Domain dns ops

Domain/DNS Ops

Attribution: Sourced from steipete/agent-scripts by Peter Steinberger.

When to Use

• Setting up DNS zones and records on Cloudflare
• Configuring vanity domains, redirects, and nameserver delegation
• Verifying DNS propagation and HTTP redirect chains

Golden Path (new vanity domain → Cloudflare → redirect)

1. Decide routing model

   • Page Rule redirect (small scale, per-zone).
   • Bulk Redirects (account-level).
   • Worker route (fallback).

2. Cloudflare zone

   • Create zone in Cloudflare dashboard, then confirm:

     curl -s "https://api.cloudflare.com/client/v4/zones?name=example.com" \
       -H "Authorization: Bearer $CLOUDFLARE_API_TOKEN" | jq '.result[0] | {id, name, status}'
     

3. Nameservers

   • Update nameservers at your registrar to Cloudflare's NS records.

4. DNS placeholders (so CF can terminate HTTPS)

   • Proxied apex A → 192.0.2.1 (placeholder)
   • Proxied wildcard A → 192.0.2.1

5. Redirect setup

   • Page Rule: destination URL + 301 permanent redirect.
   • Or use Cloudflare Bulk Redirects for multiple domains.

6. Verify

# DNS check
dig +short example.com @1.1.1.1

# HTTPS redirect
curl -I https://example.com
# Expect: HTTP/2 301 or 302 with Location header

Common Commands

# Check if domain resolves to Cloudflare
dig +short example.com @1.1.1.1

# Check HTTP/HTTPS redirect
curl -sIL https://example.com | grep -E "HTTP/|Location:"

# Check DNS propagation
dig +short example.com @8.8.8.8
dig +short example.com @1.1.1.1

Guardrails

• Confirm registrar before debugging Cloudflare "invalid nameservers" (often "wrong registrar").
• Prefer reversible steps; verify after each change (NS → DNS → redirect).
• Do not print API tokens or secrets.