I’m pretty proud of this one as well. package sieve //Sieve Uses the Sieve of Eratosthenes to calculate primes to a certain limit func Sieve(limit int) []int { var listOfPrimes []int markers := make([]bool, limit) for i := 2; i < limit; i++ { if !markers[i] { for j := i + i; j < limit; j += i { markers[j] = true } listOfPrimes = append(listOfPrimes, i) } } return listOfPrimes }

If you are installing something with Packer and you have Headless enabled(and you are lazy and don’t want to switch it off), it gets difficult, to see output. Especially on a windows install the Answer File / Unattended install can be like => Waiting for SSH. for about an hour or two! If you are doing this locally fret not. Just start VirtualBox, and watch the Preview section which will display the current state even if it’s a headless install! ...

I quiet like this one. My first go program snippet without any peaking or googling. I’m proud, though it could be improved with a bit of struct magic and such and such. And it only counts ’till 1000. package main import "fmt" var words = map[int]string{1: "one", 2: "two", 3: "three", 4: "four", 5: "five", 6: "six", 7: "seven", 8: "eight", 9: "nine", 10: "ten", 11: "eleven", 12: "twelve", 13: "thirteen", 14: "fourteen", 15: "fifteen", 16: "sixteen", 17: "seventeen", 18: "eighteen", 19: "nineteen", 20: "twenty", 30: "thirty", 40: "forty", 50: "fifty", 60: "sixty", 70: "seventy", 80: "eighty", 90: "ninety"} // CountLetters count the letters in a long string number representation func CountLetters(limit int) { myLongNumberString := "" for i := 1; i <= limit; i++ { addLettersToMyString(&myLongNumberString, i) } // fmt.Println("1-9 written with letters is: ", len(myLongNumberString)) fmt.Println("The string is:", myLongNumberString) fmt.Println("Lenght of string is:", len(myLongNumberString)) } func addLettersToMyString(myString *string, num int) { if num < 20 { *myString += words[num] } if num >= 20 && num < 100 { *myString += countMiddle(num) } if num >= 100 && num < 1000 { hundred, tenth := countHundred(num) if tenth == { *myString += hundred } else if tenth >= 11 && tenth < 20 { *myString += hundred + "and" + words[tenth] } else { *myString += hundred + "and" + countMiddle(tenth) } } if num == 1000 { *myString += "onethousand" } } func countMiddle(num int) string { minues := num % 10 num -= minues return words[num] + words[minues] } func countHundred(num int) (string, int) { minues := num % 100 num -= minues return (words[(num/100)] + "hundred"), minues }

So, recently, the tester team talked to me, that their build takes too long, and why is that? A quick look at their configuration and build scripts showed me, that they are actually using a vagrant box, which never gets destroyed or re-started at least. To remedy this problem, I came up with the following solution. ...

The first, and only time so far, that I got to use the bitwise & operator. I enjoyed doing so!! And of course from now on, I’ll be looking for more opportunities to (ab)use it. package secret import "sort" const REVERSE = 16 func Handshake(code int) []string { // binary_rep := convertDecimalToBinary(code) if code < { return nil } secret_map := map[int]string { 1: "wink", 2: "double blink", 4: "close your eyes", 8: "jump", } var keys []int for k := range secret_map { keys = append(keys, k) } // To make sure iteration is always in the same order. sort.Ints(keys) code_array := make([]string, ) for _, key := range keys { if code & key == key { code_array = append(code_array, secret_map[key]) } } if code & REVERSE == REVERSE { code_array = reverse_array(code_array) } return code_array } func reverse_array (array_to_reverse []string) []string { for i, j := , len(array_to_reverse) -1 ; i < j; i, j = i + 1, j - 1 { array_to_reverse[i], array_to_reverse[j] = array_to_reverse[j], array_to_reverse[i] } return array_to_reverse }

Previously I wrote that the scripts I’m writing, are failing because Packer hangs. Apparently, this was a known issue. And apparently, I was using an older version, 0.7.5. After I updated everything is working wonderfully!!! And for my thanks, here is an updated PowerShell script for provisioning my dotnet stuff. $source = "http://download.microsoft.com/download/1/6/7/167F0D79-9317-48AE-AEDB-17120579F8E2/NDP451-KB2858728-x86-x64-AllOS-ENU.exe" $destination = "C:\Windows\Temp\dotnet.exe" Write-Host 'Starting to download dotnet file.' try { (New-Object System.Net.WebClient).DownloadFile($source, $destination) } catch [Exception] { Write-Host "Exception during download. Probable cause could be that the directory or the file didn't exist." Write-Host '$_.Exception is' $_.Exception } Write-Host 'Download done. Checking if file exists.' if (!(Test-Path $destination)) { Write-Host 'Downloading dotnet Failed!' } else { Write-Host 'Download successful.' } Write-Host 'Starting install process.' try { Start-Process -FilePath $source -ArgumentList "/q /norestart" -Wait -PassThru } catch [Exception] { Write-Host 'Exception during install process.' Write-Host '$_.Exception is' $_.Exception } Write-Host 'All done. Goodbye.' Thanks for reading! ...

Hello folks. Today, I would like to show you a small script. It installs Java JDK, both version, x86 and 64 bit, silently, and wait for that process to finish. The wait is necessary because /s on a java install has the nasty habit of running in the background. If you are using a .bat file, you shouldn’t, than you would use something like: start /w jdk-setup.exe /s. This gets it done, but is ugly. Also, if you are using Packer and PowerShell provisioning, you might want to set up some environment variables as well for the next script. And you want that property to be available and you don’t want to mess it up with setting a path into a file and then re-setting your path on the begin of your other script. Or pass it around with Packer. No. Use a proper PowerShell script. Learn it. It’s not that hard. Be a professional. Don’t hack something together for the next person to suffer at. ...

Hello folks. Today, I would like to write about something close to my heart recently. I’ve been fiddling with Packer, Windows and Vagrant these days. Trying to get a Windows box up in running is a pain in the arse though, so I thought I share my pain with you nice folks out there. Let’s begin. ...

Hello folks. Today, I would like to write about something interesting and close to me at the moment. I’m going to setup Go.cd with Docker, and I’m going to get a Ruby Lotus app running. Let’s get started. ...

Hello folks. So, some of you know puppet, some of you don’t. Puppet is a configuration management system. It’s quite awesome. I like working with it. One of the benefits of puppet is, that I never, ever, EVER have to setup a new laptop from scratch, EVER again. I’m writing a puppet manifest file which sets up my new laptop to my liking. I will improve it as I go along. Here is version 1.0. ...