About

verify-k8s-certs is a daemon (prometheus exporter) to discover expired TLS certificates in a kubernetes cluster. It exposes the informations as Prometheus metrics that can be scraped.

Build & dockerize

Build the daemon:

go build -o verify-k8s-certs

Build the docker image:

docker build -t verify-k8s-certs .

How to run

• Be sure to run the daemon as a kubernetes deployment, you should also expose it as a service so Prometheus can scrape the metrics from its endpoints.
• The deployment needs permission to list all the namespaces and all the services of the cluster so be sure to use a serviceaccount with these privileges otherwise it will not work!
• When the deployment is successfully deployed on the cluster and runs with no errors then you should add to the scrape_config section of your Prometheus instance a new job to instruct it to scrape the metrics.

Metrics

The exposed Prometheus metrics are the following ones (at the endpoint /metrics):

• (gauge) tls_verifier_seconds_to_expiration_tls_certificate: how many seconds are left to the expiration of the certificate for the services
• (gauge) tls_verifier_discovered_tls_certificates_of_services: how many TLS certificates have been discovered in the exposed services of the cluster
• (counter) tls_verifier_heartbeat: just a counter that keeps increasing, it can be used to detect if the daemon is healthy or not

Author

Angelo Poerio angelo.poerio@gmail.com