Update Node.js code samples w/ latest CloudEvents (#4865)

This commit updates two of the examples in this repository that use the
Node.js CloudEvents module. A newer version of the module has been released
and the examples have been updated to use it. The newer version allows us
to eliminate a dependency on axios, and simplify the example code.

Signed-off-by: Lance Ball <lball@redhat.com>

code-samples/eventing/writing-event-source-easy-way/README.md

@@ -25,8 +25,7 @@ The following example event source emits an event to the sink every second:
 
 ```javascript
 // File - index.js
-const got = require('got');
-const { CloudEvent, Emitter, emitterFor } = require('cloudevents');
+const { CloudEvent, Emitter, emitterFor, httpTransport } = require('cloudevents');
 
 const K_SINK = process.env['K_SINK'];
 K_SINK || logExit('Error: K_SINK Environment variable is not defined');
@@ -47,17 +46,7 @@ setInterval(() => {
 }, 1000);
 
 // Create a function that can post an event
-const emit = emitterFor(event => {
-  got.post(K_SINK, event)
-    .then(response => {
-      console.log('Event posted successfully');
-      console.log(response.data);
-    })
-    .catch(err => {
-      console.log('Error during event post');
-      console.error(err);
-    });
-  });
+const emit = emitterFor(httpTransport(K_SINK));
 
 // Send the CloudEvent any time a Node.js 'cloudevent' event is emitted
 Emitter.on('cloudevent', emit);
@@ -76,7 +65,7 @@ function registerGracefulExit() {
 
 function logExit(message = 'Exiting...') {
   // Handle graceful exit
-  console.log(message);
+  process.stdout.write(`${message}\n`);
   process.exit();
 }
 ```

code-samples/eventing/writing-event-source-easy-way/index.js

@@ -1,5 +1,4 @@
-const got = require('got');
-const { CloudEvent, Emitter, emitterFor } = require('cloudevents');
+const { CloudEvent, Emitter, emitterFor, httpTransport } = require('cloudevents');
 
 const K_SINK = process.env['K_SINK'];
 K_SINK || logExit('Error: K_SINK Environment variable is not defined');
@@ -20,17 +19,7 @@ setInterval(() => {
 }, 1000);
 
 // Create a function that can post an event
-const emit = emitterFor(event => {
-  got.post(K_SINK, event)
-    .then(response => {
-      console.log('Event posted successfully');
-      console.log(response.data);
-    })
-    .catch(err => {
-      console.log('Error during event post');
-      console.error(err);
-    });
-  });
+const emit = emitterFor(httpTransport(K_SINK));
 
 // Send the CloudEvent any time a Node.js 'cloudevent' event is emitted
 Emitter.on('cloudevent', emit);
@@ -49,6 +38,6 @@ function registerGracefulExit() {
 
 function logExit(message = 'Exiting...') {
   // Handle graceful exit
-  console.log(message);
+  process.stdout.write(`${message}\n`);
   process.exit();
 }

code-samples/eventing/writing-event-source-easy-way/package.json

@@ -10,7 +10,6 @@
   "author": "",
   "license": "ISC",
   "dependencies": {
-    "cloudevents": "^4.0.3",
-    "got": "^11.8.2"
+    "cloudevents": "^6.0.1"
   }
 }

code-samples/serving/cloudevents/cloudevents-nodejs/index.js

@@ -15,11 +15,11 @@ limitations under the License.
 */
 
 const express = require('express')
-const { CloudEvent, HTTP } = require('cloudevents')
+const { CloudEvent, HTTP, emitterFor, httpTransport } = require('cloudevents')
 const PORT = process.env.PORT || 8080
 const target = process.env.K_SINK
 const app = express()
-const axios = require('axios').default;
+const emit = target ? emitterFor(httpTransport(target)) : null
 
 const main = () => {
   app.listen(PORT, function () {
@@ -42,23 +42,15 @@ const receiveAndSend = (cloudEvent, res) => {
     source: 'https://github.com/knative/docs/code-samples/serving/cloudevents/cloudevents-nodejs',
     data
   })
-  const message = HTTP.binary(ce); // Or HTTP.structured(ce))
 
   // Reply back to dispatcher/client as soon as possible
   res.status(202).end()
 
-  axios({
-    method: 'post',
-    url: target,
-    data: message.body,
-    headers: message.headers,
-  })
-  .then((responseSink) => {
+  emit(ce).then((responseSink) => {
     console.log(`Sent event: ${JSON.stringify(ce, null, 2)}`)
     console.log(`K_SINK responded: ${JSON.stringify({ status: responseSink.status, headers: responseSink.headers, data: responseSink.data }, null, 2)}`)
   })
   .catch(console.error)
-
 }
 
 // receiveAndReply responds with new event
@@ -71,7 +63,7 @@ const receiveAndReply = (cloudEvent, res) => {
   })
 
   console.log(`Reply event: ${JSON.stringify(ce, null, 2)}`)
-  const message = HTTP.binary(ce);
+  const message = HTTP.binary(ce)
   res.set(message.headers)
   res.status(200).send(message.body)
 }
@@ -90,7 +82,7 @@ app.use((req, res, next) => {
 
 app.post('/', function (req, res) {
   try {
-    const event = HTTP.toEvent({headers: req.headers, body: req.body})
+    const event = HTTP.toEvent({ headers: req.headers, body: req.body })
     console.log(`Accepted event: ${JSON.stringify(event, null, 2)}`)
     target ? receiveAndSend(event, res) : receiveAndReply(event, res)
   } catch (err) {

code-samples/serving/cloudevents/cloudevents-nodejs/package.json

@@ -13,9 +13,8 @@
   "author": "",
   "license": "Apache-2.0",
   "dependencies": {
-    "axios": "^0.21.2",
-    "cloudevents": "^4.0.3",
-    "express": "^4.17.1",
+    "cloudevents": "^6.0.1",
+    "express": "^4.17.3",
     "nodemon": "^2.0.4"
   },
   "devDependencies": {