Kubernetes Security

Kubernetes Security #

Kubernetes security is a layered practice across identity, workload configuration, supply chain controls, network boundaries, and runtime monitoring. Do not wait until production to add these controls; build them into the platform path from the first cluster.

Hands-on continuation: Use the Kubernetes Deep Dive: Minikube to AKS/EKS to connect local learning with cloud identity, ingress, observability, and production hardening.

Identity and access #

  • Grant users and automation the minimum RBAC permissions needed.
  • Prefer short-lived cloud identities over long-lived kubeconfig credentials.
  • Separate cluster administration, namespace administration, and deployment roles.
  • Audit privileged actions and high-risk API access.

Workload hardening #

Set secure defaults for every workload:

  • run as non-root
  • drop unnecessary Linux capabilities
  • use read-only root filesystems where possible
  • define resource requests and limits
  • avoid privileged containers and host namespaces unless explicitly approved

Secrets and configuration #

  • Store application secrets in an external secret manager when possible.
  • Encrypt Kubernetes Secrets at rest.
  • Rotate credentials and avoid static cloud keys.
  • Keep secret access scoped to the namespace and service account that needs it.

Admission and policy controls #

Use policy-as-code to reject risky manifests before they run. Common policies require labels, deny privileged containers, enforce image registries, require resource requests, and block hostPath volumes.

Network and runtime controls #

  • Apply NetworkPolicy for namespace isolation.
  • Limit egress from workloads to known dependencies.
  • Scan images in CI and deploy only trusted artifacts.
  • Monitor runtime behavior for suspicious process, network, and file activity.

Security maturity path #

  1. Baseline RBAC and workload security contexts.
  2. Add image scanning, manifest validation, and signed images.
  3. Enforce admission policies for production namespaces.
  4. Integrate external secrets and workload identity.
  5. Add runtime detection, audit review, and incident runbooks.