How to Monitor CoreDNS

CoreDNS is a flexible DNS add-on for Kubernetes environments, introduced in Kubernetes 1.11 as an alternative to the kube-dns add-on, and is crucial for the seamless operation of Kubernetes clusters by resolving domain names and facilitating IPs for internal and external services and Pods. Monitoring CoreDNS is essential, given its role in DNS service discovery, and can be effectively performed using Prometheus to scrape and analyze metrics like error rates, latency, traffic, and saturation from CoreDNS endpoints. The single-container setup of CoreDNS, as opposed to the three-container kube-dns, resolves several issues, including security vulnerabilities and stub domains for external services. Prometheus configurations allow for monitoring these metrics, and tools like Sysdig Monitor can further streamline the process by providing out-of-the-box dashboards and accelerating troubleshooting. This ensures that Kubernetes infrastructure remains healthy, supporting the proper functioning of applications and services across varied IT architectures.