Powershell scripting 08-Dec-19

Windows-Features

• Windows Features add inbuilt optional functionality to Windows Servers/Desktops

• From Powershell you can do the same thing by using a cmdlet

  • Windows10 – Enable-WindowsOptionalFeature
  • Windows Server – Install-WindowsFeature

• Lets Execute the following command

Get-Command *-WindowsOptionalFeature
Get-Help Get-WindowsOptionalFeature -Online
Get-WindowsOptionalFeature -Online | More

• Lets Install IIS Server on Windows 10 Clients

Enable-WindowsOptionalFeature -Online -FeatureName IIS-Webserver -All

• Write a Powershell script which displays all the features available for installation and Asks for user input to install a windows feature. Script name is InstallFeature.PS1

InstallFeature.ps1
0 -> <featurename>
1 -> <featurename>
..
...

Enter the number of the feature which you want to install?

• Solution is

$disabledFeatures = Get-WindowsOptionalFeature -Online | where State -NE 'Enabled'| Select FeatureName
for ($index = 0; $index -lt $disabledFeatures.Length; $index++) {
    $currentFeature = $disabledFeatures[$index]
    Write-Output "$index  => $currentFeature"
}
$choice = Read-Host -Prompt "Enter Your Choice"
$choiceinint = [convert]::ToInt32($choice)
Enable-WindowsOptionalFeature -Online -FeatureName $disabledFeatures[$choiceinint]

• Write a script to uninstall the installed features

$installedfeatures = Get-WindowsOptionalFeature -Online | where State -EQ 'Enabled' | Select FeatureName

for ($index = 0; $index -lt $installedfeatures.Count; $index++) {
    $currentFeature = $installedfeatures[$index]
    Write-Output "$index  => $currentFeature"
}

$choice = Read-Host -Prompt "Enter the choice for uninstall. If you want to quit enter y"

if ($choice -ne 'y') {
    $choiceinint = [convert]::ToInt32($choice)
    Disable-WindowsOptionalFeature -FeatureName $installedfeatures[$choiceinint]
}

Powershell Modules

• Modules are collection of cmd-lets and other powershell utilities
• Experimenting:
  • Install a module for chocolatey installations and Write a script in powershell to search chocolatey for available softwares.
  • Install any module from powershell gallery

  Install-Module -Name chocolatey
  Get-Command -Module chocolatey
  

• Exercise -1 : Use Chocolatey module to install tools required for devops

$mandatorytools = ('git', 'vscode')
$optionaltools = ('chefdk', 'packer', 'terraform')

foreach ($tool in $mandatorytools) {
    Write-Output 'Installing $tool'
    Install-ChocolateyPackage -Name $tool -AcceptLicense
    
}

foreach ($tool in $optionaltools){
    $choice = Read-Host -Prompt "Do you want to install $tool. Enter y to install, any other key to skip"
    
    if ($choice -eq 'y') {
        Write-Output "Installing $tool"
        Install-ChocolateyPackage -Name $tool -AcceptLicense
    }
}

• Exercise-2: Write a Powershell script without using modules to install tools required for devops

$mandatorytools = ('git', 'vscode')
$optionaltools = ('chefdk', 'packer', 'terraform', 'winmerge')

foreach ($tool in $mandatorytools) {
    Write-Output "Installing $tool"
    Start-Process -NoNewWindow -FilePath 'choco.exe' -ArgumentList "install $tool -y"
}

foreach ($tool in $optionaltools){
    $choice = Read-Host -Prompt "Do you want to install $tool. Enter y to install, any other key to skip"
    
    if ($choice -eq 'y') {
        Write-Output "Installing $tool"
        Start-Process -NoNewWindow -FilePath 'choco.exe' -ArgumentList "install $tool -y"
    }
}

• Write a powershell script called installchocopackages.ps1 where the user executes the installtion by using the following command

./installchocopackages.ps1 -packagenames "git,vscode"
or
use string[] in the parameter and try the script.