient "github.com/thomaspoignant/go-feature-flag"
             "github.com/thomaspoignant/go-feature-flag/exporter/fileexporter"
             "github.com/thomaspoignant/go-feature-flag/ffcontext"
             "github.com/thomaspoignant/go-feature-flag/retriever/fileretriever"
         )
                    
         func main() {
             if err := ffclient.Init(ffclient.Config{
                 PollingInterval: 10 * time.Second,
                 Context:         context.Background(),
                 Retriever: &fileretriever.Retriever{
                     Path: "./flags.yaml",
                 },
                 DataExporter: ffclient.DataExporter{
                     FlushInterval:    10 * time.Second,
                     MaxEventInMemory: 100,
                     Exporter: &fileexporter.Exporter{
                         OutputDir:   "./",
                         Format:      "csv",
                         Filename:    "flag-variation--.",
                         CsvTemplate: ";;;;;;;;\n",
                     },
                 },
             }); err != nil {
                 panic(err)
             }
             defer ffclient.Close()
                    
             for i := 0; i < 5; i++ {
                 key := "key-" + strconv.Itoa(i)
                 evaluationContext := ffcontext.NewEvaluationContext(key)
                 if value, err := ffclient.BoolVariation("flag-1", evaluationContext, true); err != nil {
                     panic(err)
                 } else {
                     println(key, "-", value)
                 }
             }
         }
        

    • 실행 결과
      • 표준 출력

         key-0 - false
         key-1 - true
         key-2 - false
         key-3 - false
         key-4 - false
        

      • flag-variation-localhost.localdomain-1712026275.csv

        •  feature;user;key-0;1712026275;flag-1;Variation_2;false;false;SERVER
           feature;user;key-1;1712026275;flag-1;Variation_1;true;false;SERVER
           feature;user;key-2;1712026275;flag-1;Variation_2;false;false;SERVER
           feature;user;key-3;1712026275;flag-1;Variation_2;false;false;SERVER
           feature;user;key-4;1712026275;flag-1;Variation_2;false;false;SERVER