Namespace Isolation and Multi-Tenancy

Namespace Isolation and Multi-Tenancy

Namespaces provide logical isolation within Kubernetes clusters, serving as security boundaries for multi-tenant environments. However, namespaces alone don't provide strong isolation; they must be combined with RBAC, network policies, and resource quotas to create effective security boundaries. Understanding namespace limitations helps architects design appropriate isolation strategies for their security requirements.

Multi-tenancy in Kubernetes presents unique security challenges. Soft multi-tenancy, where different teams or applications share a cluster, requires careful configuration to prevent interference. Hard multi-tenancy, where untrusted workloads share infrastructure, demands even stronger isolation. Organizations must choose their multi-tenancy model based on trust levels and security requirements, understanding that stronger isolation often comes with increased operational complexity.

Resource quotas and limit ranges provide security benefits beyond resource management. By limiting CPU, memory, and storage consumption, these controls prevent denial-of-service attacks where malicious workloads consume excessive resources. Persistent volume claims can be limited to prevent storage exhaustion. Combined with pod disruption budgets, these controls ensure cluster stability even under attack.