Automate SSL Certificate Expiry Checks with These Easy Tools

What are SSL Certificates?

They are the Digital Certificates that validate the Certificate Expiry, enabling the encrypted communication over the internet using the HTTPS.

SSL Certificates are issued by the Certificate Authorities, like

Let's Encrypt (Free with Automated Domain Validations(DV))

ZeroSSL (Free Alternative to Let's Encrypt(For DV) )

DigiCert (Best for Enterprises)

GlobalSign (Enterprise, IOT Focused Applications)

GoDaddy (Best for Small Businesses)

Types of SSL Certificates ?!

Domain Validation (DV)

• This certificate gets issued the fastest and proves that we control the domain

• Comes with basic encryption and requires no legal verification.

Organization Validation (OV)

• It is encrypted like the DV, but it requires the business identity

• While legal verification is required with checks like Business name, Address, Phone, Legal Existence

• Takes 1-3 Days to be issued

Extended Validations (EV)

• The Certificate Authority checks rigorously for legal, physical, and operational details.

• It takes around 3-5 days to issue and is considered ideal for financial sites.

SAN Certificate (Multi-Domain Certificate)

• It lets us secure multiple domains under one certificate.

• Like example.com, www.example.com, example.net, shop.example.com

• It can work efficiently with the DV, OV, or EV

Wildcard Certificate

• It covers all the subdomains under one domain.

• Syntax: *.yourdomain.com (works for www, api, app, etc.)

• It works great for apps with multiple modules like Google applications comprising of Gmail (mail.google(dot)com), Drive (drive.google(dot)com)

Why do we need to monitor SSL Certificates ?!

• Prevent website outages and browser warnings.

• Avoid trust issues with end users.

• Enable smooth automation for certificate renewal (especially Let's Encrypt).

Monitor SSL Expiry with Uptime Kuma (Automated Approach)

Uptime Kuma is an open-source, easy-to-use, self-hosted monitoring tool generally used to monitor on-prem resources.

Features

• Able to monitor the Uptime for HTTP(s)/TCP, HTTP(s) JSON Query, Ping, DNS Record, Push, Stream Game Server, and even Docker Containers.

• It can provide notifications via Telegram, Slack, Email, and 90+ notification services.

• GOOD UI Dashboard and supports 2 Factor Authentication.

Prerequisites for the Setup

• Docker or Node.js environment

• Access to the domain you want to monitor (basically need to own a domain/ have access to that domain)

Demo for Setting Uptime Kuma:

Step 1: Deploy Uptime Kuma using Docker

# Create a Volume named as uptime-kuma
docker volume create uptime-kuma

# Run the Container
docker run -d \
  --restart=always \
  -p 3001:3001 \
  -v uptime-kuma:/app/data \
  --name uptime-kuma \
  louislam/uptime-kuma

Check out the Browser with the port 3001 (on which the uptime kuma dashboard will run)

If you want to get a quick hands on you can make use of the demo session also.

Step 2: Add an HTTPS Monitor

• Click "+ Add New Monitor"

• Monitor Type: HTTPS

• Friendly Name: Domain Certificate Expiry

• URL: https://yourdomain.com

Step 3. Set up Notification Alerts

We can add setting up the notification integration like email, telegram, Slack / Discord, gotify, etc.

Step 4. Monitor & Get Notified

Uptime Kuma will now:

• Periodically check the SSL cert.

• Alert you when the certificate is about to expire.

Other Ways to Monitor SSL Certificate Expiry

Using OpenSSL or curl (Manual Way)

Using them in a shell script to determine if the SSL certificate has expired, and can be combined with email notification or Slack webhook.

openssl s_client -connect YOUR_DOMAIN_HERE:443 -servername YOUR_DOMAIN_HERE </dev/null 2>/dev/null \
| openssl x509 -noout -enddate

Using Monitoring Platforms (Highly Preferred Way)

• Add cert monitoring as a feature of your existing monitoring setup (Cluster Monitoring Setup).

• Popular Automated Approaches include the Prometheus + Blackbox Exporter, Datadog, NewRelic, and Dynatrace

Using the DNS + Certificate Providers

• Use Let's Encrypt expiry hooks.

• Many DNS providers or CDNs (e.g., Cloudflare, AWS ACM) offer expiry monitoring or auto-renewals.

• Use ACME clients like certbot with post-renew hooks to notify you if it fails.

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Conclusion

SSL cert expiry isn’t just a warning; it’s downtime, broken trust, and leads to a potential revenue loss. Dosen't matter if you're a solo dev, running a SaaS, or managing Kubernetes at scale, automating SSL checks isn't optional, it's a DevOps ritual.

From Uptime Kuma’s plug-and-play ease to Prometheus-powered precision, you’ve got options. Pick your stack, set your alerts, and sleep like your certs aren’t about to explode.

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