Just went through our annual SSL certificate renewal scramble for our WAF and CDN assets. As usual, it was a manual, error-prone process logging into the portal, downloading CSRs, coordinating with the cert team, and uploading. Took half a day and carried real risk of an outage if we missed something.
Turns out Imperva has a fully functional API for this. We built a script that:
* Lists all the applications and their current cert expiry dates.
* Generates the new CSR via API call.
* Sends the CSR to our internal CA for signing.
* Uploads the signed certificate and chain back via API.
The entire process is now automated and runs 30 days before expiry. No human intervention needed. Key things we had to get right:
* API key permissions require the "Manage SSL" privilege.
* The chain upload order is specific (server cert first, then intermediates).
* You must trigger a "propagation" API call after upload to push it to the edge.
This isn't documented in the most obvious places, but the API endpoints are there and stable. Saved us hours of manual work and eliminated the outage risk. If your org has more than a handful of certificates, automate it. The API reliability on this has been solid for us over the last two cycles.
—Chloe
SLA is not a suggestion.
Interesting, and I'm sure your script works perfectly in a lab. But let's talk about that "API reliability" you glossed over. What's your actual SLO for that Imperva endpoint? What happens when it's down for an hour during your automated 30-day-before-expiry run? Your script probably crashes, emails someone, and now you have a manual problem again with less runway.
Did you build in idempotency and circuit breakers, or is it just a cron job hitting a POST endpoint and praying? I've seen these "stable" vendor APIs vanish or change without warning, leaving a trail of expired certificates. The manual process was a pain, but at least it forced someone to look at the system once a year.
Your k8s cluster is 40% idle.
You've raised a critical point about assuming API stability. It's not a cron job praying to a POST endpoint. A production implementation needs a state machine. Ours tracks each asset's renewal in a small database with statuses like 'pending_csr', 'awaiting_ca', 'upload_retry'. The initial check happens at 45 days out, not 30, specifically to absorb API outages or retry loops.
Idempotency is handled by checking the existing expiry date before any CSR generation, and the upload step validates the new certificate's fingerprint against what was requested. Circuit breakers are implemented at the script level - if more than 25% of the batch calls fail, it halts and escalates. The manual process didn't go away; it just moved from routine execution to exception handling, which is a proper trade-off.
You're right that vendor APIs can change. That's why the script is wrapped in version checks and its API calls are isolated into a single library module. A failure there is a different class of alert than a transient 503.
That propagation step after uploading the chain is a critical detail I've seen trip people up. Without it, you think you're done but the old cert is still active on the edges.
If anyone else is scripting this, consider adding a verification step that polls for the new certificate's fingerprint after calling propagation. It's saved us from thinking a renewal succeeded when it actually failed silently on a particular PoP.