Making a blog with Hakyll 2: GitHub Pages & Travis

Posted on Wednesday November 7, 2018

This is a follow-up to my previous post, Making a blog with Hakyll. You don’t need to read it, though; I started over (mostly) from scratch.

As you may have already noticed, this blog is hosted on GitHub pages. This has a number of advantages, the main ones being that I don’t need to worry about hosting and can easily make the blog’s source code available. You can find the source code here.

GitHub pages doesn’t support Hakyll out of the box, but it can serve a static site just fine. I just need to somehow upload Hakyll’s output into Solonarv/solonarv.github.io’s master branch. Fortunately, that’s well within the abilities of a CI service. I chose Travis because it’s the one I’m most familiar with, it’s free, and it has easy GitHub integration. On top of that, Travis has built-in facilities for deploying to GitHub pages, documented here.

Travis expects its configuration in a travis.yml file in the repository’s root directory. Getting Travis to build my site generator and run it is fairly simple:

language: haskell

script: stack build --fast && stack exec -- site build

The deploy section needs a bit more configuration, because my use-case doesn’t exactly fit the default provided by Travis:

deploy:
  provider: pages
  skip-cleanup: true
  github-token: $GITHUB_TOKEN
  keep-history: true
  committer-from-gh: true
  local-dir: _site
  repo: Solonarv/solonarv.github.io
  target-branch: master

This is still fairly straightforward, in my opinion. Let’s see if it works:

$ git add --all
$ git commit
$ git push

Augh! Travis is installing cabal and trying to compile with that! That’s definitely not what I want. Fortunately, a quick search turns up the stack docs, which provide a ready-made .travis.yml. It’s fairly large, so I won’t be including it. Let’s try again.

This first build takes a while (nearly 40 minutes, in fact!), since stack and hakyll’s dependencies need to be set up first; but future builds will be faster, because Travis can cache the results of that work.

Now that I’ve got a successful build, it’s time to get the deployment working. $GITHUB_TOKEN needs to be set to an appropriately-scoped GitHub Personal Access Token, which is easy to set up.

A few minutes later, and… it’s done! That was much easier than I expected it to be. All that’s left is to push the latest version of this very blog post.