PSDepend

PSDepend is a PowerShell dependency handler. Define your dependencies in a simple .psd1 file and let Invoke-PSDepend install them — similar to pip install -r requirements.txt or bundle install.

Installing

# PowerShell 7+ (recommended)
Install-PSResource PSDepend

# PowerShell 5.1
Install-Module PSDepend

# Manual
# Download and unblock the repository zip, then extract the PSDepend folder
# to a module path (e.g. $env:USERPROFILE\Documents\WindowsPowerShell\Modules\)

Quick Start

Import-Module PSDepend
Get-Command -Module PSDepend
Get-Help about_PSDepend

Defining Dependencies

Store dependencies in a PowerShell data file named *.depend.psd1 or requirements.psd1. Invoke-PSDepend will find these files automatically.

Simple syntax

@{
    psake        = 'latest'
    Pester       = 'latest'
    BuildHelpers = '0.0.20'
    PSDeploy     = '0.1.21'

    'PowerShellOrg/PSDepend' = 'master'
}

PSDepend infers PSGalleryModule for bare names and GitHub for owner/repo entries:

DependencyName          DependencyType  Version Tags
--------------          --------------  ------- ----
psake                   PSGalleryModule latest
BuildHelpers            PSGalleryModule 0.0.20
Pester                  PSGalleryModule latest
PowerShellOrg/PSDepend  GitHub          master
PSDeploy                PSGalleryModule 0.1.21

You can also specify the dependency type explicitly:

@{
    'PSGalleryModule::InvokeBuild'       = 'latest'
    'GitHub::PowerShellOrg/PSDepend'     = 'master'
}

Flexible syntax

For more control, use the hashtable syntax. You can mix and match styles within the same file:

@{
    psdeploy = 'latest'

    buildhelpers_0_0_20 = @{
        Name = 'buildhelpers'
        DependencyType = 'PSGalleryModule'
        Parameters = @{
            Repository = 'PSGallery'
            SkipPublisherCheck = $true
        }
        Version = '0.0.20'
        Tags = 'prod', 'test'
        PreScripts = 'C:\RunThisFirst.ps1'
        DependsOn = 'some_task'
    }

    some_task = @{
        DependencyType = 'task'
        Target = 'C:\RunThisFirst.ps1'
        DependsOn = 'nuget'
    }

    nuget = @{
        DependencyType = 'FileDownload'
        Source = 'https://dist.nuget.org/win-x86-commandline/latest/nuget.exe'
        Target = 'C:\nuget.exe'
    }
}

To inspect the full dependency output:

$Dependency = Get-Dependency \\Path\To\complex.depend.psd1
$Dependency[2] | Select-Object *

DependencyFile : \\Path\To\complex.depend.psd1
DependencyName : buildhelpers_0_0_20
DependencyType : PSGalleryModule
Name           : buildhelpers
Version        : 0.0.20
Parameters     : {Repository,SkipPublisherCheck}
Source         :
Target         :
AddToPath      :
Tags           : {prod, test}
DependsOn      : some_task
PreScripts     : C:\RunThisFirst.ps1
PostScripts    :
Raw            : {Version, Name, Tags, DependsOn...}

The following strings are expanded in Target and Source fields: $PWD (or .), $ENV:USERPROFILE, $ENV:TEMP, $ENV:ProgramData, $ENV:APPDATA. Use single quotes or escape the $ to prevent PowerShell from expanding them before PSDepend can: Target = '$PWD\dependencies'.

Repository Credentials

For private repositories that require authentication, set a Credential key in the dependency and pass a matching PSCredential object to Invoke-PSDepend:

@{
    buildhelpers_0_0_20 = @{
        Name = 'buildhelpers'
        DependencyType = 'PSGalleryModule'
        Parameters = @{
            Repository = 'MyPrivateGallery'
        }
        Version = '0.0.20'
        Credential = 'my_gallery'
    }
}

Invoke-PSDepend -Path C:\requirements.psd1 -Credentials @{ 'my_gallery' = $creds }

The credential key must match between the dependency definition and the hashtable passed to -Credentials.

Getting Help

Each dependency type may handle standard properties differently and expose its own parameters. Use Get-PSDependType to see what is available:

Get-PSDependType

DependencyType  Description                                                 DependencyScript
--------------  -----------                                                 ----------------
PSGalleryModule Install a PowerShell module from the PowerShell Gallery.    C:\...\PSDepend\PSDepen...
Task            Support dependencies by handling simple tasks.              C:\...\PSDepend\PSDepen...
Noop            Display parameters that a depends script would receive...   C:\...\PSDepend\PSDepen...
FileDownload    Download a file                                             C:\...\PSDepend\PSDepen...

Read the comment-based help for any dependency type:

Get-PSDependType -DependencyType PSGalleryModule -ShowHelp

Additional help topics:

Get-Help about_PSDepend
Get-Help about_PSDepend_Definitions
Get-Help Get-Dependency -Full

Extending PSDepend

PSDepend is extensible. To add a new dependency type, create a script in the PSDependScripts folder and register it in PSDependMap.psd1.

Your script must:

• Include comment-based help describing how it uses Dependency metadata
• Accept a PSDependAction parameter with values Install, Test, and/or Import
• Implement the expected behavior for each action (Install installs, Test returns a boolean, Import loads the dependency)

See Git.ps1 and PSGalleryModule.ps1 for reference implementations.

Examples

• Creating a virtual environment
• Handling module dependencies
• How Do I...

Contributing

Contributions are welcome. Please read the PowerShellOrg contributing guide before opening a pull request.

Acknowledgements

PSDepend was originally created by Warren Frame (RamblingCookieMonster) and is now maintained by the PowerShellOrg organization.

The concept was inspired by Michael Willis's PSRequire.