Let’s Encrypt has ended its certificate expiration reminder emails, making automated SSL certificate renewals essential to maintaining uninterrupted HTTPS for your projects and servers. In this guide, we'll explore how to confidently set up or verify your automated renewal process using Certbot and other ACME clients, along with implementing backup measures to ensure reliability.
Step 1: Choose an ACME Client
The easiest way to automate SSL renewals is through an Automatic Certificate Management Environment (ACME) client. Certbot remains the most popular choice, thanks to its widespread support and user-friendly approach. Since it's the most popular, I'll focus on Certbot for the rest of the article, but the same principles apply to all ACME clients.
- Certbot: Widely supported, easy to configure, and reliable.
- acme.sh: Lightweight shell-script-based option, ideal for advanced users.
- Caddy Server: Web server with built-in automatic HTTPS handling.
Step 2: Set Up Your ACME Client for Automated Renewals
Instructions for certificate issuance vary by platform, and the issuance process is closely tied to auto-renewal.
I'm not going to replicate the detailed instructions here because they'll quickly go out of date, but here are the current links for each of the aforementioned clients:
- Certbot: Certbot instructions
- acme.sh: acme.sh documentation
- Caddy: Caddy automatic HTTPS
Important Notes
I'll mention from recent personal experience: Ensure your system has a cron daemon installed. Some systems, such as Amazon Linux, don't have cron by default, and without it, Certbot's automated renewal jobs will never run!
Also, make sure to restart your server after automated renewal. Certbot handles this in some configurations, but not all. Check our article on how to restart your server after certificate renewal for more details.
Step 3: Implement Backup Checks and Alerts
Although Certbot automatically sets up scheduled renewals, failures can and do still happen to everyone. It's important to add monitoring to catch any issues promptly:
- Check existing Certbot cron jobs/systemd timers (whether you're using timers or cron depends on your configuration) to confirm they're active:
systemctl list-timers certbot.timer
# or
crontab -l | grep certbot
- External Monitoring Services:
Utilize external SSL monitoring services like CertNotifier to receive timely notifications if your certificate approaches expiration or renewal fails.
The Bottom Line
Automation is crucial now that Let’s Encrypt's reminder emails are discontinued. Properly configuring and verifying your automated SSL certificate renewal, alongside backup monitoring measures, ensures continuous security and reliability for your online presence.