Security Operations in Azure Kubernetes Service (AKS)

This document provides guidance on implementing and maintaining robust security practices for your Azure Kubernetes Service (AKS) clusters. Security is a shared responsibility between Azure and your organization, and AKS offers several features and configurations to help you secure your workloads.

Key Security Areas

1. Cluster Security

Securing the control plane and worker nodes is fundamental. AKS manages the control plane, but worker nodes and their configurations are your responsibility.

  • Network Security: Implement network policies, use Azure Firewall with AKS, and configure Private Clusters.
  • Node Security: Keep nodes patched, use secure base images, and restrict direct node access.
  • API Server Access: Control access to the Kubernetes API server using Azure Active Directory (Azure AD) integration and RBAC.

2. Workload Security

Protecting your applications running within AKS is crucial. This involves securing container images, managing secrets, and enforcing runtime security.

  • Container Image Security: Scan images for vulnerabilities, use trusted registries, and sign images.
  • Secret Management: Use Azure Key Vault or Kubernetes Secrets securely. Avoid hardcoding secrets.
  • Pod Security Standards: Enforce security best practices for pods using Pod Security Admission or OPA Gatekeeper.
  • Network Policies: Isolate pods and control network traffic flow between them.

3. Identity and Access Management

Properly managing identities and their permissions is key to a secure AKS environment.

  • Azure AD Integration: Integrate AKS with Azure AD for centralized authentication and authorization.
  • Role-Based Access Control (RBAC): Implement fine-grained access control for Kubernetes resources using RBAC.
  • Managed Identities: Assign managed identities to pods for secure access to Azure resources.

4. Monitoring and Auditing

Continuous monitoring and auditing are essential for detecting and responding to security threats.

  • AKS Diagnostics: Utilize AKS diagnostics to gather logs and metrics.
  • Azure Monitor: Integrate with Azure Monitor for centralized logging and alerting.
  • Audit Logs: Enable and review Kubernetes audit logs for suspicious activities.
Tip: Regularly review your security configurations and update them as new threats emerge.

Implementing Security Best Practices

Network Security Example: Network Policies

Network policies allow you to control the traffic flow at the IP address or port level, similar to how a network firewall works. By default, pods in an AKS cluster can send and receive traffic without restriction. Network policies are Kubernetes resources that define rules for how groups of pods are allowed to communicate with each other and other network endpoints.


apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: deny-all-ingress
  namespace: default
spec:
  podSelector: {}
  policyTypes:
  - Ingress

The above policy denies all ingress traffic to all pods in the 'default' namespace. You can then create more specific policies to allow desired traffic.

Identity and Access Management Example: Azure AD Integration

Integrating AKS with Azure AD simplifies user and group management. You can assign roles to Azure AD users or groups, which then map to Kubernetes RBAC roles.

Note: Ensure you have the correct Azure AD permissions and RBAC roles configured in AKS for effective integration.

Advanced Security Features

  • Azure Policy for AKS: Enforce organizational standards and assess compliance across your AKS clusters.
  • Security Center: Leverage Azure Security Center for advanced threat detection and security posture management.
  • Confidential Computing: Explore confidential computing options for highly sensitive workloads.
Important: Implementing a comprehensive security strategy requires a multi-layered approach, combining Azure's built-in security features with your organization's policies and procedures.

For more in-depth information on specific security topics, please refer to the relevant sections in the AKS documentation.