Best Practices For Securing Your Kubernetes Deployments

Kubernetes has become the most popular platform for deploying and managing containerized applications. However, securing Kubernetes is crucial to avoid security breaches. Here are some best practices for securing your Kubernetes deployments:

Use Role-Based Access Control (RBAC)

• RBAC allows you to assign roles and permissions to users and service accounts. This ensures that users have only the minimum permissions required to perform their jobs.
• Create roles with appropriate rules and bind users/service accounts to those roles. Avoid using overly permissive roles like cluster-admin.
• Use role binding to assign roles to users and service accounts to workloads and pods.

Manage Service Accounts

• Pods use service accounts to interact with the Kubernetes API.
• Limit each namespace and pod’s access by binding them to limited role bindings.
• Automate and rotate service account tokens frequently to reduce the blast radius of a compromised account.

Secure Cluster Network Communications

• Use Transport Layer Security (TLS) for all Kubernetes API traffic.
• Verify API server connections with clearly defined CA certificates.
• Use mutual TLS for authenticating between Kubernetes components.
• Consider using a VPN or private networks for cluster nodes communication.

Enable Kubernetes Audit Logging

• Audit logs record all requests and changes made to your cluster.
• Configure audit logging for the API server and log all events.
• Forward audit logs to a central logging server for monitoring and analysis.
• Tune and filter audit logs to avoid overload while keeping essential events.

Restrict Container Runtime Privileges

• Consider using tools like PodSecurityPolicy to set proper user IDs and capabilities for containers.
• Avoid running containers as root or privileged users whenever possible.
• Set resource limits on CPU, memory, ephemeral storage for namespaces and pods.

Scan Images for Vulnerabilities

• Scan images in registries for known vulnerabilities using tools like Twistlock, Aqua, and Clair.
• Integrate image scanning into CI/CD pipelines to fail builds on vulnerabilities.
• Sign and verify images to ensure integrity through the build pipeline.

Use Network Policies

• Define rules for internal pod-to-pod communications using NetworkPolicies.
• Implement ingress and egress rules to limit network traffic to only allowed sources and destinations.
• Deny all non-essential traffic by default with a default-deny ingress rule.

Encrypt Secrets in Etcd

• Enable encryption of secret data at rest in etcd using a tool like kms-plugin.
• Regularly rotate encryption keys and backup keys externally.
• Verify encryption is enabled across all etcd instances/peers.