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Using Dnsmasq with Ubuntu for VM web application testing

When running virtual machines under a Linux host system for testing web apps in various browsers (e.g. Internet Explorer), I found it rather tedious having to continually tweak the hosts file within each VM for the purpose of adding entries pointing back to the host machine's development web server address.

Instead the steps below will setup Dnsmasq on a Ubuntu 16.04LTS, 14.04LTS or 12.04LTS host machine for the purpose of serving both it's own DNS queries and that of virtual machine guests. Dnsmasq will parse the /etc/hosts file on your host machine where we will keep a single set of DNS entires to our test web application(s).

• Method 1
  • Ubuntu 16.04LTS / 14.04LTS
  • Ubuntu 12.04LTS
• Method 2
  • Stop NetworkManager running it's own Dnsmasq

dodyg

#Intro

Kotlin is a new programming language for the JVM. It produces Java bytecode, supports Android and generates JavaScript. The latest version of the language is Kotlin M5.3

Kotlin project website is at kotlin.jetbrains.org.

All the codes here can be copied and run on Kotlin online editor.

Let's get started.

dodyg

This is a quick guide to Kotlin programming language. The previous part of this guide is here

#Object Oriented

fun main(args : Array<String>) {
  class local (val x : Int)
  
  val y = local(10)
 println("${y.x}")

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD