Setting up Custom Domain for GitHub Pages with Cloudflare

This guide explains how to configure chen.ist and www.chen.ist with Cloudflare DNS for your GitHub Pages site.

Prerequisites: Verify Domain with GitHub

IMPORTANT: Since the repository is owned by the chenist-co organization, you must verify the domain at the organization level, not your personal account.

Get Verification Code from GitHub Organization

  1. Go to your organization settings (not personal account settings):

    • Visit: https://github.com/organizations/chenist-co/settings/pages
    • Or: Click your profile → Your organizations → chenist-co → Settings → Pages

  2. Scroll down to Verified domains

  3. Click Add a domain

  4. Enter chen.ist and click Add domain

  5. GitHub will show you a TXT record like:

    Name: _github-pages-challenge-chenist-co
Value: 01e35f3149aaf97c2579a155192536

    Copy both the name and value - you’ll need them for Cloudflare

Add Verification TXT Record to Cloudflare

  1. Log in to Cloudflare → Select chen.ist → Go to DNS > Records

  2. Click Add record and enter:

    • Type: TXT
    • Name: _github-pages-challenge-chenist-co (or the exact subdomain GitHub provided)
    • Content: (paste the verification code from GitHub)
    • Proxy status: DNS only (gray cloud)
    • TTL: Auto

  3. Click Save

  4. Go back to GitHub and click Verify (may take a few minutes for DNS to propagate)

  5. Once verified, you’ll see a green checkmark ✓

Note: Keep the TXT record in Cloudflare - don’t delete it after verification.

Cloudflare DNS Configuration

IMPORTANT: For GitHub Pages to work properly with Cloudflare, you must disable proxying (use “DNS only” mode - gray cloud icon).

Step 1: Configure Apex Domain (chen.ist)

Add these A records in your Cloudflare DNS settings:

Type Name Content Proxy Status TTL
A @ 185.199.108.153 DNS only (gray) Auto
A @ 185.199.109.153 DNS only (gray) Auto
A @ 185.199.110.153 DNS only (gray) Auto
A @ 185.199.111.153 DNS only (gray) Auto

Step 2: Configure www Subdomain (www.chen.ist)

Add this CNAME record:

Type Name Content Proxy Status TTL
CNAME www chenist-co.github.io DNS only (gray) Auto

Note: The content should be chenist-co.github.io (without trailing dot in Cloudflare)

How to Configure in Cloudflare

  1. Log in to your Cloudflare dashboard
  2. Select your domain (chen.ist)
  3. Go to DNS > Records
  4. Click Add record for each entry above
  5. CRITICAL: Click the orange cloud icon to make it gray (DNS only) for each record
  6. Save your changes

GitHub Repository Configuration

The repository is already configured with: - CNAME file containing “chen.ist” ✓ - Quarto config with site-url: https://chen.ist ✓

Enable Custom Domain in GitHub Pages

IMPORTANT: Only do this AFTER domain verification is complete (green checkmark in account settings).

  1. Go to https://github.com/chenist-co/chenist-co.github.io
  2. Navigate to Settings > Pages
  3. Under Custom domain, enter: chen.ist
  4. Click Save
  5. GitHub will check DNS and show “DNS check successful” when ready
  6. Wait 24 hours, then enable Enforce HTTPS (once certificate is provisioned)

Domain Behavior

With this configuration: - chen.ist → Your main site (apex domain) - www.chen.ist → Automatically redirects to chen.ist - Both domains will work and point to your GitHub Pages site

Verify Setup

After configuring DNS in Cloudflare, verify using these commands:

# Check apex domain A records
dig chen.ist +noall +answer

# Check www subdomain CNAME
dig www.chen.ist +noall +answer

# Verify both domains resolve
curl -I https://chen.ist
curl -I https://www.chen.ist

Expected results: - chen.ist should show the 4 A records (185.199.108-111.153) - www.chen.ist should show CNAME to chenist-co.github.io

Timeline

  • DNS propagation: 5 minutes to 48 hours (typically under 1 hour with Cloudflare)
  • HTTPS certificate: Available 24 hours after DNS propagation
  • Initial setup: Check back in 1 hour to verify the site is accessible

Troubleshooting

Site not loading after DNS configuration

  1. Verify DNS in Cloudflare:

    • Confirm all 4 A records are present for @ (apex)
    • Confirm CNAME record exists for www
    • Ensure Proxy Status is “DNS only” (gray cloud) - this is critical!

  2. Check GitHub Pages:

    • Go to repository Settings > Pages
    • Verify custom domain shows “chen.ist”
    • Check for any warning messages
    • Re-save the custom domain if needed

  3. Clear DNS cache:

    # On your local machine
sudo dnsmasq --clear-cache  # macOS/Linux
ipconfig /flushdns          # Windows

  4. HTTPS issues:

    • Don’t enable “Enforce HTTPS” until the certificate is provisioned
    • Can take up to 24 hours after DNS is working
    • You’ll see a checkmark in GitHub Pages settings when ready

Cloudflare-specific issues

  • ERR_TOO_MANY_REDIRECTS: Proxy status is enabled (orange cloud) - change to DNS only (gray cloud)
  • SSL/TLS mode: Set to “Full” or “Flexible” in Cloudflare SSL/TLS settings
  • Always Use HTTPS: Can be enabled in Cloudflare SSL/TLS > Edge Certificates after GitHub HTTPS is working

Why DNS Only Mode?

GitHub Pages serves content directly and handles HTTPS certificates via Let’s Encrypt. When Cloudflare proxy is enabled: - Cloudflare can’t verify domain ownership for GitHub - Creates redirect loops - Prevents HTTPS certificate issuance

By using “DNS only” mode, Cloudflare only manages DNS resolution, allowing GitHub Pages to work properly.

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