# Implementing Container Network Policies With Calico

> Uses Calico's own policy CRDs beyond the upstream Kubernetes API - GlobalNetworkPolicy, HostEndpoint, NetworkSet, policy tiers, and DNS-based egress rules - applied and audited with calicoctl. Use when a policy must span namespaces or protect the host itself, when egress has to be expressed by domain name, or when ordering policies into tiers. Keywords: calicoctl, GlobalNetworkPolicy, HostEndpoint, NetworkSet, tier, DNS egress, order. Do not use for portable upstream NetworkPolicy - use implementing-network-policies-for-kubernetes; for installing Calico and writing standard policy with it use implementing-kubernetes-network-policy-with-calico.

- Skill: `gabrielmoreira/implementing-container-network-policies-with-calico` (Agent Skill, multi-file: 4 files)
- Install (CLI): `npx skillmds@latest add gabrielmoreira/implementing-container-network-policies-with-calico`
- Raw SKILL.md: https://api.skillmd.com/api/skills/gabrielmoreira/implementing-container-network-policies-with-calico/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- License: Apache-2.0
- Author: gabrielmoreira (https://skillmd.com/u/gabrielmoreira)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/gabrielmoreira/implementing-container-network-policies-with-calico

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# 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.


## When to Use

- When deploying or configuring implementing container network policies with calico capabilities in your environment
- When establishing security controls aligned to compliance requirements
- When building or improving security architecture for this domain
- When conducting security assessments that require this implementation

## 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.