How I'm using GitHub Actions to avoid stale data on this website

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In this post, I'm showing how I leverage a scheduled GitHub Action to automatically rebuild this website just after New Year's Day and avoid stale dates.

The problem

Some of the data on this website (like the current year in the footer) must be updated every time the year changes. However, this site is statically generated using Jekyll which means everything is hard-coded in the generated HTML.

Every year after the new year, I have to remember and manually trigger a rebuild to refresh the current year. This is easy to forget and makes it look like the site isn’t actively maintained anymore, showing an outdated year in the meantime.

I used to use JavaScript to dynamically insert the current year after the page has loaded but never loved this solution: it’s overkill, impacts the performance ever so slightly, and results in a slightly lesser experience for users not running JavaScript.

The solution: automate it!

In my opinion, if something can be automated then it should be: it’s one less thing to forget doing.

GitHub Actions offers scheduled builds which basically function like a hosted cron job. It’s rather burried in the documentation (in my opinion), but it’s there: trigger via schedule.

The idea is to create an action that will run every 1st of January at 00:01 and curl a webhook which will trigger a rebuild.

Netlify build hook

On the Netlify side, I’m using a custom build hook. Because the UI might change over time, please refer to the documentation on exactly how to proceed.

Keeping the hook ID secret

Although I can’t think of anything truly damaging that could happen from triggering a rebuild, I prefer to err on the side of caution and not make the hook public.

Action secrets exist for this purpose, so I’ve put the hook ID into a secret which I can refer to in the action.

Since my action will curl [...] https://<my hook>, it will show the full hook in the logs including the ID that I’m trying to keep secret. Fortunately, I can use a mask and hide it anyway.

The cron string

Using crontab.guru, I came up with the string 1 0 1 1 * to run the action every 1st of January of every year at 00:01.

Giving the build a meaningful title

It’s possible to pass an optional build title when calling the webhook, which will show in the Netlify UI. I’m titling this “Yearly scheduled rebuild” so that it’s clear what triggered the build and I won’t be scratching my head in a few months wondering what happened.

The action

Combining all the above, this is what I get:

# .github/workflows/yearly.yml

name: Update current year on pages

on:
  schedule:
    # On *-01-01 00:01, see https://crontab.guru/#1_0_1_1_*
    - cron: 1 0 1 1 *

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - name: Mask hook ID in logs
        run: |
          echo "::add-mask::${{ secrets.NETLIFY_REBUILD_HOOK_ID }}"
      - name: Trigger site rebuild
        run: |
          curl -X POST -d '{}' https://api.netlify.com/build_hooks/${{ secrets.NETLIFY_REBUILD_HOOK_ID }}?trigger_title=Yearly+scheduled+rebuild

Conclusion

And there we have it, an action that will rebuild the site every year just after the new year so that everything stays up to date, automatically, and without my ever thinking about it again.

Scheduled actions can also be useful to regularly build projects and run smoke tests, automatically close stale issues, generate reports…

If you’d like to explore how automation can save you and your team time building software, send me a message.