Anthropic-Cybersecurity-Skills/skills/implementing-container-network-policies-with-calico/SKILL.md

name, description, domain, subdomain, tags, version, author, license

name	description	domain	subdomain	tags	version	author	license
implementing-container-network-policies-with-calico	Enforce Kubernetes network segmentation using Calico CNI network policies and global network policies to control pod-to-pod traffic, restrict egress, and implement zero-trust microsegmentation.	cybersecurity	container-security	container-security kubernetes calico network-policy microsegmentation cni	1.0	mahipal	MIT

Implementing Container Network Policies with Calico

Overview

Calico provides Kubernetes-native and extended network policy enforcement through its CNI plugin. This skill covers creating and auditing Calico NetworkPolicy and GlobalNetworkPolicy resources to implement pod-to-pod traffic control, namespace isolation, egress restrictions, and DNS-based policy rules using calicoctl and the Kubernetes API.

Prerequisites

• Kubernetes cluster with Calico CNI installed
• Python 3.9+ with kubernetes client library
• calicoctl CLI tool installed and configured
• kubectl access with RBAC permissions for network policy management

Steps

Step 1: Audit Existing Network Policies

Use calicoctl and kubectl to inventory current network policies and identify unprotected namespaces.

Step 2: Implement Default-Deny Policies

Create default-deny ingress and egress policies per namespace as a zero-trust baseline.

Step 3: Create Workload-Specific Allow Rules

Define granular allow rules for legitimate pod-to-pod and pod-to-service communication.

Step 4: Validate Policy Enforcement

Test connectivity between pods to verify policies are correctly enforced.

Expected Output

JSON audit report listing all network policies, unprotected namespaces, policy rule counts, and connectivity test results.