Custom Domain Setup

2a. Accept wildcard hostnames

The load balancer (nginx / Caddy / ALB) must accept any Host header — not just known subdomains.

# nginx example
server {
    listen 443 ssl;
    server_name _;                         # catch-all — accept any hostname

    ssl_certificate     /etc/ssl/certs/wildcard.pem;
    ssl_certificate_key /etc/ssl/private/wildcard.key;

    location / {
        proxy_pass         http://jms-api:3000;
        proxy_set_header   Host              $host;
        proxy_set_header   X-Real-IP         $remote_addr;
        proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Proto $scheme;
    }
}

2b. React frontend (SPA)

Custom domains point at the same static host that serves the JMS SPA. All non-API paths should serve index.html (standard SPA fallback). nginx must redirect bare custom domain requests to the /public/domain route.

server {
    listen 443 ssl;
    server_name _;

    root /var/www/jms-frontend/dist;
    index index.html;

    location /api/ {
        proxy_pass http://jms-api:3000;
        proxy_set_header Host $host;
    }

    # Redirect bare custom domain to /public/domain route
    location = / {
        return 302 /public/domain;
    }

    location / {
        try_files $uri $uri/ /index.html;
    }
}

Option A — Let's Encrypt with cert-manager or Caddy (recommended)

Use automatic TLS issuance. The journal owner points the CNAME, then the platform provisions a cert on the first HTTPS request.

• Caddy: built-in automatic TLS. Just use server_name _ — Caddy handles everything automatically.
• cert-manager (k8s): deploy an Issuer that uses the HTTP-01 or DNS-01 ACME challenge. A short cold-start delay (< 30s) on the very first request is expected.

Option B — Wildcard certificate