Packer DSC Provisioner

A Desired State Configuration provisioner for Packer.io, the machine image automation tool, allowing you to automate the generation of your Windows machine images in a repeatable, reliable way.

Works nicely when combined with a Vagrant development workflow, possibly leveraging the Vagrant DSC plugin.

Features:

• Automatically run DSC on a remote machine, from local DSC Configurations.
• Automatically configure PowerShell Package Management (specify install_package_management as true)
• Install DSC Resources from local or remote sources, including the PowerShell Gallery (see resource_paths and install_modules)
• Ability to use pre-generated MOF files, if required

Getting Started

The plugin can be used by downloading the pre-built binary, or by building the project locally and ensuring the binary is installed in the correct location.

On Mac OSX using Homebrew

If you are using Homebrew you can follow these steps to install the plugins:

brew install https://raw.githubusercontent.com/mefellows/packer-dsc/master/scripts/packer-provisioner-dsc.rb

Using pre-built binaries

1. Install Packer
2. Download the latest release for your host environment
3. Unzip the plugin binaries to a location where Packer will detect them at run-time, such as any of the following:

• The directory where the packer binary is.
• ~/.packer.d/plugins on Unix systems or %APPDATA%/packer.d/plugins on Windows.
• The current working directory.

1. Change to a directory where you have packer templates, and run as usual.

Using a local build

With Go 1.2+ installed, follow these steps to use these community plugins for Windows:

1. Install packer
2. Clone this repo
3. Run make dev
4. Copy the plugin binaries located in ./bin to a location where Packer will detect them at run-time, such as any of the following:

• The directory where the packer binary is. If you've built Packer locally, then Packer and the new plugins are already in $GOPATH/bin together.
• ~/.packer.d/plugins on Unix systems or %APPDATA%/packer.d/plugins on Windows.
• The current working directory.

1. Change to a directory where you have packer templates, and run as usual.

Introduction

Type: dsc

DSC Packer provisioner configures DSC to run on the machines by Packer from local modules and manifest files. Modules and manifests can be uploaded from your local machine to the remote machine.

-> Note: DSC will not be installed automatically by this provisioner. This provisioner expects that DSC is already installed on the machine. It is common practice to use the powershell provisioner before the DSC provisioner to install WMF4.0+, any required DSC Resources or connection to a DSC Pull server.

Basic Example

The example below is fully functional and expects the configured manifest file to exist relative to your working directory:

{
  "type": "dsc",
  "manifest_file": "manifests/Beanstalk.ps1",
  "configuration_file": "manifests/BeanstalkConfig.psd1",
  "configuration_params": {
    "-WebAppPath": "c:\\tmp",
    "-MachineName": "localhost"
  }
}

Configuration Reference

The reference of available configuration options is listed below.

Required parameters:

• manifest_file (string) - The main DSC manifest file to apply to kick off the entire thing.

Optional parameters:

• configuration_name (string) - The name of the Configuration module. Defaults to the base name of the manifest_file. e.g. Default.ps1 would result in Default.

• mof_path (string) - Relative path to a folder, containing the pre-generated MOF file.

• configuration_file (string) - Relative path to the DSC Configuration Data file. Configuration data is used to parameterise the configuration_file.

• configuration_params (object of key/value strings) - Set of Parameters to pass to the DSC Configuration.

• module_paths (array of strings) - Set of relative module paths. These paths are added to the DSC Configuration running environment to enable local modules to be addressed.

• resource_paths (array of strings) - Set of DSC Resources to upload for system-wide use. These paths are uploaded into ${env:programfiles}\WindowsPowershell\Modules to be used system-wide, unlike module_paths which is scoped to the current Configuration.

• install_modules (array of strings) - Set of PowerShell modules to be installed with the Install-Module command. See install_package_management if you would like the DSC Provisioner to install this command for you.

• install_package_management (bool) - Automatically installs the Package Management package manager (formerly OneGet) on the server.

• staging_dir (string) - The directory where files will be uploaded. Packer requires write permissions in this directory.

• clean_staging_dir (bool) - If true, staging directory is removed after executing DSC.

• working_dir (string) - The directory from which the command will be executed. Packer requires the directory to exist when running DSC.

• ignore_exit_codes (boolean) - If true, Packer will never consider the DSC provisioning process a failure.

• execute_command (string) - The command used to execute DSC. This has various configuration template variables available. See below for more information.

Execute Command

By default, Packer uses the following command to execute DSC:

{{if ne .ModulePath ""}}
$absoluteModulePaths = [string]::Join(";", ("{{.ModulePath}}".Split(";") | ForEach-Object { $_ | Resolve-Path }))
echo "Adding to path: $absoluteModulePaths"
$env:PSModulePath="$absoluteModulePaths;${env:PSModulePath}"
("{{.ModulePath}}".Split(";") | ForEach-Object { gci -Recurse  $_ | ForEach-Object { Unblock-File  $_.FullName} })
{{end}}

$script = $("{{.ManifestFile}}" | Resolve-Path)
echo "PSModulePath Configured: ${env:PSModulePath}"
echo "Running Configuration file: ${script}"

{{if eq .MofPath ""}}
# Generate the MOF file, only if a MOF path not already provided.
# Import the Manifest
. $script

cd "{{.WorkingDir}}"
$StagingPath = $(Join-Path "{{.WorkingDir}}" "staging")
{{if ne .ConfigurationFilePath ""}}
$Config = $(iex (Get-Content ("{{.WorkingDir}}" "{{.ConfigurationFilePath}}" | Resolve-Path) | Out-String))
{{end}}
{{.ConfigurationName}} -OutputPath $StagingPath {{.ConfigurationParams}}{{if ne .ConfigurationFilePath ""}} -ConfigurationData $Config{{end}}
{{else}}
$StagingPath = "{{.MofPath}}"
{{end}}

# Start a DSC Configuration run
Start-DscConfiguration -Force -Wait -Verbose -Path $StagingPath`

This command can be customized using the execute_command configuration. As you can see from the default value above, the value of this configuration can contain various template variables, defined below:

• WorkingDir - The path from which DSC will be executed.
• ConfigurationParams - Arguments to the DSC Configuration in k/v pairs.
• ConfigurationFilePath - The path to a DSC Configuration File, if any.
• ConfigurationName - The name of the DSC Configuration to run.
• ManifestFile - The path on the remote machine to the manifest file for DSC to use.
• ModulePath - The path to a directory on the remote machine containing the manifest files.
• MofPath - The path to a directory containing any existing MOF file(s) to use.

Examples

See the Examples directory.