How do I automate SSL certificate renewal?

If you're using Azure, don't worry too much. Azure manages auto-renewal of certs for you every six months, so you're good there!

A solid way to handle SSL cert renewals is by using a Key Vault connection to your certificate provider with managed identities for VMs and app gateways. This setup allows certificates to be automatically renewed and placed in the Key Vault, ensuring your servers and app gateways are updated in just minutes after renewal.

Using ACME-based certs is the way to go. If your certs aren't provided for free by Azure or AWS, you can automate the renewal with a script that injects them via API for any vendor apps you’re using. Managing certificates can be self-sufficient and cost-effective with the right setup.

For a complete automation, try using tools like Certbot, or if you're in Kubernetes, cert-manager can handle renewals without any manual effort. Caddy and Traefik are also great proxies that automate SSL renewals effortlessly!

I would steer clear of using the integrated Key Vault option unless you absolutely need the reputation of places like GlobalSign or DigiCert. It's pricey and can run up your bill. Instead, I recommend using Let's Encrypt – you can run it with various clients or scripts that work with Key Vault. Make sure your DNS provider supports the necessary API for the DNS-01 challenge; if not, you might want to look into switching providers.