Alberto Cavalcante albertocavalcante

Understanding Calico Selectors in Kubernetes

In Kubernetes, managing network policies is essential for controlling communication between pods. Calico is a popular open-source tool that offers a powerful and flexible way to create network policies, using selectors to define exactly what traffic is allowed or denied. This blog post will explain how these selectors work, using easy-to-understand examples.

Selector Basics

A Calico selector is like a set of rules that define what kind of pods are matched. Think of it like picking out toys from a toy box based on specific features like color, shape, or size.

	#!/bin/bash
	set -e

	# Versions can be overridden with environment variables
	BAZELISK_VERSION="${BAZELISK_VERSION:-v1.10.1}"
	BUILDIFIER_VERSION="${BUILDIFIER_VERSION:-v6.0.1}"

	LOCAL_BIN="/usr/local/bin"

	if [ "$(id -u)" -ne 0 ]; then

	#!/usr/bin/env python3
	# /// script
	# requires-python = ">=3.7"
	# ///

	"""
	DevContainer Documentation Generator

	This script generates README files for DevContainer features and templates.

	import requests
	import zipfile
	import os
	from io import BytesIO

	def fetch_and_extract_zip(url, extract_to='.'):
	# Configure the proxy if needed
	proxies = {
	'http': 'http://your_proxy:your_proxy_port',
	'https': 'http://your_proxy:your_proxy_port'

	from openai import OpenAI
	from typing import Final
	from pprint import pprint


	class GPTHelper:
	llm = OpenAI()

	REVERSE_WORD_SYSTEM_PROMPT: Final = """
	Given a word by the user, you must reverse it and display back.

	package main

	import "fmt"

	func main() {
	var a int
	var b *int

	a = 50
	b = &a

Alberto Cavalcante albertocavalcante

Understanding Calico Selectors in Kubernetes

Selector Basics

Equality