Norman Khine nkhine

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

Create a dedicated ZFS docker pool with deduplication disabled in case of dedup enabled on your system:

zfs create -o mountpoint=/var/lib/docker -o dedup=off rpool/docker

Sometimes, you don't want ZFS for docker storage. ZFS can be sadly quite painful with Docker in Docker and similar scenarios. It might be best to avoid the problem by creating a volume in your ZFS pool, formatting that volume to ext4, and having docker use "overlay2" on top of that, instead of "zfs".

zfs create -s -V 30G rpool/docker

mkfs.ext4 /dev/zvol/rpool/docker

Kubectl output options

Let's look at some basic kubectl output options.

Our intention is to list nodes (with their AWS InstanceId) and Pods (sorted by node).

We can start with:

kubectl get no

jobs

jenkins_url + /api/json?tree=jobs[name,color]

builds

jenkins_url + /job/${job_name}/api/json?tree=builds[number,status,timestamp,id,result]

last build

AWS CLI Cheatsheet

http://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html https://www.youtube.com/watch?v=_wiGpBQGCjU

Setup

$ sudo -i
# vim /etc/systemd/system/disable-transparent-huge-pages.service
# systemctl enable disable-transparent-huge-pages
# systemctl start disable-transparent-huge-pages
# systemctl status disable-transparent-huge-pages
# cat /sys/kernel/mm/transparent_hugepage/enabled
# cat /sys/kernel/mm/transparent_hugepage/defrag

	<#
	- BIOS of host machine also needs to be configured to allow hardware virtualization
	- This gist WSLv2, but can use WSLv1 instead. I needed v1 as I run Windows 10 in a VM in Virtualbox.
	- WSLv2 has been giving me problems in Virtualbox 6.1, but WSLv1 works properly.
	- vbox has issues with the GUI settings when it comes to nested virtualization on certain systems,
	so run the following if needing to give a VM this enabled setting:

	VBoxManage modifyvm <vm-name> --nested-hw-virt on
	#>

	#! /bin/sh
	### BEGIN INIT INFO
	# Provides: vpnclient
	# Required-Start: $all
	# Required-Stop: $network $local_fs $remote_fs $syslog
	# Default-Start: 2 3 4 5
	# Default-Stop: 0 1 6
	# Short-Description: Start VPN Client at boot time
	# chkconfig: 345 44 56
	# description: Start VPN Client at boot time.

	### No longer needed as of nginx-1.13.9-1.el7_4.ngx.x86_64.rpm from nginx.org
	### it was compiled against OpenSSL 1.0.2 from CentoOS 7.4 so it supports ALPN (HTTP2 works)
	### nginx-module-njs-1.13.9.0.1.15-1.el7_4.ngx.x86_64.rpm

	yum -y groupinstall 'Development Tools'
	yum -y install wget openssl-devel libxml2-devel libxslt-devel gd-devel perl-ExtUtils-Embed GeoIP-devel rpmdevtools

	OPENSSL="openssl-1.0.2l"
	NGINX_VERSION="1.13.9-1"
	NJS_VERSION="1.13.9.0.1.15-1"

	AWSTemplateFormatVersion: '2010-09-09'
	Description: Cognito Stack
	Parameters:
	AuthName:
	Type: String
	Description: Unique Auth Name for Cognito Resources

	Resources:

	# Creates a role that allows Cognito to send SNS messages