replace featureflag service with flagd

.env

@@ -62,6 +62,9 @@ FEATURE_FLAG_SERVICE_HOST=feature-flag-service
 FEATURE_FLAG_GRPC_SERVICE_PORT=50053
 FEATURE_FLAG_GRPC_SERVICE_ADDR=featureflagservice:${FEATURE_FLAG_GRPC_SERVICE_PORT}
 
+# flagd
+FLAGD_HOST=flagd
+
 # Frontend
 FRONTEND_PORT=8080
 FRONTEND_ADDR=frontend:${FRONTEND_PORT}

docker-compose.yml

@@ -62,7 +62,7 @@ services:
       - "${AD_SERVICE_PORT}"
     environment:
       - AD_SERVICE_PORT
-      - FEATURE_FLAG_GRPC_SERVICE_ADDR
+      - FLAGD_HOST
       - OTEL_EXPORTER_OTLP_ENDPOINT=http://${OTEL_COLLECTOR_HOST}:${OTEL_COLLECTOR_PORT_HTTP}
       - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
       - OTEL_RESOURCE_ATTRIBUTES
@@ -91,7 +91,7 @@ services:
       - "${CART_SERVICE_PORT}"
     environment:
       - CART_SERVICE_PORT
-      - FEATURE_FLAG_GRPC_SERVICE_ADDR
+      - FLAGD_HOST
       - REDIS_ADDR
       - OTEL_EXPORTER_OTLP_ENDPOINT
       - OTEL_RESOURCE_ATTRIBUTES
@@ -203,36 +203,20 @@ services:
         condition: service_started
     logging: *logging
 
-  # Feature Flag service
-  featureflagservice:
-    image: ${IMAGE_NAME}:${IMAGE_VERSION}-featureflagservice
-    container_name: feature-flag-service
-    build:
-      context: ./
-      dockerfile: ./src/featureflagservice/Dockerfile
-      cache_from:
-        - ${IMAGE_NAME}:${IMAGE_VERSION}-featureflagservice
-    deploy:
-      resources:
-        limits:
-          memory: 175M
-    restart: unless-stopped
+  flagd:
+    image: ghcr.io/open-feature/flagd:latest
+    container_name: flagd
+    command: [
+      "start",
+      "--uri",
+      "file:./etc/flagd/demo.flagd.json"
+    ]
     ports:
-      - "${FEATURE_FLAG_SERVICE_PORT}"                                  # Feature Flag Service UI
-      - "${FEATURE_FLAG_GRPC_SERVICE_PORT}"                             # Feature Flag Service gRPC API
-    environment:
-      - FEATURE_FLAG_SERVICE_PORT
-      - FEATURE_FLAG_GRPC_SERVICE_PORT
-      - OTEL_EXPORTER_OTLP_ENDPOINT
-      - OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=grpc
-      - OTEL_SERVICE_NAME=featureflagservice
-      - DATABASE_URL=ecto://ffs:ffs@ffspostgres:5432/ffs
-    healthcheck:
-      test: ["CMD", "curl", "-H", "baggage: synthetic_request=true", "-f", "http://localhost:${FEATURE_FLAG_SERVICE_PORT}"]
-    depends_on:
-      ffspostgres:
-        condition: service_healthy
-    logging: *logging
+      - 8013
+    volumes:
+      - ./src/flagd:/etc/flagd
+    logging:
+      *logging
 
   # Fraud Detection service
   frauddetectionservice:
@@ -333,8 +317,6 @@ services:
     environment:
       - FRONTEND_PORT
       - FRONTEND_HOST
-      - FEATURE_FLAG_SERVICE_PORT
-      - FEATURE_FLAG_SERVICE_HOST
       - LOCUST_WEB_HOST
       - LOCUST_WEB_PORT
       - GRAFANA_SERVICE_PORT
@@ -349,8 +331,6 @@ services:
     depends_on:
       frontend:
         condition: service_started
-      featureflagservice:
-        condition: service_started
       loadgenerator:
         condition: service_started
       jaeger:
@@ -436,7 +416,7 @@ services:
       - "${PRODUCT_CATALOG_SERVICE_PORT}"
     environment:
       - PRODUCT_CATALOG_SERVICE_PORT
-      - FEATURE_FLAG_GRPC_SERVICE_ADDR
+      - FLAGD_HOST
       - OTEL_EXPORTER_OTLP_ENDPOINT
       - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
       - OTEL_RESOURCE_ATTRIBUTES
@@ -493,16 +473,14 @@ services:
     environment:
       - RECOMMENDATION_SERVICE_PORT
       - PRODUCT_CATALOG_SERVICE_ADDR
-      - FEATURE_FLAG_GRPC_SERVICE_ADDR
+      - FLAGD_HOST
       - OTEL_PYTHON_LOG_CORRELATION=true
       - OTEL_EXPORTER_OTLP_ENDPOINT
       - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
       - OTEL_RESOURCE_ATTRIBUTES
       - OTEL_SERVICE_NAME=recommendationservice
       - PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
     depends_on:
-      featureflagservice:
-        condition: service_started
       productcatalogservice:
         condition: service_started
       otelcol:
@@ -539,33 +517,6 @@ services:
   # ******************
   # Dependent Services
   # ******************
-  # Postgres used by Feature Flag service
-  ffspostgres:
-    image: ${IMAGE_NAME}:${IMAGE_VERSION}-ffspostgres
-    container_name: ffs-postgres
-    build:
-      context: ./
-      dockerfile: ./src/ffspostgres/Dockerfile
-      cache_from:
-        - ${IMAGE_NAME}:${IMAGE_VERSION}-ffspostgres
-    deploy:
-      resources:
-        limits:
-          memory: 120M
-    restart: unless-stopped
-    environment:
-      - POSTGRES_USER=ffs
-      - POSTGRES_DB=ffs
-      - POSTGRES_PASSWORD=ffs
-    volumes:
-      - ./src/ffspostgres/update-scripts/99-ffs_update.sql:/docker-entrypoint-initdb.d/99-ffs_update.sql
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -d ffs -U ffs"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-    logging: *logging
-
   # Kafka used by Checkout, Accounting, and Fraud Detection services
   kafka:
     image: ${IMAGE_NAME}:${IMAGE_VERSION}-kafka

src/adservice/build.gradle

@@ -49,7 +49,9 @@ dependencies {
                 "io.opentelemetry:opentelemetry-api",
                 "io.opentelemetry:opentelemetry-sdk",
                 "io.opentelemetry.instrumentation:opentelemetry-instrumentation-annotations",
-                "org.apache.logging.log4j:log4j-core:2.21.1"
+                "org.apache.logging.log4j:log4j-core:2.21.1",
+                "dev.openfeature.contrib.providers:flagd:0.6.9",
+                'dev.openfeature:sdk:1.7.3'
 
         runtimeOnly "com.fasterxml.jackson.core:jackson-core:${jacksonVersion}",
                 "com.fasterxml.jackson.core:jackson-databind:${jacksonVersion}",

src/adservice/src/main/java/oteldemo/AdService.java

@@ -35,7 +35,11 @@
 import oteldemo.Demo.AdRequest;
 import oteldemo.Demo.AdResponse;
 import oteldemo.Demo.GetFlagResponse;
-import oteldemo.FeatureFlagServiceGrpc.FeatureFlagServiceBlockingStub;
+import dev.openfeature.contrib.providers.flagd.FlagdOptions;
+import dev.openfeature.contrib.providers.flagd.FlagdProvider;
+import dev.openfeature.sdk.Client;
+import dev.openfeature.sdk.OpenFeatureAPI;
+
 
 public final class AdService {
 
@@ -72,18 +76,18 @@ private void start() throws IOException {
                             "environment vars: AD_SERVICE_PORT must not be null")));
     healthMgr = new HealthStatusManager();
 
-    String featureFlagServiceAddr =
-        Optional.ofNullable(System.getenv("FEATURE_FLAG_GRPC_SERVICE_ADDR")).orElse("");
-    FeatureFlagServiceBlockingStub featureFlagServiceStub = null;
-    if (!featureFlagServiceAddr.isEmpty()) {
-      featureFlagServiceStub =
-          oteldemo.FeatureFlagServiceGrpc.newBlockingStub(
-              ManagedChannelBuilder.forTarget(featureFlagServiceAddr).usePlaintext().build());
-    }
+    // Create a flagd instance with OpenTelemetry
+    FlagdOptions options =
+        FlagdOptions.builder()
+            .withGlobalTelemetry(true)
+            .build();
 
+    FlagdProvider flagdProvider = new FlagdProvider(options);
+    // Set flagd as the OpenFeature Provider
+    OpenFeatureAPI.getInstance().setProvider(flagdProvider);
+
     server =
         ServerBuilder.forPort(port)
-            .addService(new AdServiceImpl(featureFlagServiceStub))
             .addService(healthMgr.getHealthService())
             .build()
             .start();
@@ -122,12 +126,6 @@ private static class AdServiceImpl extends oteldemo.AdServiceGrpc.AdServiceImplB
 
     private static final String ADSERVICE_FAIL_FEATURE_FLAG = "adServiceFailure";
 
-    private final FeatureFlagServiceBlockingStub featureFlagServiceStub;
-
-    private AdServiceImpl(FeatureFlagServiceBlockingStub featureFlagServiceStub) {
-      this.featureFlagServiceStub = featureFlagServiceStub;
-    }
-
     /**
      * Retrieves ads based on context provided in the request {@code AdRequest}.
      *
@@ -194,21 +192,14 @@ public void getAds(AdRequest req, StreamObserver<AdResponse> responseObserver) {
     }
 
     boolean checkAdFailure() {
-      if (featureFlagServiceStub == null) {
-        return false;
-      }
-
+      Client client = OpenFeatureAPI.getInstance().getClient();
+      Boolean boolValue = client.getBooleanValue("adServiceFailure", false);
       // Flip a coin and fail 1/10th of the time if feature flag is enabled
       if (random.nextInt(10) != 1) {
         return false;
       }
 
-      GetFlagResponse response =
-          featureFlagServiceStub.getFlag(
-              oteldemo.Demo.GetFlagRequest.newBuilder()
-                  .setName(ADSERVICE_FAIL_FEATURE_FLAG)
-                  .build());
-      return response.getFlag().getEnabled();
+      return boolValue;
     }
   }
 

src/cartservice/src/Program.cs

@@ -3,7 +3,6 @@
 using System;
 
 using cartservice.cartstore;
-using cartservice.featureflags;
 using cartservice.services;
 
 using Microsoft.AspNetCore.Builder;
@@ -17,6 +16,8 @@
 using OpenTelemetry.ResourceDetectors.Container;
 using OpenTelemetry.Resources;
 using OpenTelemetry.Trace;
+using OpenFeature;
+using OpenFeature.Contrib.Providers.Flagd;
 
 var builder = WebApplication.CreateBuilder(args);
 string redisAddress = builder.Configuration["REDIS_ADDR"];
@@ -37,13 +38,16 @@
     return store;
 });
 
-builder.Services.AddSingleton<FeatureFlagHelper>();
 builder.Services.AddSingleton(x => new CartService(x.GetRequiredService<ICartStore>(),
-    new RedisCartStore(x.GetRequiredService<ILogger<RedisCartStore>>(), "badhost:1234"),
-    x.GetRequiredService<FeatureFlagHelper>()));
+    new RedisCartStore(x.GetRequiredService<ILogger<RedisCartStore>>(), "badhost:1234"), x.GetRequiredService<IFeatureClient>()));
 
+builder.Services.AddSingleton<IFeatureClient>(x => {
+    var flagdProvider = new FlagdProvider();
+    Api.Instance.SetProviderAsync(flagdProvider).GetAwaiter().GetResult();
+    var client = Api.Instance.GetClient();
+    return client;
+});
 
-// see https://opentelemetry.io/docs/instrumentation/net/getting-started/
 
 Action<ResourceBuilder> appResourceBuilder =
     resource => resource

src/cartservice/src/cartservice.csproj

@@ -22,6 +22,8 @@
     <PackageReference Include="OpenTelemetry.Instrumentation.Runtime" Version="1.7.0" />
     <PackageReference Include="OpenTelemetry.ResourceDetectors.Container" Version="1.0.0-beta.6" />
     <PackageReference Include="StackExchange.Redis" Version="2.7.17" />
+    <PackageReference Include="OpenFeature.Contrib.Providers.Flagd" Version="0.1.8" />
+    <PackageReference Include="OpenFeature" Version="1.4.1" />
   </ItemGroup>
 
   <ItemGroup>

src/cartservice/src/services/CartService.cs

@@ -5,7 +5,7 @@
 using Grpc.Core;
 using OpenTelemetry.Trace;
 using cartservice.cartstore;
-using cartservice.featureflags;
+using OpenFeature;
 using Oteldemo;
 
 namespace cartservice.services;
@@ -15,9 +15,9 @@ public class CartService : Oteldemo.CartService.CartServiceBase
     private static readonly Empty Empty = new();
     private readonly ICartStore _badCartStore;
     private readonly ICartStore _cartStore;
-    private readonly FeatureFlagHelper _featureFlagHelper;
+    private readonly IFeatureClient _featureFlagHelper;
 
-    public CartService(ICartStore cartStore, ICartStore badCartStore, FeatureFlagHelper featureFlagService)
+    public CartService(ICartStore cartStore, ICartStore badCartStore, IFeatureClient featureFlagService)
     {
         _badCartStore = badCartStore;
         _cartStore = cartStore;
@@ -60,7 +60,7 @@ public override async Task<Empty> EmptyCart(EmptyCartRequest request, ServerCall
 
         try
         {
-            if (await _featureFlagHelper.GenerateCartError())
+            if (await _featureFlagHelper.GetBooleanValue("cartServiceFailure", false))
             {
                 await _badCartStore.EmptyCartAsync(request.UserId);
             }