[GitHub] rabbah commented on a change in pull request #2958: initial support for nodejs8

[GitBox <gi...@apache.org>]

rabbah commented on a change in pull request #2958: initial support for nodejs8
URL: https://github.com/apache/incubator-openwhisk/pull/2958#discussion_r151793650
 
 

 ##########
 File path: docs/actions.md
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 @@ -493,6 +494,90 @@ To create an OpenWhisk action from this package:
 
 Finally, note that while most `npm` packages install JavaScript sources on `npm install`, some also install and compile binary artifacts. The archive file upload currently does not support binary dependencies but rather only JavaScript dependencies. Action invocations may fail if the archive includes binary dependencies.
 
+### Package an action as a single bundle
+
+It is convenient to only include the minimal code into a single `.js` file that includes dependencies. This approach allows for faster deployments, and in some circumstances where packaging the action as a zip might be too large because it includes unnecessary files.
+
+You can use a JavaScript module bundler such as [webpack](https://webpack.js.org/concepts/). When webpack processes your code, it recursively builds a dependency graph that includes every module that your action needs.
+
+Here is a quick example using webpack:
+
+Taking the previous example `package.json` add `webpack` as a development depency and add some npm script commands.
+```json
+{
+  "name": "my-action",
+  "main": "dist/bundle.js",
+  "scripts": {
+    "build": "webpack --config webpack.config.js",
+    "deploy": "wsk action update my-action dist/bundle.js --kind nodejs:8"
+  },
+  "dependencies": {
+    "left-pad": "1.1.3"
+  },
+  "devDependencies": {
+    "webpack": "^3.8.1"
+  }
+}
+```
+
+Create the webpack configuration file `webpack.config.js`.
+```javascript
+var path = require('path');
+module.exports = {
+  entry: './index.js',
+  output: {
+    path: path.resolve(__dirname, 'dist'),
+    filename: 'bundle.js'
+  },
+  target: 'node'
+};
+```
+
+Set the variable `global.main` to the main function of the action.
+From the previous example:
+```javascript
+function myAction(args) {
+    const leftPad = require("left-pad")
+    const lines = args.lines || [];
+    return { padded: lines.map(l => leftPad(l, 30, ".")) }
+}
+global.main = myAction;
+```
+
+If your function name is `main`, use this syntax instead:
+```javascript
+global.main = main;
+```
+
+To build and deploy an OpenWhisk Action using `npm` and `webpack`:
+
+1. First, install dependencies locally:
+
+  ```
+  npm install
+  ```
+
+2. Build the webpack bundle:
+
+  ```
+  npm run build
+  ```
+
+  The file `dist/bundle.js` is created, and is used to deploy as the Action source code.
+
+3. Create the Action using the `npm` script or the CLI.
+  Using `npm` script:
+  ```
+  npm run deploy
+  ```
+  {: pre}
+  Using the CLI:
+  ```
+  bx wsk action update my-action dist/bundle.js
 
 Review comment:
   what's bx?

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