Sample App: Event Driven Architecture I (#5928)

* Add the node.js server

* Setting up the infrastructure

* Update the port of the node application

* Add the sinkBinding

* Adding the reply feedback loop

* Adding the response into the nodejs server

* Change the naming convention

* Update the index.js to remove the uncessary comments

.gitignore

@@ -36,3 +36,4 @@ maven-wrapper.jar
 
 # Ignore Python virtual environments
 .venv
+/code-samples/eventing/bookstore-sample-app/db/bookstore-eda/node_modules/*

code-samples/eventing/bookstore-sample-app/db/bookstore-eda/Dockerfile

@@ -0,0 +1,20 @@
+# Use a base image with Node.js
+FROM node:18
+
+# Set the working directory in the container
+WORKDIR /app
+
+# Copy package.json and package-lock.json to the container
+COPY package*.json ./
+
+# Install dependencies
+RUN npm install
+
+# Copy the application code to the container
+COPY . .
+
+# Expose the port on which the application will run
+EXPOSE 8000
+
+# Specify the command to start the application
+CMD [ "node", "index.js" ]

code-samples/eventing/bookstore-sample-app/db/bookstore-eda/broker.yaml

@@ -0,0 +1,4 @@
+apiVersion: eventing.knative.dev/v1
+kind: Broker
+metadata:
+  name: broker

code-samples/eventing/bookstore-sample-app/db/bookstore-eda/deployment.yaml

@@ -0,0 +1,21 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: eda
+  labels:
+    app: eda
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: eda
+  template:
+    metadata:
+      labels:
+        app: eda
+    spec:
+      containers:
+      - name: eda
+        image: quay.io/rh-ee-leoli/eda:latest
+        ports:
+        - containerPort: 8000

code-samples/eventing/bookstore-sample-app/db/bookstore-eda/event-display.yaml

@@ -0,0 +1,9 @@
+apiVersion: serving.knative.dev/v1
+kind: Service
+metadata:
+  name: event-display
+spec:
+  template:
+    spec:
+      containers:
+        - image: gcr.io/knative-releases/knative.dev/eventing-contrib/cmd/event_display

code-samples/eventing/bookstore-sample-app/db/bookstore-eda/index.js

@@ -0,0 +1,53 @@
+const express = require('express');
+const { HTTP, CloudEvent } = require('cloudevents');
+
+const app = express();
+const port = 8000;
+
+
+// Middleware to parse JSON bodies
+app.use(express.json());
+
+
+app.post('/add', async (req, res) => {
+    try {
+        const receivedEvent = HTTP.toEvent({ headers: req.headers, body: req.body });
+        const brokerURI = process.env.K_SINK;
+
+        if (receivedEvent.type === 'new-review-comment') {
+            // Forward the event to the broker with the necessary CloudEvent headers
+            const response = await fetch(brokerURI, {
+                method: 'POST',
+                headers: {
+                    'Content-Type': 'application/json',
+                    'ce-specversion': '1.0',
+                    'ce-type': 'sentiment-analysis-request',
+                    'ce-source': 'bookstore-eda',
+                    'ce-id': receivedEvent.id,
+                },
+                body: JSON.stringify(receivedEvent.data),
+            });
+
+            if (!response.ok) { // If the response status code is not 2xx, consider it a failure
+                console.error('Failed to forward event:', receivedEvent);
+                return res.status(500).json({ error: 'Failed to forward event' });
+            }
+
+            // If forwarding was successful, acknowledge the receipt of the event
+            console.log('Event forwarded successfully:', receivedEvent);
+            return res.status(200).json({ success: true, message: 'Event forwarded successfully' });
+        } else {
+            // Handle unexpected event types
+            console.warn('Unexpected event type:', receivedEvent.type);
+            return res.status(400).json({ error: 'Unexpected event type' });
+        }
+    } catch (error) {
+        console.error('Error processing request:', error);
+        return res.status(500).json({ error: 'Internal server error' });
+    }
+});
+
+// Start the server
+app.listen(port, () => {
+    console.log(`Server listening at http://localhost:${port}`);
+});