Or just use traefik or caddy or certbot.
Oncidentally, I wonder how the SSL companies still run when we have the wonderful LE or ZeroSSL. A cert is a free utility today and not worth overthinking.
Totally fair, for public-facing web servers, Traefik, Caddy, and Let’s Encrypt have made things nearly zero-effort. It’s amazing how far we’ve come.
That said, a lot of enterprise environments still deal with: - Air-gapped networks (no LE/ZeroSSL reachability) - Mutual TLS between services, where certs aren’t tied to domains - Manually issued certs from internal or private CAs (often via ticketing systems) - Non-HTTP workloads that don’t play well with ACME automation
In those cases, certs are still a bit of a pain, especially when ownership is unclear or spread across teams. SSL Guardian aims to help in those more chaotic setups, not just the clean webserver use cases.
How does it monitor a cert in an air-gap network?
We're building a lightweight collector (RTCollector) you can run inside the air-gapped environment. It can read from local cert stores (JKS, PKCS#12, PEM, etc.), extract metadata like expiration date and fingerprint (no private keys or cert contents), and send it out securely when outbound connectivity is available.
We already have an api endpoint in place, so you can push data using Python, Bash, curl, or anything else that fits your workflow. No agent required, just a simple POST.
Why would an air-gapped network need public certs? Or how would they update them except manually? Then why would they automate the monitoring?
Just issue them locally (within the airgapped network) and keep track of them based on issue date.
That’s a fair question, and in theory, yes, you could manually track internal certs based on issue date.
But in practice, large or long-running environments rarely have clean cert inventories. You get:
- Internal CA sprawl (and no single source of truth)
Certs embedded in keystores, containers, or staging systems that nobody owns anymore
- “Temporary” certs that live on for years - People leaving without handing off cert responsibilities
We’re not automating monitoring because it’s hard, we’re doing it because teams forget.
And forgetting is what causes outages, broken mTLS, and failed compliance audits, even in air-gapped setups. I have a few horror story on PCI environments.
Automation helps catch the edge cases before they become fire drills.
Ever had your site or API go down because of an expired SSL certificate? It happened to us, and the fix was surprisingly painful. So we built SSL Guardian, a simple, automated SSL/TLS monitoring platform.
What it does:
- Tracks SSL/TLS certificates across all your domains and services - Sends timely alerts (Email, Slack, Webhooks) - Performs chain validation and health checks - Quick setup, zero vendor lock-in
Why? Because one missed renewal can mean hours of downtime, lost trust, and customer churn.
We’re offering free access for early testers (Pro plan for 12 months) in exchange for feedback.
Try SSL Guardian
Would love your thoughts on: - How do you handle SSL/TLS monitoring today? - Biggest pain points you’ve hit? - Features you’d want in a tool like this?
Don't the current monitor solutions do this? Nagios was doing this in 2005. A quick search shows dozens of providers. Hard to see the UVP here.
You’re absolutely right, SSL monitoring isn’t a new problem. Tools like Nagios, Zabbix, and many SaaS providers have offered uptime and cert checks for years.
What I found lacking (especially for modern teams) was: - Multi-domain, multi-tenant tracking with clean dashboards, most tools either require scripting or feel like they’re stuck in 2005.
- Ownership context: who owns which cert, what service depends on it, and whether it’s internal, public, or handled by a vendor.
- Fast visibility for teams with fragmented infrastructure: CDNs, cloud load balancers, custom pipelines, etc.
So yeah, the core idea isn’t new, but the execution is built for today’s hybrid and messy realities. Think of it as Nagios built by someone who has had to explain expired certs to a customer at 6am.
Unrelated to the marketing attempt here but it should be noted that the CA Browser forum voted to drastically shorten certificate lifetimes. Look for 200 day expiration cycles starting next year, 100 days in 2027, and 47 days in 2029.
Absolutely, this shift toward shorter cert lifetimes is going to make monitoring even more critical.
Automation will help, but with 90-, 100-, and eventually 47-day cycles, the margin for unnoticed renewal failures shrinks fast. One bad deploy, broken ACME challenge, or DNS hiccup, and you’re suddenly inside the failure window before anyone notices.
It’s a good time for teams to review their cert workflows, not just issuance, but visibility and alerting too. I built SSL Guardian with that trend in mind, but even if you’re rolling your own monitoring, this change is going to raise the bar for how tightly we need to watch certs.
CAs need to go away. They’re untrustworthy and their inclusion in browsers and OSes seems largely unregulated.
That’s a sentiment I hear a lot, and honestly, not without reason. The trust model behind public CAs is… fragile at best. Misissuances, opaque root store politics, and uneven auditing make it feel like we’re outsourcing security to a cartel.
But until there’s a widely adopted alternative (DANE, peer-to-peer trust, Web of Trust 2.0?), we’re stuck maintaining vigilance within this system. And unfortunately, the shorter cert lifecycles and increasing complexity only make that harder.
I use Caddy, and it handles cert renewal automatically for me, so I've never had to deal with SSL expiry issues. Pretty handy!
Caddy is great for automated cert management, probably one of the cleanest out there.
But in environments where you don’t control the full stack (e.g. legacy infra, third-party APIs, multi-cloud setups), or when certs are provisioned manually or via external teams, things get trickier. Expiry issues still happen more often than we’d like.
That’s what led me to build SSL Guardian, more as a safety net to monitor certs across various sources and alert before things break. Even with automation, having external validation helps avoid blind spots.
In the cases where certificates cannot be automatically issued and renewed, what does this offer that a calendar reminder cannot do?
Certs have built in lifetimes in a standardized format, reading a certs expiration date, setting a calendar reminder X number of days before then and inviting the team responsible for that infrastructure certainly that doesn’t need another tool? Just a check box in the process?
Totally fair, and for a single cert or a tightly controlled setup, a calendar reminder might be “enough.”
But in practice, it tends to break down when:
- Certificates multiply across internal services, vendors, CDNs, load balancers, staging/prod, and even IoT or embedded devices.
Ownership is unclear, people leave, and calendar invites don’t update themselves.
No visibility, unless someone’s checking regularly, you won’t know if a cert was rotated early, replaced with a shorter one, or removed entirely.
No alerting or state tracking, a calendar doesn’t notify you if someone messed up the renewal or if the cert is already expired.
No integration with the rest of your monitoring/incident tooling.
SSL Guardian gives you a real-time dashboard of every cert, expiration tracking, and actual notifications, so you’re not relying on tribal knowledge, calendar hygiene, or someone noticing too late.
We’re not trying to over-engineer a reminder, we’re replacing a fragile human process with something that scales across orgs and environments.
Dont ask me more how I know that a calendar doesn't work lol!
Traefik does certbot autorenewals, really neat
Totally, Traefik + certbot automation works well in many setups.
But I’ve seen cases where cert renewal fails silently (DNS misconfig, HTTP challenge blocked, clock drift, etc.) and no one notices until users start seeing browser warnings.