gabrielkaszewski-next/docs/superpowers/plans/2026-05-16-dual-domain.md

Dual-Domain Support Implementation Plan

For agentic workers: REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (- [ ]) syntax for tracking.

Goal: Serve the portfolio on both gabrielkaszewski.dev and gabrielkaszewski.pl with identical content, with .dev as the canonical domain for SEO.

Architecture: Two independent changes — Traefik routing config to accept both hostnames, and Next.js metadata to inject a canonical <link> tag. No app logic changes.

Tech Stack: Next.js 15 (App Router metadata API), Traefik (Docker labels), Let's Encrypt TLS.

---

Task 1: Add .pl domain to Traefik router

Files:

• Modify: compose.yml

• Step 1: Update the Traefik router rule

In compose.yml, change the router rule label from:

- "traefik.http.routers.gabrielkaszewski.rule=Host(`gabrielkaszewski.dev`)"

to:

- "traefik.http.routers.gabrielkaszewski.rule=Host(`gabrielkaszewski.dev`) || Host(`gabrielkaszewski.pl`)"

The full labels block should look like:

labels:
  - "traefik.enable=true"
  - "traefik.http.routers.gabrielkaszewski.rule=Host(`gabrielkaszewski.dev`) || Host(`gabrielkaszewski.pl`)"
  - "traefik.http.routers.gabrielkaszewski.entrypoints=websecure"
  - "traefik.http.routers.gabrielkaszewski.tls.certresolver=letsencrypt"

Note: Traefik's Let's Encrypt cert resolver automatically provisions a cert for every hostname matched by the router rule, so no additional TLS labels are needed.

• Step 2: Commit

git add compose.yml
git commit -m "feat: add gabrielkaszewski.pl to traefik router"

---

Task 2: Add canonical URL to Next.js metadata

Files:

• Modify: app/layout.tsx

• Step 1: Add alternates.canonical to the metadata export

In app/layout.tsx, add alternates to the existing metadata object:

export const metadata: Metadata = {
  title: {
    default: "Gabriel Kaszewski | Software Engineer",
    template: "%s | Gabriel Kaszewski",
  },
  description:
    "The portfolio of Gabriel Kaszewski, a software engineer specializing in Rust, Python, and modern web technologies.",
  keywords: [
    "Gabriel Kaszewski",
    "Software Engineer",
    "Rust Developer",
    "Python Developer",
    "Next.js",
    "Portfolio",
  ],
  alternates: {
    canonical: "https://gabrielkaszewski.dev",
  },
  openGraph: {
    // ... rest unchanged
  },
  // ... rest unchanged
};

• Step 2: Verify the canonical tag is present in the built HTML

Run the dev server:

bun run dev

Then in another terminal, check the rendered HTML for the canonical tag:

curl -s http://localhost:3000 | grep -i canonical

Expected output:

<link rel="canonical" href="https://gabrielkaszewski.dev"/>

• Step 3: Commit

git add app/layout.tsx
git commit -m "feat: add canonical URL to metadata"