Michael Weiner mike-weiner

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 kubectl@1.29 or brew install kubectl@1.28

	# 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 "Content-Type: application/json" \
	-d '{"content":"Your bot's message for the Discord channel goes here!"}' \
	<your-discord-webhook-url>

	#!/bin/bash

	# Function that will print requirements if the user passes in the -help flag as the first argument.
	function help
	{
	echo "Parameters are: "
	echo " <filename>: The full filename of the video that you want to crop."
	}

	# Check for '-help' flag.

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

	# Modifies the Command Line Prompt to the following format:
	# <Username> <Current Directory Name> <Current Git Branch Name (if applicable)> %

	# Load version control information
	autoload -Uz vcs_info
	precmd() { vcs_info }

	# Format the vcs_info_msg_0_ variable
	zstyle ':vcs_info:*' enable git
	zstyle ':vcs_info:*' formats '(%b)'

Michael Weiner mike-weiner

Helpful kubectl Commands

Pods

Install Previous Homebrew Formula

Helpful `kubectl` Commands