Bundling OpenWhisk Actions with Webpack

This is an example OpenWhisk action that is meant to be bundled with Webpack. When creating an action on OpenWhisk with JavaScript, it requires that there only be one JavaScript file and that that file has a main function.

OpenWhisk also runs on Node v0.12.9 which does not support any ES6 syntax.

To get around this, and to use arbitrary npm packages when creating our actions, we bundle them with Webpack.

For more information about the motivation behind this example repo, read this blog post.

Methodology

When running in OpenWhisk, the runtime expects there to be an accessible main function. To satisfy this requirement, we set global.main to our main function in index.js. This allows the action to run properly in OpenWhisk despite all of the closures Webpack creates.

What this Example Does

This uses code over multiple files, es6 syntax, and the bluebird promise library. This should cover all the bases for different Webpack use cases. Our OpenWhisk action will take a GitHub username, and then request language data for each repo that user has.

Setup

Make sure you've read through the OpenWhisk getting started docs, then install the dependencies via:

> npm install

Create the Action Bundle

As defined in our webpack.config.js, this will make a minified bundle at dist/bundle.js. To create it we can run the pre-configured script:

> npm run build

or invoke webpack via the command line:

> npm install -g webpack
> webpack --config webpack.config.js --progress --colors

Create an Action on OpenWhisk

From this point on, creating the action is the same as if we had a single js file. All we need to do is point to our bundle:

> wsk action create github-language dist/bundle.js
ok: created action github-language

Invoke the Action

> wsk action invoke --blocking --result github-language --param user 'kauffecup'
{
  "languageArr": [
    {
      "JavaScript": 51019
    },
    {
      "JavaScript": 3083
    },
    {
      "CSS": 1010,
      "HTML": 2666,
      "JavaScript": 8957,
      "Shell": 628
    },
    {
      "JavaScript": 16386
    },
    {
      "JavaScript": 22489
    }
  ]
}