Securing Kube Proxy

Kube-proxy runs on every Kubernetes node, enforcing network rules that allow pods, services, and external clients to communicate. Securing kube-proxy is vital to safeguard your cluster against misconfigurations and attacks. In this guide, you’ll learn how to locate and lock down kube-proxy’s configuration, enforce encrypted communication, enable audit logging, and follow security best practices.

1. Locate the Kube-Proxy Process and Configuration

Identify the running kube-proxy and its config file:

joe@ubuntu:~$ ps -ef | grep kube-proxy
root      5351  5134  0 04:22 ?        00:00:04 /usr/local/bin/kube-proxy \
  --config=/var/lib/kube-proxy/config.conf \
  --hostname-override=controlplane --color=auto kube-proxy

The --config flag points to the primary configuration:

apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
bindAddressHardFail: false
clientConnection:
  acceptContentTypes: ""
  burst: 0
  contentType: ""
kubeconfig: /var/lib/kube-proxy/kubeconfig.conf
qps: 0
clusterCIDR: 172.17.0.0/16

The kubeconfig entry specifies where kube-proxy retrieves its API credentials.

2. Secure the kubeconfig File

Protecting the kubeconfig file prevents unauthorized access to the API server.

2.1 Verify Permissions and Ownership

Use a table to validate file permissions and ownership:

File	Permissions	Owner
`/var/lib/kube-proxy/config.conf`	644	root:root
`/var/lib/kube-proxy/kubeconfig.conf`	600 (or 644)	root:root

# Check permission
stat -c %a /var/lib/kube-proxy/kubeconfig.conf
# Check owner and group
stat -c %U:%G /var/lib/kube-proxy/kubeconfig.conf

Always grant the minimum file permissions needed. Restrict write access to root (600) wherever possible.

3. Enforce TLS Encryption for API Connectivity

Open the kubeconfig to confirm TLS settings and service-account authentication:

apiVersion: v1
kind: Config
clusters:
- cluster:
    certificate-authority: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
    server: https://controlplane:6443
  name: default
contexts:
- context:
    cluster: default
    namespace: default
    user: default
  name: default
current-context: default
users:
- name: default
  user:
    tokenFile: /var/run/secrets/kubernetes.io/serviceaccount/token

certificate-authority ensures the API server’s certificate is validated.
server: https://… enforces encrypted HTTPS connections.
Service-account tokenFile grants authenticated, RBAC-controlled access.

4. Enable Audit Logging

Audit logs help you monitor all kube-proxy actions and detect suspicious activity.

Create an audit policy (e.g., /etc/kubernetes/audit-policy.yaml):

apiVersion: audit.k8s.io/v1
kind: Policy
rules:
  # Log all actions by kube-proxy
  - level: Metadata
    users: ["system:kube-proxy"]

  # Optionally monitor changes to core resources
  - level: Metadata
    resources:
      - group: ""
        resources: ["pods", "services", "endpoints"]

  # Skip logging for all other requests
  - level: None

Stream audit events to verify logs:

tail -f /var/log/audit/audit.log | jq .objectRef.resource

Ensure sufficient disk space and retention policies for your audit logs to prevent data loss.

Summary of Best Practices

The image is a summary slide listing five security measures for kube-proxy, including securing config files, encrypting communication, running with least privileges, implementing network policies, and using logging and monitoring.

Secure and limit access to /var/lib/kube-proxy/config.conf and kubeconfig.conf.
Enforce TLS and service-account authentication for API traffic.
Run kube-proxy with least privilege.
Apply NetworkPolicies to control pod-to-pod traffic.
Enable logging and monitoring to detect anomalies.

The image is a summary slide with two points: regularly updating and patching kube-proxy for security, and enabling audit logs to track kube-proxy actions.

Keep kube-proxy updated with the latest security patches.
Enable and review audit logs to track every kube-proxy action.

Watch Video

Securing Container Runtime

Pod Security

Introduction

Overview of Cloud Native Security

Kubernetes Cluster Component Security

Kubernetes Security Fundamentals

Kubernetes Threat Model

Platform Security

Compliance and Security Frameworks

Securing Kube Proxy

1. Locate the Kube-Proxy Process and Configuration

2. Secure the kubeconfig File

2.1 Verify Permissions and Ownership

3. Enforce TLS Encryption for API Connectivity

4. Enable Audit Logging

Summary of Best Practices

Further Reading and References

Watch Video

​1. Locate the Kube-Proxy Process and Configuration

​2. Secure the kubeconfig File

​2.1 Verify Permissions and Ownership

​3. Enforce TLS Encryption for API Connectivity

​4. Enable Audit Logging

​Summary of Best Practices

​Further Reading and References

Watch Video

1. Locate the Kube-Proxy Process and Configuration

2. Secure the kubeconfig File

2.1 Verify Permissions and Ownership

3. Enforce TLS Encryption for API Connectivity

4. Enable Audit Logging

Summary of Best Practices

Further Reading and References