Michael Weiner mike-weiner

Basic Linux Server Hardening

This document is meant to serve as a basic guide for hardening a Linux server.

Change Default Port Used by SSH

sudo nano /etc/ssh/sshd_config
Uncomment #Port 22 and change it to Port <SSH_PORT>. (Replace <SSH_PORT> with your desired port to use for SSH connectivity.)
sudo systemctl restart ssh
reboot

Helpful `kubectl` Commands

This Markdown file is a collection of helpful kubectl commands that I repeadetly finding myself using.

Pods

Print the name of every container in a pod on a newline: kubectl get pod -n <namespace> <podname> -o jsonpath='{range .spec.containers[*]}{.name}{"\n"}{end}'
Print the name of every container (and its image) found inside of a pod: kubectl get pod -n -o jsonpath='{range .spec.containers[*]}{.name}{" | "}{.image}{"\n"}{end}

Install Previous Homebrew Formula

Sometimes you need to install a specific, older version of an existing Homebrew Formula. In this guide I am going to demonstrate how to install an older version of kubectl, but it can be generalized for an Formula.

The Kubernetes CLI is available as a Homebrew Formulae: https://formulae.brew.sh/formula/kubernetes-cli#default

At the time of writing, my only options to install kubectl via Homebrew are:

brew install kubectl
- Would install the default version of v1.29
brew install [email protected] or brew install [email protected]

	package main

	import (
	"context"
	"fmt"
	"net"
	"time"
	)

	func main() {

	#!/bin/bash

	SLACK_CHANNEL="automation"
	SLACK_URL="https://slack.com/api/chat.postMessage"
	AS_USER=true

	slackMsgHeaderBlock=$(
	jq -n '{
	type: "rich_text",
	elements: [

	# Useage:
	# 1. Build Image: docker build -t network-debug -f Dockerfile.network-debug .
	# 1a. Ensure Image is Built: docker images
	# 2. Create Container from Image: docker run -d network-debug
	# 3. Exec into Container: docker exe -it <containerID> bash
	# 4. Stop Container After Usage: docker stop <containerID>

	FROM alpine:latest

	RUN apk upgrade --allow-untrusted && \

	# This YAML describes a rudimentary echoserver DaemonSet
	# that can be useful for debugging purposes, especially
	# when it comes to Services.

	apiVersion: apps/v1
	kind: DaemonSet
	metadata:
	name: echoserver-debug
	namespace: default
	labels:

	import json
	import requests

	# API v2 Base URL
	BASE_URL = "https://api.weatherlink.com/v2/"

	# Your WeatherLink Account API Credentials
	API_KEY = "<your-api-key>"
	API_SECRET = "<your-api-secret>"

	curl \
	-H "X-Api-Secret: <your-weatherlink-api-secret>" \
	'https://api.weatherlink.com/v2/stations?api-key=<your-weatherlink-api-key>'