Move the Online Boutique application into its own repository.

We will use the newly created repository to run continuous deployment
of the application to GKE.

.github/workflows/go.yml

@@ -0,0 +1,46 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Build and Test
+
+on:
+  push:
+    branches:
+    - 'main'
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+    steps:
+    - name: Check out repository
+      uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: '1.20'
+        cache: true
+
+    - name: build
+      run: go build ./...
+    - name: vet
+      run: go vet ./...
+    - name: test
+      run: go test ./...
+    - name: testrace
+      run: go test -race ./...
+

README.md

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+# Online Boutique
+
+This directory contains the port of the Google Cloud's [`Online
+Boutique`][boutique] demo application to Service Weaver.
+
+```mermaid
+%%{init: {"flowchart": {"defaultRenderer": "elk"}} }%%
+graph TD
+    %% Nodes.
+    github.com/ServiceWeaver/weaver/Main(weaver.Main)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/adservice/T(adservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/cartservice/T(cartservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/cartservice/cartCache(cartservice.cartCache)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T(checkoutservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/currencyservice/T(currencyservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/emailservice/T(emailservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/paymentservice/T(paymentservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/productcatalogservice/T(productcatalogservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/recommendationservice/T(recommendationservice.T)
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/shippingservice/T(shippingservice.T)
+
+    %% Edges.
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/adservice/T
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/cartservice/T
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/currencyservice/T
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/productcatalogservice/T
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/recommendationservice/T
+    github.com/ServiceWeaver/weaver/Main --> github.com/ServiceWeaver/weaver/examples/onlineboutique/shippingservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/cartservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/cartservice/cartCache
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/cartservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/currencyservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/emailservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/paymentservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/productcatalogservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/checkoutservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/shippingservice/T
+    github.com/ServiceWeaver/weaver/examples/onlineboutique/recommendationservice/T --> github.com/ServiceWeaver/weaver/examples/onlineboutique/productcatalogservice/T
+```
+
+Here are the changes made to the original application:
+
+* All of the services that weren't written in `Go` have been ported to `Go`.
+* All of the networking calls have been replaced with the corresponding
+  Service Weaver calls.
+* All of the logging/tracing/monitoring calls have been replaced with the
+  corresponding Service Weaver calls.
+* The code is organized as a single Go module.
+
+[boutique]: https://github.com/GoogleCloudPlatform/microservices-demo

adservice/service.go

@@ -0,0 +1,120 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adservice
+
+import (
+	"context"
+	"math/rand"
+	"strings"
+
+	"golang.org/x/exp/maps"
+
+	"github.com/ServiceWeaver/weaver"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+const (
+	maxAdsToServe = 2
+)
+
+// Ad represents an advertisement.
+type Ad struct {
+	weaver.AutoMarshal
+	RedirectURL string // URL to redirect to when an ad is clicked.
+	Text        string // Short advertisement text to display.
+}
+
+type T interface {
+	GetAds(ctx context.Context, keywords []string) ([]Ad, error)
+}
+
+type impl struct {
+	weaver.Implements[T]
+	ads map[string]Ad
+}
+
+func (s *impl) Init(context.Context) error {
+	s.Logger().Info("Ad Service started")
+	s.ads = createAdsMap()
+	return nil
+}
+
+// GetAds returns a list of ads that best match the given context keywords.
+func (s *impl) GetAds(ctx context.Context, keywords []string) ([]Ad, error) {
+	s.Logger().Info("received ad request", "keywords", keywords)
+	span := trace.SpanFromContext(ctx)
+	var allAds []Ad
+	if len(keywords) > 0 {
+		span.AddEvent("Constructing Ads using context", trace.WithAttributes(
+			attribute.String("Context Keys", strings.Join(keywords, ",")),
+			attribute.Int("Context Keys length", len(keywords)),
+		))
+		for _, kw := range keywords {
+			allAds = append(allAds, s.getAdsByCategory(kw)...)
+		}
+		if allAds == nil {
+			// Serve random ads.
+			span.AddEvent("No Ads found based on context. Constructing random Ads.")
+			allAds = s.getRandomAds()
+		}
+	} else {
+		span.AddEvent("No Context provided. Constructing random Ads.")
+		allAds = s.getRandomAds()
+	}
+	return allAds, nil
+}
+
+func (s *impl) getAdsByCategory(category string) []Ad {
+	return []Ad{s.ads[category]}
+}
+
+func (s *impl) getRandomAds() []Ad {
+	ads := make([]Ad, maxAdsToServe)
+	vals := maps.Values(s.ads)
+	for i := 0; i < maxAdsToServe; i++ {
+		ads[i] = vals[rand.Intn(len(vals))]
+	}
+	return ads
+}
+
+func createAdsMap() map[string]Ad {
+	return map[string]Ad{
+		"hair": {
+			RedirectURL: "/product/2ZYFJ3GM2N",
+			Text:        "Hairdryer for sale. 50% off.",
+		},
+		"clothing": {
+			RedirectURL: "/product/66VCHSJNUP",
+			Text:        "Tank top for sale. 20% off.",
+		},
+		"accessories": {
+			RedirectURL: "/product/1YMWWN1N4O",
+			Text:        "Watch for sale. Buy one, get second kit for free",
+		},
+		"footwear": {
+			RedirectURL: "/product/L9ECAV7KIM",
+			Text:        "Loafers for sale. Buy one, get second one for free",
+		},
+		"decor": {
+			RedirectURL: "/product/0PUK6V6EV0",
+			Text:        "Candle holder for sale. 30% off.",
+		},
+		"kitchen": {
+			RedirectURL: "/product/9SIQT8TOJO",
+			Text:        "Bamboo glass jar for sale. 10% off.",
+		},
+	}
+}