Multi-Subdomain Cloudflare Deployment Guide

César Caldeira

Multi-Subdomain Cloudflare Deployment Guide

Step-by-step production blueprint for deploying Hugo-Carbon with multiple subdomains on Cloudflare Pages and DNS completely for free.

Author: César Caldeira

Published: Aug 24, 2026

Read Time: 4 min

This guide provides a comprehensive, production-ready blueprint for deploying the Hugo-Carbon Modular Engine across multiple isolated subdomains using Cloudflare Pages and Cloudflare DNS at zero monthly hosting cost ($0/mo).

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                    ┌────────────────────────┐
                    │  Cloudflare Anycast    │
                    │      Edge Network      │
                    └───────────┬────────────┘
                                │
        ┌───────────────┬───────┴───────┬───────────────┐
        ▼               ▼               ▼               ▼
┌──────────────┐┌──────────────┐┌──────────────┐┌──────────────┐
│    cesar     ││     blog     ││     apps     ││    carbon    │
│  .caldeira.cc││  .caldeira.cc││  .caldeira.cc││  .caldeira.cc│
│ (Personal)   ││ (Publication)││ (Interactive)││ (Engine/Docs)│
└──────────────┘└──────────────┘└──────────────┘└──────────────┘
        │               │               │               │
        └───────────────┴───────┬───────┴───────────────┘
                                ▼
                    ┌────────────────────────┐
                    │   assets.caldeira.cc   │
                    │   (Shared Static CDN)  │
                    └────────────────────────┘

1. Multi-Target Build Strategy

The Hugo-Carbon project compiles into 5 discrete public directories:

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# Compile each environment into its respective target directory
hugo --environment cesar  -d public/cesar  --cleanDestinationDir
hugo --environment blog   -d public/blog   --cleanDestinationDir
hugo --environment apps   -d public/apps   --cleanDestinationDir
hugo --environment carbon -d public/carbon --cleanDestinationDir
hugo --environment assets -d public/assets --cleanDestinationDir

Automation Shell Script (`scripts/build-all.sh`)

Create an executable build script in your repository root:

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#!/usr/bin/env bash
set -euo pipefail

echo "=================================================="
echo "Compiling all Hugo-Carbon Subdomains..."
echo "=================================================="

export HUGO_ENV="production"

for env in cesar blog apps carbon assets; do
  echo "--> Building target: ${env}..."
  hugo --environment "${env}" -d "public/${env}" --cleanDestinationDir --minify
done

echo "--> Running dependency and license audit..."
python3 scripts/verify-dependencies.py

echo "--> Auditing internal link integrity..."
python3 scripts/test_public_html.py

echo "🎉 ALL SUBDOMAINS COMPILED AND VERIFIED SUCCESSFULLY!"

Make it executable:

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chmod +x scripts/build-all.sh

2. Cloudflare Pages Project Configuration

Cloudflare Pages provides unlimited bandwidth, global SSD edge CDN, automatic SSL certificates, and 500 build operations per month on the Free tier.

Method A: Individual Cloudflare Pages Projects (Recommended)

Create 5 distinct Pages projects linked to the same GitHub repository:

Pages Project Name	Custom Subdomain	Build Command	Output Directory
`caldeira-cesar`	`cesar.caldeira.cc`	`hugo --environment cesar -d public/cesar`	`public/cesar`
`caldeira-blog`	`blog.caldeira.cc`	`hugo --environment blog -d public/blog`	`public/blog`
`caldeira-apps`	`apps.caldeira.cc`	`hugo --environment apps -d public/apps`	`public/apps`
`caldeira-carbon`	`carbon.caldeira.cc`	`hugo --environment carbon -d public/carbon`	`public/carbon`
`caldeira-assets`	`assets.caldeira.cc`	`hugo --environment assets -d public/assets`	`public/assets`

Environment Variables in Cloudflare Pages Dashboard

For each project, navigate to Settings > Environment Variables and add:

HUGO_VERSION: 0.149.0 (or latest extended)
NODE_VERSION: 20.x

3. GitHub Actions Automated Deployment Workflow

Instead of relying on Cloudflare’s native build limits, you can use GitHub Actions to build all 5 subdomains in parallel and deploy them directly using Wrangler.

Create .github/workflows/deploy.yml:

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name: Deploy Multi-Subdomain Hugo-Carbon to Cloudflare Pages

on:
  push:
    branches:
      - main
  workflow_dispatch:

jobs:
  build-and-deploy:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        include:
          - env: "cesar"
            project: "caldeira-cesar"
          - env: "blog"
            project: "caldeira-blog"
          - env: "apps"
            project: "caldeira-apps"
          - env: "carbon"
            project: "caldeira-carbon"
          - env: "assets"
            project: "caldeira-assets"

    steps:
      - name: Checkout Code
        uses: actions/checkout@v4
        with:
          submodules: recursive
          fetch-depth: 0

      - name: Setup Hugo Extended
        uses: peaceiris/actions-hugo@v3
        with:
          hugo-version: "0.149.0"
          extended: true

      - name: Setup Python
        uses: actions/setup-python@v5
        with:
          python-version: "3.12"

      - name: Build Hugo Target
        run: |
          hugo --environment ${{ matrix.env }} -d public/${{ matrix.env }} --minify --cleanDestinationDir

      - name: Verify Link Integrity & Dependencies
        run: |
          python3 scripts/verify-dependencies.py

      - name: Deploy to Cloudflare Pages
        uses: cloudflare/wrangler-action@v3
        with:
          apiToken: ${{ secrets.CLOUDFLARE_API_TOKEN }}
          accountId: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
          command: pages deploy public/${{ matrix.env }} --project-name=${{ matrix.project }} --commit-dirty=true

4. Cloudflare DNS & Custom Domains

In your Cloudflare Dashboard for your domain (caldeira.cc):

1. DNS Records Setup

Add CNAME records with the Proxy status: Proxied (Orange Cloud):

Type	Name	Target	Proxy Status
`CNAME`	`cesar`	`caldeira-cesar.pages.dev`	🟠 Proxied
`CNAME`	`blog`	`caldeira-blog.pages.dev`	🟠 Proxied
`CNAME`	`apps`	`caldeira-apps.pages.dev`	🟠 Proxied
`CNAME`	`carbon`	`caldeira-carbon.pages.dev`	🟠 Proxied
`CNAME`	`assets`	`caldeira-assets.pages.dev`	🟠 Proxied
`CNAME`	`@` (apex)	`caldeira-cesar.pages.dev`	🟠 Proxied

2. Apex Domain Redirection (Page Rules)

To redirect caldeira.cc to https://cesar.caldeira.cc/:

Rule URL: caldeira.cc/*
Setting: Forwarding URL (301 Permanent Redirect)
Destination: https://cesar.caldeira.cc/$1

5. Security Headers, CORS & Performance Optimization

1. CORS Headers for `assets.caldeira.cc`

Because fonts (IBM Plex WOFF2) and scripts are shared from assets.caldeira.cc, Cloudflare must serve appropriate CORS headers.

In the Cloudflare Dashboard, go to Rules > Transform Rules > Modify Response Header:

Rule Name: Allow Cross-Origin Asset CDN
If Incoming Request: Hostname eq "assets.caldeira.cc"
Response Headers:
- Access-Control-Allow-Origin: *
- Access-Control-Allow-Methods: GET, HEAD, OPTIONS
- Timing-Allow-Origin: *

2. Security Headers (Transform Rules)

Add a Response Header rule applied across all subdomains:

X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: camera=(), microphone=(), geolocation=()

3. SSL/TLS and Edge Optimization

In the Cloudflare Dashboard:

SSL/TLS: Set encryption mode to Full (Strict).
Speed > Optimization:
- Enable Brotli compression.
- Enable Early Hints (103 Early Hints).
- Enable HTTP/3 (with QUIC) and 0-RTT Connection Resumption.
Caching > Cache Rules:
- Add a rule for *.woff2, *.css, and *.js: Edge TTL 1 Month, Browser TTL 1 Year.