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Overview

The goal of this document to cover all aspects of Kubernetes management, including how resources are expressed, constrained and accounted for. This started a way to ensure that alternate container runtime implementation like Kata containers will behave from a resource accounting and consumption point of view in the same manner as runc.

Location of the latest version of this document: https://gist.github.com/mcastelino/b8ce9a70b00ee56036dadd70ded53e9f

If you do not understand cgroups please refer to a quick primer at the bottom of this document. This will help you understand how the resource enforcement actually works.

Kubernetes Resource Management

Prepare files and directories

mkdir -p fluentdCA/{private,newcerts,certs,crl}
touch fluentdCA/index.txt
echo 00 > fluentdCA/serial

Setup private CA

Installing h2load on Your Dev Machine

Included are the steps for macOS and Ubuntu/Debian. I didn't do Windows because I don't have or use Windows. 😕

Revert the full commit

Sometimes you may want to undo a whole commit with all changes. Instead of going through all the changes manually, you can simply tell git to revert a commit, which does not even have to be the last one. Reverting a commit means to create a new commit that undoes all changes that were made in the bad commit. Just like above, the bad commit remains there, but it no longer affects the the current master and any future commits on top of it.

git revert {commit_id}

About History Rewriting

Delete the last commit

Deleting the last commit is the easiest case. Let's say we have a remote origin with branch master that currently points to commit dd61ab32. We want to remove the top commit. Translated to git terminology, we want to force the master branch of the origin remote repository to the parent of dd61ab32:

shadowsocks + privoxy/tsocks

shadowsocks: service, socks proxy
privoxy: service, convert socks proxy to http proxy
tsocks: tool, use socks proxy for any command line

Usage

tested under ubuntu14.04

HTTP Streaming (or Chunked vs Store & Forward)

The standard way of understanding the HTTP protocol is via the request reply pattern. Each HTTP transaction consists of a finitely bounded HTTP request and a finitely bounded HTTP response.

However it's also possible for both parts of an HTTP 1.1 transaction to stream their possibly infinitely bounded data. The advantages is that the sender can send data that is beyond the sender's memory limit, and the receiver can act on

	import logging
	from colorama import init, Fore, Back

	init(autoreset=True)


	class ColorFormatter(logging.Formatter):
	# Change this dictionary to suit your coloring needs!
	COLORS = {
	"WARNING": Fore.RED,

	#### WAY with crictl
	#### TODO validate crictl with docker runtime !!

	# Get all pods of a specific node
	#kubectl get po --field-selector=spec.nodeName="fluffy-master" --all-namespaces
	kubectl get --all-namespaces po --field-selector=spec.nodeName=="$(hostname)" -o json \| jq -r '.items[] \| select(.status.hostIP!=.status.podIP) \| "\(.metadata.name) \(.metadata.namespace)"'

	# Get the Pod ID of the Pod with crictl
	POD_ID=$(sudo crictl pods --name=nginx-6f858d4d45-vnszm --namespace=default -q --no-trunc)

	# UPDATED 17 February 2019
	# Redirect all HTTP traffic to HTTPS
	server {
	listen 80;
	listen [::]:80;
	server_name www.domain.com domain.com;
	return 301 https://$host$request_uri;
	}

	# SSL configuration

	URL="http://stackoverflow.com/"

	# store the whole response with the status at the and
	HTTP_RESPONSE=$(curl --silent --write-out "HTTPSTATUS:%{http_code}" -X POST $URL)

	# extract the body
	HTTP_BODY=$(echo $HTTP_RESPONSE \| sed -e 's/HTTPSTATUS\:.*//g')

	# extract the status
	HTTP_STATUS=$(echo $HTTP_RESPONSE \| tr -d '\n' \| sed -e 's/.*HTTPSTATUS://')