src(templates)!: modify the nodejs event template to accept a cloudev…

…ent (#356)

* Simplify the nodejs events template

Pretty-printing the contents of the event and its envelope for each
request. This is handy when invoked as a Knative event sink as some
sources, e.g. Kafka, ignore the response body.

Co-authored-by: Lance Ball <lball@redhat.com>

* Expect the event parameter to be the entire CloudEvent

This will require a change to the faas-js-runtime, but at least the
template won't need to change when that's released

* Update nodejs guide to reflect 2nd arg's type is CloudEvent

* Templates now using faas-js-runtime 0.7.1

Co-authored-by: Lance Ball <lball@redhat.com>

docs/guides/nodejs.md

@@ -86,20 +86,27 @@ If you prefer another, that's no problem. Just remove the `tape` dependency from
 
 ## Function reference
 
-Boson Node.js functions have very few restrictions. You can add any required dependencies
-in `package.json`, and you may include additional local JavaScript files. The only real
-requirements are that your project contain an `index.js` file which exports a single function.
-In this section, we will look in a little more detail at how Boson functions are invoked,
-and what APIs are available to you as a developer.
+Boson Node.js functions have very few restrictions. You can add any
+required dependencies in `package.json`, and you may include
+additional local JavaScript files. The only real requirements are that
+your project contain an `index.js` file which exports a single
+function.  In this section, we will look in a little more detail at
+how Boson functions are invoked, and what APIs are available to you as
+a developer.
 
 ### Invocation parameters
 
-When using the `func` CLI to create a function project, you may choose to generate a project
-that responds to a `CloudEvent` or simple HTTP. `CloudEvents` in Knative are transported over
-HTTP as a `POST` request, so in many ways, the two types of functions are very much the same.
-They each will listen and respond to incoming HTTP events.
+When using the `func` CLI to create a function project, you may choose
+to generate a project that responds to a `CloudEvent` or simple
+HTTP. `CloudEvents` in Knative are transported over HTTP as a `POST`
+request, so in many ways, the two types of functions are very much the
+same.  They each will listen and respond to incoming HTTP events.
 
-When an incoming request is received, your function will be invoked with a `Context` object as the first parameter. If the incoming request is a `CloudEvent`, any data associated with the `CloudEvent` is extracted from the event and provided as a second parameter. For example, a `CloudEvent` is received which contains a JSON string such as this in its data property, 
+When an incoming request is received, your function will be invoked
+with a `Context` object as the first parameter. If the incoming
+request is a `CloudEvent`, it will be provided as the second
+parameter. For example, a `CloudEvent` is received which contains a
+JSON string such as this in its data property,
 
 ```json
 { 
@@ -108,12 +115,12 @@ When an incoming request is received, your function will be invoked with a `Cont
 }
 ```
 
-When invoked, the second parameter to the function, after the `Context` object, will be
-a JavaScript object having `customerId` and `productId` properties. The function
-signature might look like this, with the `data` parameter having these properties.
+So to log that string from your function, you might do this:
 
 ```js
-function processPurchase(context, data)
+function handle(context, event) {
+  console.log(JSON.stringify(event.data, null, 2));
+}
 ```
 ### Return Values
 Functions may return any valid JavaScript type, or nothing at all. When a
@@ -126,7 +133,10 @@ the returned values are extracted and sent with the response.
 
 #### Example
 ```js
-function processCustomer(context, customer) {
+function handle(context, event) {
+  return processCustomer(event.data)
+}
+function processCustomer(customer) {
   // process customer and return a new CloudEvent
   return new CloudEvent({
     source: 'customer.processor',
@@ -142,7 +152,7 @@ extracted and sent with the response to the caller.
 
 #### Example
 ```js
-function processCustomer(context, customer) {
+function processCustomer(customer) {
   // process customer and return custom headers
   // the response will be '204 No content'
   return { headers: { customerid: customer.id } }; 
@@ -155,7 +165,7 @@ Developers may set the response code returned to the caller by adding a
 
 #### Example
 ```js
-function processCustomer(context, customer) {
+function processCustomer(customer) {
   // process customer
   if (customer.restricted) {
     return { statusCode: 451 }
@@ -167,7 +177,7 @@ This also works with `Error` objects thrown from the function.
 
 #### Example
 ```js
-function processCustomer(context, customer) {
+function processCustomer(customer) {
   // process customer
   if (customer.restricted) {
     const err = new Error(‘Unavailable for legal reasons’);
@@ -193,7 +203,7 @@ The log adheres to the Pino logging API (https://getpino.io/#/docs/api).
 
 #### Example
 ```js
-Function myFunction(context) {
+Function handle(context) {
   context.log.info(“Processing customer”);
 }
 ```
@@ -216,7 +226,7 @@ attributes are also found on the context object itself.
 
 #### Example
 ```js
-Function myFunction(context) {
+Function handle(context) {
   // Log the 'name' query parameter
   context.log.info(context.query.name);
   // Query parameters also are attached to the context
@@ -242,7 +252,7 @@ be parsed so that the attributes are directly available.
 
 #### Example
 ```js
-Function myFunction(context) {
+Function handle(context) {
   // log the incoming request body's 'hello' parameter
   context.log.info(context.body.hello);
 }
@@ -264,7 +274,7 @@ Returns the HTTP request headers as an object.
 
 #### Example
 ```js
-Function myFunction(context) {
+Function handle(context) {
   context.log.info(context.headers[custom-header]);
 }
 ```
@@ -309,10 +319,10 @@ A function which accepts a data value and returns a CloudEvent.
 #### Example
 ```js
 // Expects to receive a CloudEvent with customer data
-function processCustomer(context, customer) {
+function handle(context, event) {
   // process the customer
-  const processed = processCustomer(customer);
-  return context.cloudEventResponse(customer);
+  const processed = processCustomer(event.data);
+  return context.cloudEventResponse(processed);
 }
 ```
 

templates/node/events/README.md

@@ -1,13 +1,8 @@
 # Node.js Cloud Events Function
 
-Welcome to your new Node.js function project! The boilerplate function code can
-be found in [`index.js`](./index.js). This function is meant to respond
-exclusively to [Cloud Events](https://cloudevents.io/), but you can remove the
-check for this in the function and it will respond just fine to plain vanilla
-incoming HTTP requests. Additionally, this example function is written
-asynchronously, returning a `Promise`. If your function does not perform any
-asynchronous execution, you can safely remove the `async` keyword from the
-function, and return raw values instead of a `Promise`.
+Welcome to your new Node.js function project! The boilerplate function
+code can be found in [`index.js`](./index.js). This function is meant
+to respond to [Cloud Events](https://cloudevents.io/).
 
 ## Local execution
 

templates/node/events/index.js

@@ -2,8 +2,10 @@
 const { CloudEvent, HTTP } = require('cloudevents');
 
 /**
- * An example function that responds to incoming CloudEvents over HTTP. For example,
- * from the Knative event Broker. Try invoking with a request such as this.
+ * A function that responds to incoming CloudEvents over HTTP from,
+ * for example, a Knative event Source, Channel or Broker.
+ *
+ * If running via 'npm run local', it can be invoked like so:
  *
  * curl -X POST -d '{"name": "Tiger", "customerId": "0123456789"}' \
  *  -H'Content-type: application/json' \
@@ -13,37 +15,22 @@ const { CloudEvent, HTTP } = require('cloudevents');
  *  -H'Ce-specversion: 1.0' \
  *  http://localhost:8080
  *
- * The event data is extracted from the incoming event and provided as the first
- * parameter to the function. The CloudEvent object itself may be accessed via the
- * context parameter, For example:
- *
- * const incomingEvent = context.cloudevent;
- *
  * @param {Context} context the invocation context
- * @param {Object} user the CloudEvent data. If the data content type is application/json
- * this will be converted to an Object via JSON.parse()
+ * @param {Object} event the CloudEvent 
  */
-function verifyUser(context, user) {
-  if (!context.cloudevent) {
-    return {
-      message: 'No cloud event received'
-    };
-  }
+function handle(context, event) {
 
-  context.log.info('Processing user', user);
-  context.log.info(`CloudEvent received: ${context.cloudevent.toString()}`);
+  context.log.info("context");
+  console.log(JSON.stringify(context, null, 2));
+
+  context.log.info("event");
+  console.log(JSON.stringify(event, null, 2));
 
-  user = verify(user);
   return HTTP.binary(new CloudEvent({
-    source: 'function.verifyUser',
-    type: 'user:verified',
-    data: user
+    source: 'event.handler',
+    type: 'echo',
+    data: event
   }));
 };
 
-function verify(user) {
-  // do something with the user
-  return user;
-}
-
-module.exports = verifyUser;
+module.exports = handle;

templates/node/events/package.json

@@ -13,7 +13,7 @@
     "debug": "nodemon --inspect ./node_modules/faas-js-runtime/bin/cli.js ./index.js"
   },
   "devDependencies": {
-    "faas-js-runtime": "0.6.0",
+    "faas-js-runtime": "0.7.1",
     "nodemon": "^2.0.4",
     "supertest": "^4.0.2",
     "tape": "^4.13.0"