SSL expiry : monitor your cert

The Story

Recently, a customer of mine called me in a hurry because he needed assistance to renew their SSL certificate on his messaging infrastructure. They just forgotten to acquire and install a new cert and nobody is able to connect anymore. The house is on fire!

What ?!

In 2019, we all know that SSL certificate have a certain duration and to avoid such problems, good IT teams usally register it in in their ITSM toolset : contract management or just in a team/shared calendar to remind this task. Even better, smart teams (DevOps) are trying to automate most of the process and use the free services of LetsEncrypt.

Anyway, this situation gave me an idea and I started the developpement of a tool to help them.

About Lametric TIME

Lametric TIME benefits of beautiful 8-bits design. Its main function is a (alarm) clock and web-radio player. You can install a couple of apps, from the Lametric Store. This device could also be used to count the number of followers on social networks, display the Weather forecasts (NetAtmo or others) or even some news.

LamtricTIME can also be integrated in your IFTTT (If This Then That) scenarios : it also explains why the device is popular and used by IoT fans.

In March 2018, I published a post on this blog about a first app, created to display Exoscale services status.

SSL expiry is the second app written. It will be open-sourced in a few days and available on usual public repository (Github or Gitlab).

The public API

I created a public API to display the remaining days before the expiry of your public certificate.

  • Method : GET
  • URL : https://certificate.pittet.org/api/v1
  • Mandatory parameters : hostname (i.e. lametric.com) and port (i.e. 443)

https://certificate.pittet.org/api/v1?hostname=sebastien.pittet.org&port=443

The App

It can be found on Lametric app store : https://apps.lametric.com/apps/ssl_expiry/8659.

Once added to your Lametric TIME, the app has to be configured with your settings (hostname and port).

Web Application

A frontend is also available at: https://certificate.pittet.org

Result

The remaining days before expiry will then be displayed, as shown below.

Some notes & comments:

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