Github Pages, Gatsby, And Custom Domains

AKA. of CNAMEs and Men

I recently switched over my site built with Gatsby and hosted via Github Pages to use my custom domain. Previously I had been publishing the output directory public directly to the gh-pages branch with the following subtree command:

git subtree push --prefix public origin gh-pages

Many thanks to Guilherme Ferreira and some others for this trick.

However, as I said above, I decided to pull the lever on my site and drop this new hotness into my custom domain “andrewdc.com.” I added the domain via the github web ui following some instructions somewhere.

Don’t do it this way

The issue you will run into is that this creates a CNAME file in your gh-pages branch. Not a big deal until you try to run your elite subtree h4xxor command again and git barfs this error up in your base:

git push using:  origin gh-pages
To github.com:andrewdc/adc.git
 ! [rejected]        5d5a6054db232f5e33e1e5840c1355859e6d8850 -> gh-pages (non-fast-forward)
error: failed to push some refs to 'git@github.com:andrewdc/adc.git'
hint: Updates were rejected because a pushed branch tip is behind its remote
hint: counterpart. Check out this branch and integrate the remote changes
hint: (e.g. 'git pull ...') before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.

ouch…

It makes sense though, because the Github web interface is creating a file that isn’t tracked by your local stuff, and is outside of your process.

The Solution?

Simply add your own CNAME file into your output directory (mine is /public) and then run your subtree push. If, like me, you already totes borked your gh-pages branch you can wipe it out with:

git push origin :gh-pages

Then try git subtree push --prefix public origin gh-pages again.

Thanks so Sacha Greif and of course Kyle Mathews. Full discussion here on Github.

Bonus: Add a build and subtree push npm run deploy command to your package.json

"scripts": {
 ...
  "deploy": "gatsby build && git subtree push --prefix public origin gh-pages"
},

Hack on, Friends!

~adc