Network Policy
Network Policies are a mechanism to control network traffic flow within and from/to Kubernetes clusters.
With the Rafay blueprint, all namespaces are locked down with a default network policy that blocks all resources in the namespace to exchange network traffic with "other namespaces" and "outside the cluster"
| # | Primary Threat Vectors | Default Policy |
|---|---|---|
| 1 | Rogue container tries to connect to resources in other namespaces | BLOCKED |
| 2 | Rogue container tries to connect to resources outside cluster to exfiltrate data or download malicious software | BLOCKED |
Shown below is a screenshot of what network policy enforcement looks like in Rafay
Note
Learn more about Network Policy Enforcement in the Rafay platform.
Why is it needed?¶
Network policies are crucial for multi-tenant environments because of the following reasons:
Isolation Between Tenants¶
- Security Boundaries: In a multi-tenant environment, different teams, departments, or organizations share the same Kubernetes cluster. Network policies help enforce isolation between tenants by controlling which pods can communicate with each other across different namespaces. Without network policies, there could be unintended or unauthorized cross-tenant communication, potentially leading to data leaks or security breaches.
- Namespace Segmentation: Network policies can restrict traffic between namespaces, ensuring that each tenant's workloads are isolated from others. This is particularly important for maintaining the confidentiality and integrity of data and applications within each tenant's namespace.
Enhanced Security Posture¶
- Minimizing Attack Surface: By default, Kubernetes allows unrestricted communication between pods within the same cluster. Network policies allow administrators to restrict this communication, minimizing the attack surface by only allowing necessary traffic. This reduces the risk of lateral movement by attackers within the cluster.
- Preventing Data Exfiltration: Network policies can be configured to block traffic from sensitive workloads to the internet or other untrusted networks, preventing unauthorized data exfiltration and ensuring that sensitive data remains secure within the cluster.
Compliance and Regulatory Requirements¶
- Data Protection: Many industries have stringent regulations around data protection, particularly when dealing with multi-tenant environments. Network policies help ensure that only authorized communication occurs within the cluster, which is crucial for meeting compliance requirements such as GDPR, HIPAA, or PCI-DSS.
- Auditable Controls: Implementing network policies provides auditable controls over network traffic, which is often required for regulatory compliance. This helps demonstrate to auditors that appropriate measures are in place to protect data and control access.
Traffic Management¶
- Controlled Communication: Network policies enable fine-grained control over pod-to-pod and pod-to-service communication, ensuring that only essential traffic flows within the cluster. This can help optimize network performance and reduce unnecessary traffic, leading to more efficient use of resources.
- Service Isolation: Critical services can be isolated from non-essential or less secure services using network policies, ensuring that high-value services have the necessary protection and performance guarantees.
Mitigating Misconfigurations¶
- Preventing Miscommunication: In complex multi-tenant environments, it’s easy to misconfigure applications or services, leading to unintentional exposure of sensitive data. Network policies act as an additional layer of defense, ensuring that even if there’s a configuration error, unauthorized traffic is still blocked.
- Default-Deny Posture: By implementing a "default-deny" network policy, administrators can ensure that no communication is allowed unless explicitly permitted. This proactive approach helps mitigate the risk of accidental exposure due to misconfigurations.
Supporting DevOps and Microservices¶
- Service Mesh Integration: In environments where service meshes are used for managing microservices, network policies provide an additional layer of security. They can work alongside service mesh policies to enforce security at both the network and application layers.
- CI/CD Pipeline Security: For DevOps pipelines that deploy workloads into a multi-tenant cluster, network policies ensure that only authorized and intended communications occur, protecting the pipeline and the deployed applications from potential security threats.
Protecting Shared Infrastructure¶
- Safeguarding Core Services: Network policies can protect shared infrastructure components (like databases, monitoring systems, or logging services) by ensuring that only authorized pods from specific namespaces can access them, preventing unauthorized access from other tenants.
- Limiting Blast Radius: If a tenant's application is compromised, network policies can limit the impact (blast radius) of the breach by preventing the attacker from spreading to other parts of the cluster.
In summary, network policies are essential in a multi-tenant environment to enforce isolation, enhance security, comply with regulations, and manage traffic effectively. They provide a necessary layer of control that ensures tenants can coexist securely within the same host cluster.