Wildcard SSL Domains

2 min read Updated 1 day ago

Wildcard SSL Domains

Wildcard SSL certificates allow you to secure unlimited subdomains under a single domain with one certificate.

What are wildcard SSL certificates?

A wildcard certificate (*.example.com) automatically secures:

  • app.example.com
  • staging.example.com
  • api.example.com
  • Any other subdomain you create

How it works

  1. Add wildcard domain: Enter your wildcard domain (*.example.com) in your application settings
  2. Configure DNS: Add a CNAME record for certificate validation
  3. Verify and activate: Ploi Cloud verifies your DNS and creates the certificate
  4. Deploy: Redeploy your application to activate the wildcard domain

Setting up wildcard SSL

Step 1: Add your wildcard domain

In your application's Settings tab, find the "Wildcard domains" section and add your domain in the format *.example.com.

Step 2: Configure DNS records

You need to create two DNS records:

For certificate validation (required):

_acme-challenge.example.com → acme.ssl-ploi.cloud (CNAME)

For routing traffic to your application (required):

*.example.com → your-app.test.ploi.it (CNAME)

Step 3: Verify and activate

Once DNS is configured:

  1. Click "Check DNS" to verify your records are correct
  2. Click "Verify & activate" to create the SSL certificate
  3. Redeploy your application to enable the wildcard domain

Important notes

  • One wildcard per application: Each application can have only one wildcard domain
  • Weekly limits: Teams are limited to 5 wildcard domains per week
  • DNS propagation: DNS changes can take up to 48 hours to propagate
  • Certificate renewal: Certificates are automatically renewed before expiration as long as the DNS records are correct.

Troubleshooting

DNS verification fails:

  • Ensure the CNAME record exactly matches the required format
  • Wait for DNS propagation (can take up to 48 hours)
  • Remove any trailing dots from DNS records

Certificate not working:

  • Verify the CNAME record is active
  • Redeploy your application after verification
  • Check that your wildcard domain format is correct (*.example.com)

Subdomains not working:

  • Ensure the wildcard DNS record (*.example.com) points to your application
  • Verify the certificate is active in your application settings
  • Check that subdomains resolve to the correct IP address
  • Wait for DNS propagation (can take up to 48 hours)