Monitoring Security Issues in Kubernetes

This Go project creates a Kubernetes Security Monitor that periodically checks for common security issues in a cluster. It includes checks for privileged containers, missing network policies, and outdated Kubernetes versions. You can extend this project by adding more security checks, implementing alerting mechanisms, and integrating with external security tools.

To run this project, you would need to build it as a Docker image and deploy it within your Kubernetes cluster. Ensure that the service account associated with this pod has the necessary permissions to perform these checks.

package main

import (
    "context"
    "fmt"
    "log"
    "time"

    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/rest"
)

type SecurityMonitor struct {
    clientset *kubernetes.Clientset
}

func NewSecurityMonitor() (*SecurityMonitor, error) {
    // Create an in-cluster configuration
    config, err := rest.InClusterConfig()
    if err != nil {
        return nil, err
    }

    // Create the clientset
    clientset, err := kubernetes.NewForConfig(config)
    if err != nil {
        return nil, err
    }

    return &SecurityMonitor{clientset: clientset}, nil
}

func (sm *SecurityMonitor) RunChecks() {
    // Check for privileged containers
    sm.checkPrivilegedContainers()

    // Check for missing network policies
    sm.checkNetworkPolicies()

    // Check for outdated Kubernetes version
    sm.checkKubernetesVersion()
}

func (sm *SecurityMonitor) checkPrivilegedContainers() {
    pods, err := sm.clientset.CoreV1().Pods("").List(context.TODO(), metav1.ListOptions{})
    if err != nil {
        log.Printf("Error listing pods: %v", err)
        return
    }

    for _, pod := range pods.Items {
        for _, container := range pod.Spec.Containers {
            if container.SecurityContext != nil && container.SecurityContext.Privileged != nil && *container.SecurityContext.Privileged {
                log.Printf("Warning: Privileged container found in pod %s/%s", pod.Namespace, pod.Name)
            }
        }
    }
}

func (sm *SecurityMonitor) checkNetworkPolicies() {
    policies, err := sm.clientset.NetworkingV1().NetworkPolicies("").List(context.TODO(), metav1.ListOptions{})
    if err != nil {
        log.Printf("Error listing network policies: %v", err)
        return
    }

    if len(policies.Items) == 0 {
        log.Println("Warning: No network policies defined")
    }
}

func (sm *SecurityMonitor) checkKubernetesVersion() {
    info, err := sm.clientset.Discovery().RESTClient().Get().Namespace("").Resource("version").DoRaw(context.TODO())
    if err != nil {
        log.Printf("Error getting Kubernetes version: %v", err)
        return
    }

    // Implement logic to compare current version with latest stable version
    // For simplicity, we'll just log the current version
    log.Printf("Current Kubernetes version: %s", string(info))
}

func main() {
    monitor, err := NewSecurityMonitor()
    if err != nil {
        log.Fatalf("Failed to create security monitor: %v", err)
    }

    for {
        monitor.RunChecks()
        time.Sleep(60 * time.Minute) // Run checks every hour
    }
}