[frontend + adservice] Pass Session ID through baggage (#1502)

* pass session ID as baggage to adservice

* address review comments

Author: austinlparker

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

@@ -12,13 +12,16 @@
 import io.grpc.protobuf.services.*;
 import io.grpc.stub.StreamObserver;
 import io.opentelemetry.api.GlobalOpenTelemetry;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.baggage.Baggage;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.metrics.LongCounter;
 import io.opentelemetry.api.metrics.Meter;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.StatusCode;
 import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Context;
 import io.opentelemetry.context.Scope;
 import io.opentelemetry.instrumentation.annotations.SpanAttribute;
 import io.opentelemetry.instrumentation.annotations.WithSpan;
@@ -132,7 +135,8 @@ private static class AdServiceImpl extends oteldemo.AdServiceGrpc.AdServiceImplB
     private static final String ADSERVICE_FAILURE = "adServiceFailure";
     private static final String ADSERVICE_MANUAL_GC_FEATURE_FLAG = "adServiceManualGc";
     private static final String ADSERVICE_HIGH_CPU_FEATURE_FLAG = "adServiceHighCpu";
-
+    Client ffClient = OpenFeatureAPI.getInstance().getClient();
+    
     private AdServiceImpl() {}
 
     /**
@@ -155,6 +159,15 @@ public void getAds(AdRequest req, StreamObserver<AdResponse> responseObserver) {
         AdRequestType adRequestType;
         AdResponseType adResponseType;
 
+        Baggage baggage = Baggage.fromContextOrNull(Context.current());
+        if (baggage != null) {
+          final String sessionId = baggage.getEntryValue("session.id");
+          span.setAttribute("session.id", sessionId);
+          ffClient.setEvaluationContext(new MutableContext().add("session", sessionId));
+        } else {
+          logger.info("no baggage found in context");
+        }
+
         span.setAttribute("app.ads.contextKeys", req.getContextKeysList().toString());
         span.setAttribute("app.ads.contextKeys.count", req.getContextKeysCount());
         if (req.getContextKeysCount() > 0) {
@@ -214,11 +227,7 @@ public void getAds(AdRequest req, StreamObserver<AdResponse> responseObserver) {
      * @return {@code true} if the feature flag is enabled, {@code false} otherwise or in case of errors.
      */
     boolean getFeatureFlagEnabled(String ff) {
-      Client client = OpenFeatureAPI.getInstance().getClient();
-      // TODO: Plumb the actual session ID from the frontend via baggage?
-      UUID uuid = UUID.randomUUID();
-      client.setEvaluationContext(new MutableContext().add("session", uuid.toString()));
-      Boolean boolValue = client.getBooleanValue(ff, false);
+      Boolean boolValue = ffClient.getBooleanValue(ff, false);
       return boolValue;
     }
   }

src/frontend/gateways/Api.gateway.ts

@@ -4,7 +4,9 @@
 import { Ad, Address, Cart, CartItem, Money, PlaceOrderRequest, Product } from '../protos/demo';
 import { IProductCart, IProductCartItem, IProductCheckout } from '../types/Cart';
 import request from '../utils/Request';
+import { AttributeNames } from '../utils/enums/AttributeNames';
 import SessionGateway from './Session.gateway';
+import { context, propagation } from "@opentelemetry/api";
 
 const { userId } = SessionGateway.getSession();
 
@@ -82,11 +84,18 @@ const ApiGateway = () => ({
     });
   },
   listAds(contextKeys: string[]) {
-    return request<Ad[]>({
-      url: `${basePath}/data`,
-      queryParams: {
-        contextKeys,
-      },
+    // TODO: Figure out a better way to do this so session ID gets propagated to
+    // all endpoints
+    const baggage = propagation.getActiveBaggage() || propagation.createBaggage();
+    const newBaggage = baggage.setEntry(AttributeNames.SESSION_ID, { value: userId });
+    const newContext = propagation.setBaggage(context.active(), newBaggage);
+    context.with(newContext, () => {
+      return request<Ad[]>({
+        url: `${basePath}/data`,
+        queryParams: {
+          contextKeys,
+        },
+      });
     });
   },
 });

src/frontend/providers/Ad.provider.tsx

@@ -29,9 +29,9 @@ const AdProvider = ({ children, productIds, contextKeys }: IProps) => {
   const { selectedCurrency } = useCurrency();
   const { data: adList = [] } = useQuery(
     ['ads', contextKeys],
-    () => {
+    async () => {
       if (contextKeys.length === 0) {
-        return Promise.resolve([]);
+        return [];
       } else {
         return ApiGateway.listAds(contextKeys);
       }

src/frontend/utils/enums/AttributeNames.ts

@@ -2,5 +2,5 @@
 // SPDX-License-Identifier: Apache-2.0
 
 export enum AttributeNames {
-    SESSION_ID = 'app.session.id'
+    SESSION_ID = 'session.id'
 }