Scribbles for my bad memory

Deploying a Flutter web application to GitHub Pages is a straightforward process, but integrating a custom domain can sometimes introduce challenges. Recently, I faced an issue where my Flutter web app, which deployed perfectly to the default GitHub Pages URL, stopped working after setting up a custom subdomain. Here's a step-by-step guide on how I resolved this issue, which might help others facing the same problem.

The Initial Setup

I had a Flutter web app named "HappyNotes" hosted on GitHub Pages. The GitHub Actions workflow used to build and deploy the app looked like this:

name: Deploy HappyNotes Web

on:
  workflow_dispatch:
  push:
    branches:
      - master

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
      - uses: subosito/flutter-action@v2
        with:
          flutter-version: '3.22.x'
          channel: 'stable'

      - name: Build web
        run: |
          cp .env.production .env
          flutter config --enable-web
          flutter build web --release --base-href "/HappyNotes/"

      - name: Deploy to GitHub Pages
        uses: peaceiris/actions-gh-pages@v3
        with:
          github_token: ${{ secrets.RELEASE_TOKEN }}
          publish_dir: ./build/web

This workflow worked flawlessly with the default URL: https://shukebeta.github.io/HappyNotes.

The Problem

After setting up a custom subdomain happynotes.shukebeta.com, the app stopped working. The root cause of this issue involved multiple configuration steps that needed to be adjusted for the custom domain to work properly.

The Solution

Here’s how I resolved the issue:

1. DNS Settings

First, I ensured that the DNS settings were correctly configured:

1. DNS Provider Configuration:

   • Added a CNAME record for happynotes.shukebeta.com pointing to shukebeta.github.io. (attention: the last . after io is important!)

2. GitHub Pages Configuration

Next, I checked the GitHub Pages settings:

1. Custom Domain Setup:

   • Navigated to the repository’s settings on GitHub.
   • Under the "Pages" section, set the custom domain to happynotes.shukebeta.com.
   • Enabled "Enforce HTTPS".

3. CNAME File

To ensure GitHub Pages recognized the custom domain, a CNAME file will be needed to put into the build/web directory. I automated this step in the GitHub Actions workflow:

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v4
      - uses: subosito/flutter-action@v2
        with:
          flutter-version: '3.22.x'
          channel: 'stable'

      - name: Build web
        run: |
          cp .env.production .env
          flutter config --enable-web
          flutter build web --release --base-href "/"

      - name: Create CNAME file
        run: echo 'happynotes.shukebeta.com' > ./build/web/CNAME

      - name: Deploy to GitHub Pages
        uses: peaceiris/actions-gh-pages@v3
        with:
          github_token: ${{ secrets.RELEASE_TOKEN }}
          publish_dir: ./build/web

4. Base URL Adjustment

Since the custom subdomain serves the app from the root, the base-href parameter is also needed to adjust:

- name: Build web
  run: |
    cp .env.production .env
    flutter config --enable-web
    flutter build web --release --base-href "/"

that's it.