Monitor Cilium with Datadog

Cilium is an open source technology that provides network security to containerized environments at both packet and application levels. It integrates seamlessly with Kubernetes clusters and Docker environments using Mesos. Traditional firewalls filter traffic based on IP address and port, but Cilium overcomes this by using the Linux kernel's Berkeley Packet Filter (BPF) to enforce security policies using container identities or abstractions like Kubernetes service or pod. Datadog now integrates with Cilium to help users ensure their network policies are properly deployed and enforced, providing visualization and alerting on key metrics exposed by the Cilium Agent and Operator. The integration allows for tracking endpoint health and lifecycle events, monitoring endpoint regeneration duration, identifying when packets are dropped, and detecting issues with policy imports.