Tom Vincent

Essays on hacking, travel and self-improvement

Wintersmith on Heroku

Wintersmith is a static site generator written in Node. This post describes two methods of hosting a Wintersmith-powered site on Heroku. Note, much of this post is analogous to Matthew Manning’s write up for Jekyll/Ruby-powered sites. Thanks Matthew.

We’ll begin with how not to do it:

Wintersmith’s preview server on Heroku

The simplest method of serving a Wintersmith site is by using its built-in web server. The process model of Heroku’s Cedar stack (now the default at the time of writing) makes it really easy to get this up and running quickly.

If you haven’t already, create a Heroku app:

heroku create -s cedar

Next, create a package.json file (at the root of your app), declaring Wintersmith as a dependency:

{
  "name": "node-example",
  "version": "0.0.1",
  "dependencies": {
    "wintersmith": "1.0.x"
  }
}

Next, write a Procfile (again, at the root of your app), declaring Wintersmith as the default web process type:

web: wintersmith preview --chdir public --port $PORT

… replacing public with the directory that contains your site.

Finally, deploy to Heroku and open up your new site in a browser:

git push heroku master
heroku open

Serving static files with Connect

Whilst the previous method works, it is inefficient: in preview mode, Wintersmith generates pages on the fly for every request. Instead, lets make full use of Wintersmith’s build option. Rather than generating pages on the fly, the entire site is generated once as static HTML files. This way, not only is the site much faster, we are free to choose any web server.

Setting up Connect

Here we’ll be using Connect to stay within the Node/Javascript paradigm but feel free to use something else (Rack/Thin might be a good option).

First add Connect to your package.json file:

"dependencies": {
  "wintersmith": "1.0.x",
  "connect": "2.3.x"
}

… and install it with npm install. Also set the web process type (in Procfile) as:

web: node server.js

Connect server

Now we’ll write a minimal web server using the Connect framework. Create a server.js file (at the root of the project) containing the following:

var connect = require('connect');
var port = process.env.PORT || 3000;
var oneDay = 86400000;

connect.createServer(
  connect.compress(),
  connect.logger('short'),
  connect.static(__dirname + '/build', { maxAge: oneDay })
).listen(port);

An important line here is var port = process.env.PORT || 3000; which respects the PORT environment variable set by Heroku. Otherwise, the list of middleware can customised; just refer to the documentation and plug-and-play. Remember to modify the build path to wherever you specify in the following step.

Heroku buildpack

Rather than committing the generated site to the repository, we’ll instead hook into Heroku’s build phase using a custom buildpack. Buildpacks compile our code for execution on each deploy to Heroku.

I’ve forked the default Node.js buildpack, adding one addition to the compile method: the buildpack will check for a Makefile in the project root and call its default task (all) to generate the Wintersmith site.

Firstly, add the buildpack using:

heroku config:add BUILDPACK_URL="https://github.com/tlvince/heroku-buildpack-wintersmith.git#wintersmith"

… then create a Makefile containing the command used to build the site:

all:
  wintersmith build <path>

Any arbitrary shell commands can also be added to the task as necessary.

Testing

Lets test the set up by first building the site using our Makefile and then firing up the Connect server:

make
node server.js

If successful, you should see your blazingly fast site on http://localhost:3000. Monitor the node output to confirm HTTP caching is working correctly.

Finally, deploy to Heroku. You should see the line Node.js: Wintersmith in the output, followed by -----> Building Wintersmith site in the build log.