Domainly - Custom Domain Infrastructure as a Service

Why SSL Automation Matters

In today's security-conscious digital landscape, HTTPS is not optional—it's mandatory. For multi-tenant SaaS applications supporting custom domains, managing SSL certificates manually is not just impractical; it's impossible at scale. Every new customer domain requires its own certificate, and with certificates expiring every 90 days, manual management becomes a nightmare.

Security First

Modern browsers actively warn users about unencrypted connections, and search engines penalize non-HTTPS sites. SSL automation ensures your customers never experience these issues.

Multi-Tenant SSL Challenges

Multi-tenant applications face unique challenges when it comes to SSL certificate management. Each custom domain requires its own certificate, creating exponential complexity as your customer base grows.

Scale Complexity

Each custom domain requires its own certificate. With hundreds or thousands of customers, manual certificate management becomes impossible.

90-Day Expiration

Let's Encrypt certificates expire every 90 days. Without automation, you'd need to manually renew certificates constantly.

Let's Encrypt & ACME Protocol

Let's Encrypt revolutionized SSL certificate management by providing free, automated certificates with a simple API. The ACME (Automated Certificate Management Environment) protocol is the standard for automated certificate issuance.

Certificate Issuance Process

1
Account Registration: Create an ACME account with Let's Encrypt
2
Certificate Request: Submit a certificate signing request (CSR)
3
Domain Validation: Prove you control the domain through challenges
4
Certificate Issuance: Receive and deploy the signed certificate

Rate Limits

Let's Encrypt has several rate limits you need to consider:

• 50 certificates per registered domain per week
• 300 new orders per account per 3 hours
• 5 failed validations per account per hostname per hour

Implementation Strategies

There are several approaches to implementing SSL automation, each with different trade-offs in complexity, control, and maintenance overhead.

1. Reverse Proxy Integration

Integrate SSL automation directly into your reverse proxy (Nginx, Caddy, Traefik).

# Caddy configuration
*.customer.com {
  tls {
    dns cloudflare
  }
  reverse_proxy app:3000
}

• ✅ Automatic certificate management
• ❌ Tied to specific proxy technology

2. External Service Integration

Use services like Domainly that handle all SSL automation for you.

POST /api/domains
{
  "domain": "app.customer.com",
  "auto_ssl": true,
  "tenant_id": "tenant-123"
}

// SSL automatically provisioned & renewed

• ✅ Zero infrastructure management
• ✅ Built-in monitoring and alerting

Renewal & Monitoring Best Practices

Certificate renewal and monitoring are where automation really shines. Proper implementation ensures certificates are renewed seamlessly without any service interruption.

Renewal Best Practices

Renew at 30 days: Start renewal attempts when certificates have 30 days left
Retry logic: Implement exponential backoff for failed renewal attempts
Hot reloading: Update certificates without service interruption

Monitoring Essentials

• Certificate expiration dates
• Renewal success/failure rates
• Challenge validation times

• SSL handshake performance
• Certificate chain validity
• Rate limit consumption

Security Considerations

SSL automation introduces new security vectors that must be carefully managed to maintain the integrity of your certificate infrastructure.

Critical Security Practices

• Secure ACME account keys with proper encryption
• Validate domain ownership before certificate issuance
• Implement rate limiting to prevent abuse
• Monitor Certificate Transparency logs for auditing
• Use multiple certificate authorities for redundancy

Conclusion

SSL certificate automation is essential for any multi-tenant SaaS application supporting custom domains. By implementing robust automation with proper monitoring, failover strategies, and security practices, you can provide seamless HTTPS security that scales with your business.

The key is to start with a solid foundation using proven tools like Let's Encrypt, implement comprehensive monitoring, and have fallback strategies for when things go wrong. Remember that SSL automation requires ongoing monitoring and maintenance to ensure reliability at scale.

Ready for automated SSL?

Domainly handles all SSL certificate automation for you, including provisioning, renewal, monitoring, and failover. Focus on building your SaaS while we handle the infrastructure complexity.