load product catalog periodically (open-telemetry#1919)

* load product catalog periodically

* load product catalog periodically

* revert changed product name

* fix indent

* add products.json mount

* remove COPY products.json

---------

Co-authored-by: Juliano Costa <julianocosta89@outlook.com>

Author: puckpuck

.env

@@ -107,6 +107,7 @@ PAYMENT_ADDR=payment:${PAYMENT_PORT}
 PAYMENT_DOCKERFILE=./src/payment/Dockerfile
 
 # Product Catalog Service
+PRODUCT_CATALOG_RELOAD_INTERVAL=10
 PRODUCT_CATALOG_PORT=3550
 PRODUCT_CATALOG_ADDR=product-catalog:${PRODUCT_CATALOG_PORT}
 PRODUCT_CATALOG_DOCKERFILE=./src/product-catalog/Dockerfile

CHANGELOG.md

@@ -72,6 +72,8 @@ the release.
   ([#1897](https://github.com/open-telemetry/opentelemetry-demo/pull/1897))
 * [frontend-proxy] rename frontendproxy to frontend-proxy
   ([#1910](https://github.com/open-telemetry/opentelemetry-demo/pull/1910))
+* [product-catalog] load product list on a periodic timer
+  ([#1919](https://github.com/open-telemetry/opentelemetry-demo/pull/1919))
 * [flagd-ui] fixed eslint ignore comment with useCallback
   ([#1923](https://github.com/open-telemetry/opentelemetry-demo/pull/1923))
 * [chore] Add memory for frontend-proxy, kafka, grafana, opensearch

Makefile

@@ -171,7 +171,7 @@ start:
 	@echo "Go to http://localhost:8080/jaeger/ui for the Jaeger UI."
 	@echo "Go to http://localhost:8080/grafana/ for the Grafana UI."
 	@echo "Go to http://localhost:8080/loadgen/ for the Load Generator UI."
-	@echo "Go to http://localhost:8080/feature/ to to change feature flags."
+	@echo "Go to http://localhost:8080/feature/ to change feature flags."
 
 .PHONY: start-minimal
 start-minimal:

docker-compose.minimal.yml

@@ -399,10 +399,13 @@ services:
     environment:
       - FLAGD_HOST
       - PRODUCT_CATALOG_PORT
+      - PRODUCT_CATALOG_RELOAD_INTERVAL
       - OTEL_EXPORTER_OTLP_ENDPOINT
       - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
       - OTEL_RESOURCE_ATTRIBUTES
       - OTEL_SERVICE_NAME=product-catalog
+    volumes:
+      - ./src/product-catalog/products:/usr/src/app/products
     depends_on:
       otel-collector:
         condition: service_started

docker-compose.yml

@@ -477,12 +477,15 @@ services:
       - "${PRODUCT_CATALOG_PORT}"
     environment:
       - PRODUCT_CATALOG_PORT
+      - PRODUCT_CATALOG_RELOAD_INTERVAL
       - FLAGD_HOST
       - FLAGD_PORT
       - OTEL_EXPORTER_OTLP_ENDPOINT
       - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
       - OTEL_RESOURCE_ATTRIBUTES
       - OTEL_SERVICE_NAME=product-catalog
+    volumes:
+      - ./src/product-catalog/products:/usr/src/app/products
     depends_on:
       otel-collector:
         condition: service_started

src/product-catalog/Dockerfile

@@ -20,7 +20,6 @@ FROM alpine AS release
 
 WORKDIR /usr/src/app/
 
-COPY ./src/product-catalog/products/ ./products/
 COPY --from=builder /go/bin/product-catalog/ ./
 
 EXPOSE ${PRODUCT_CATALOG_PORT}

src/product-catalog/main.go

@@ -13,6 +13,7 @@ import (
 	"net"
 	"os"
 	"os/signal"
+	"strconv"
 	"strings"
 	"sync"
 	"syscall"
@@ -53,14 +54,12 @@ var (
 	initResourcesOnce sync.Once
 )
 
+const DEFAULT_RELOAD_INTERVAL = 10
+
 func init() {
 	log = logrus.New()
-	var err error
-	catalog, err = readProductFiles()
-	if err != nil {
-		log.Fatalf("Reading Product Files: %v", err)
-		os.Exit(1)
-	}
+
+	loadProductCatalog()
 }
 
 func initResource() *sdkresource.Resource {
@@ -178,6 +177,43 @@ type productCatalog struct {
 	pb.UnimplementedProductCatalogServiceServer
 }
 
+func loadProductCatalog() {
+	log.Info("Loading Product Catalog...")
+	var err error
+	catalog, err = readProductFiles()
+	if err != nil {
+		log.Fatalf("Error reading product files: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Default reload interval is 10 seconds
+	interval := DEFAULT_RELOAD_INTERVAL
+	si := os.Getenv("PRODUCT_CATALOG_RELOAD_INTERVAL")
+	if si != "" {
+		interval, _ = strconv.Atoi(si)
+		if interval <= 0 {
+			interval = DEFAULT_RELOAD_INTERVAL
+		}
+	}
+	log.Infof("Product Catalog reload interval: %d", interval)
+
+	ticker := time.NewTicker(time.Duration(interval) * time.Second)
+
+	go func() {
+		for {
+			select {
+			case <-ticker.C:
+				log.Info("Reloading Product Catalog...")
+				catalog, err = readProductFiles()
+				if err != nil {
+					log.Errorf("Error reading product files: %v", err)
+					continue
+				}
+			}
+		}
+	}()
+}
+
 func readProductFiles() ([]*pb.Product, error) {
 
 	// find all .json files in the products directory