Trigger a GitHub Pages Rebuild from Another Repository

My personal website, josephali.dev, is hosted on Github pages, with it's source code stored in the dig/josephali.dev repository.

Whenever I push a change to the main branch, a Github actions workflow builds the Next.js application and deploys to Github pages.

Previously, my TIL notes lived inside the website repository. I wanted to move them into a separate repository dig/notes, while still rebuilding the website whenever a note was added or changed.

The solution was to use a repository_dispatch event that Github supports across repositories.

Dispatching the Event

Inside the dig/notes repository, I created a Github actions workflow exclusively to send the dispatch event whenever a change is pushed to the main branch.

Here's what it looks like:

name: Notify site to rebuild
 
on:
  push:
    branches: [main]
 
jobs:
  dispatch:
    runs-on: ubuntu-latest
    steps:
      - name: Trigger josephali.dev rebuild
        uses: peter-evans/repository-dispatch@v4
        with:
          token: ${{ secrets.REBUILD_PAT }}
          repository: dig/josephali.dev
          event-type: notes-updated

The workflow uses the peter-evans/repository-dispatch@v4 action to send a custom event called notes-updated to the website repository.

Listening for the Event

In the dig/josephali.dev repository, I updated the existing workflow to listen for the dispatch event:

on:
  repository_dispatch:
    types: [notes-updated]

Now, whenever I push a change to the main branch of dig/notes, it sends the notes-updated event to the website repository and starts the build and deploy workflow.

Finally, I added this step to the website build workflow:

- uses: actions/checkout@v4
  with:
    repository: dig/notes
    path: tils

This clones the notes repository and places it at {projectRootDir}/tils. Exactly where the notes were located previously, no code changes needed!