Praveen Kumar praveenkumar

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

I use these ansible scripts (see also) to bring up kubernetes clusters, on centos and fedora. The scripts are awesome, but they put selinux into permissive mode, because, "tokens and selinux don't work together."

That's unfortunate, because one of the main things I'm doing when I turn up a kubernetes cluster is bug-hunting, and selinux can be a source of bugs.

I commented out the bit that put selinux into permissive mode:

#- name: Set selinux permissive because tokens and selinux don't work together
#  selinux: state=permissive policy={{ ansible_selinux.type }}
# when: ansible_selinux is defined and ansible_selinux.status == "enabled"

See also, http://libraryofalexandria.io/cgo/

Using Go `cgo`

cgo has a lot of trap.
but Not "C" pkg also directory in $GOROOT/src. IDE's(vim) Goto command not works.

So, Here collect materials.

TL;DR

Create 5GB FreeBSD image.
Install FreeBSD on xhyve.
Mount host directory.

Requisites

progrium/bashstyle

Bash is the JavaScript of systems programming. Although in some cases it's better to use a systems language like C or Go, Bash is an ideal systems language for smaller POSIX-oriented or command line tasks. Here's three quick reasons why:

It's everywhere. Like JavaScript for the web, Bash is already there ready for systems programming.
It's neutral. Unlike Ruby, Python, JavaScript, or PHP, Bash offends equally across all communities. ;)
It's made to be glue. Write complex parts in C or Go (or whatever!), and glue them together with Bash.

This document is how I write Bash and how I'd like collaborators to write Bash with me in my open source projects. It's based on a lot of experience and time collecting best practices. Most of them come from these two articles, but here integrated, slightly modified, and focusing on the most bang for buck items. Plus some ne

	apiVersion: v1
	items:
	- apiVersion: v1
	kind: ImageStream
	metadata:
	annotations:
	openshift.io/image.dockerRepositoryCheck: 2017-06-28T15:00:23Z
	creationTimestamp: null
	generation: 2
	labels:

	package main

	import (
	"crypto/tls"
	"crypto/x509"
	"flag"
	"io"
	"io/ioutil"
	"log"
	"os"

	#!/boot/bzImage

	# Linux kernel userspace initialization code, translated to bash
	# (Minus floppy disk handling, because seriously, it's 2017.)
	# Not 100% accurate, but gives you a good idea of how kernel init works
	# GPLv2, Copyright 2017 Hector Martin <[email protected]>
	# Based on Linux 4.10-rc2.

	# Note: pretend chroot is a builtin and affects the current process
	# Note: kernel actually uses major/minor device numbers instead of device name

	/*

	Watch out, os.IsExist(err) != !os.IsNotExist(err)

	They are error checkers, so use them only when err != nil, and you want to handle
	specific errors in a different way!

	Their main purpose is to wrap around OS error messages for you, so you don't have to test
	for Windows/Unix/Mobile/other OS error messages for "file exists/directory exists" and
	"file does not exist/directory does not exist"

	#!/usr/bin/env ruby
	require 'rubydns'

	INTERFACES = [
	[:udp, "0.0.0.0", 53],
	[:tcp, "0.0.0.0", 53]
	]
	Name = Resolv::DNS::Name
	IN = Resolv::DNS::Resource::IN