Kubernetes Patterns — Security & Advanced Patterns

The final Kubernetes Patterns discussion focuses on application security and platform extension. It begins with least privilege: a container should not automatically receive root access, a writable filesystem, or unnecessary Linux capabilities. Seccomp helps, but each restriction must reflect what the workload needs.

Kubernetes networking is permissive by default, so policies create deliberate segmentation. For secrets, the group compares encrypted resources in Git, external stores, CSI drivers, and direct retrieval by the application, each with different integration costs and risks for etcd.

Access to the Kubernetes API brings service accounts, RBAC, roles, role bindings, and the danger of an automatically mounted token. The group then turns to reconciliation: small controllers move observed state toward the declared target, while an operator combines them around a larger domain capability.

CRDs provide structured APIs but introduce versioning, validation, and compatibility work; Kubebuilder removes some boilerplate. The finale compares horizontal and vertical scaling, the cluster autoscaler, and Image Builder. The lesson is that secure and elastic behavior depends on explicit constraints and observable control.