How to Set Up Falco for Runtime Security in Kubernetes

Most Kubernetes security controls act before a workload runs. Image scanners check for known vulnerabilities at build time. Admission controllers reject pods with dangerous settings at deploy time. Network policies restrict which connections are possible. All of these are valuable, and none of them can tell you what a container is actually doing once it is running. A container built from a clean image, admitted by every policy and sitting behind a tight network policy can still be compromised through an application vulnerability, a stolen credential or a malicious dependency that only misbehaves at runtime.

Falco fills that gap. It is an open-source runtime threat detection engine, originally created by Sysdig and now a graduated project in the Cloud Native Computing Foundation. It observes system calls and other event streams on each node, evaluates them against a rule set, and raises alerts when behaviour matches a pattern you have defined as suspicious: a shell opening inside a production container, a process reading a credentials file it has no reason to touch, or a binary being written to a directory that should be read-only. This guide explains how Falco works, how to roll it out without drowning in noise, and how to route and respond to its alerts.

DETECTION, NOT PREVENTION