feat: GQL Container.init.ps1 ( Fixes #11 )

Author: James Brundage

Container.init.ps1

@@ -0,0 +1,111 @@
+<#
+.SYNOPSIS
+    Initializes a container during build.
+.DESCRIPTION
+    Initializes the container image with the necessary modules and packages.
+
+    This script should be called from the Dockerfile, during the creation of the container image.
+
+    ~~~Dockerfile
+    # Thank you Microsoft!  Thank you PowerShell!  Thank you Docker!
+    FROM mcr.microsoft.com/powershell
+    # Set the shell to PowerShell (thanks again, Docker!)
+    SHELL ["/bin/pwsh", "-nologo", "-command"]
+    # Run the initialization script.  This will do all remaining initialization in a single layer.
+    RUN --mount=type=bind,src=./,target=/Initialize ./Initialize/Container.init.ps1
+    ~~~
+    
+    The scripts arguments can be provided with either an `ARG` or `ENV` instruction in the Dockerfile.
+.NOTES
+    Did you know that in PowerShell you can 'use' namespaces that do not really exist?
+    This seems like a nice way to describe a relationship to a container image.
+    That is why this file is using the namespace 'mcr.microsoft.com/powershell'.
+    (this does nothing, but most likely will be used in the future)
+#>
+using namespace 'mcr.microsoft.com/powershell AS powershell'
+
+param(
+# The name of the module to be installed.
+[string]$ModuleName = $(
+    if ($env:ModuleName) { $env:ModuleName }
+    else {
+        (Get-ChildItem -Path $PSScriptRoot |
+        Where-Object Extension -eq '.psd1' |
+        Select-String 'ModuleVersion\s=' |
+        Select-Object -ExpandProperty Path -First 1) -replace '\.psd1$'
+    }
+),
+# The packages to be installed.
+[string[]]$InstallAptGet = @($env:InstallAptGet -split ','),
+# The modules to be installed.
+[string[]]$InstallModule = @($env:InstallModule -split ','),
+# The Ruby gems to be installed.
+[string[]]$InstallRubyGem = @($env:InstallRubyGem -split ','),
+
+# If set, will keep the .git directories.
+[switch]$KeepGit = $($env:KeepGit -match $true)
+)
+
+# Copy all container-related scripts to the root of the container.
+Get-ChildItem -Path $PSScriptRoot | 
+    Where-Object Name -Match '^Container\..+?\.ps1$' | 
+    Copy-Item -Destination /
+
+# Create a profile
+New-Item -Path $Profile -ItemType File -Force | Out-Null
+
+if ($ModuleName) {
+    # Get the root module directory
+    $rootModuleDirectory = @($env:PSModulePath -split '[;:]')[0]
+
+    # Determine the path to the module destination. 
+    $moduleDestination = "$rootModuleDirectory/$ModuleName"
+    # Copy the module to the destination
+    # (this is being used instead of the COPY statement in Docker, to avoid additional layers).
+    Copy-Item -Path "$psScriptRoot" -Destination $moduleDestination -Recurse -Force
+
+    # and import this module in the profile
+    Add-Content -Path $profile -Value "Import-Module $ModuleName" -Force
+}
+
+# If we have modules to install
+if ($InstallModule) { 
+    # Install the modules
+    Install-Module -Name $InstallModule -Force -AcceptLicense -Scope CurrentUser
+    # and import them in the profile
+    Add-Content -Path $Profile -Value "Import-Module '$($InstallModule -join "','")'" -Force
+}
+
+# If we have packages to install
+if ($InstallAptGet) {
+    # install the packages
+    apt-get update && 
+        apt-get install -y @InstallAptGet '--no-install-recommends' && 
+            apt-get clean |
+                Out-Host
+}
+
+if ($InstallRubyGem) {
+    # Install the Ruby gems
+    gem install @InstallRubyGem
+}
+
+if ($ModuleName) {
+    # In our profile, push into the module's directory
+    Add-Content -Path $Profile -Value "Get-Module $ModuleName | Split-Path | Push-Location" -Force
+}
+
+if (-not $KeepGit) {
+    # Remove the .git directories from any modules
+    Get-ChildItem -Path $rootModuleDirectory -Directory -Force -Recurse |
+        Where-Object Name -eq '.git' |
+        Remove-Item -Recurse -Force
+}
+
+# Congratulations! You have successfully initialized the container image.
+# This script should work in about any module, with minor adjustments.
+# If you have any adjustments, please put them below here, in the `#region Custom`
+
+#region Custom
+
+#endregion Custom