Uploading artifacts into Nexus via PowerShell

It may not be the most common thing, however it may happen that you would need to upload an artifact to a maven repository in Nexus via PowerShell. In order to achieve that, we will use Nexus REST API which for this task requires a multipart/form-data POST to /service/local/artifact/maven/content resource. This is however not a trivial task. It is notoriously difficult to manage a Multipart/form-data standard in PowerShell, as I already described in one of my previous post PowerShell tips and tricks – Multipart/form-data requests. As you can see this type of call is necessary in order to upload an artifact to your Nexus server. I will not get in a details about Multipart/form-data requests and if interested about the details, you can check just mentioned post.

For this purpose I created two cmdlets that will allow me to upload an artifact by supplying GAV parameters or by passing the GAV definition in a POM file. A couple of simple functions do support both of these cmdlets.

GAV definition in a POM file

As the heading suggests, this cmdlet will let you upload your artifact and specify the GAV parameters via a POM file.

function Import-ArtifactPOM()
{
	[CmdletBinding()]
	param
	(
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$EndpointUrl,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Repository,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$PomFilePath,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$PackagePath,
		[System.Management.Automation.PSCredential][parameter(Mandatory = $true)]$Credential
	)
	BEGIN
	{
		if (-not (Test-Path $PackagePath))
		{
			$errorMessage = ("Package file {0} missing or unable to read." -f $PackagePath)
			$exception =  New-Object System.Exception $errorMessage
			$errorRecord = New-Object System.Management.Automation.ErrorRecord $exception, 'ArtifactUpload', ([System.Management.Automation.ErrorCategory]::InvalidArgument), $PackagePath
			$PSCmdlet.ThrowTerminatingError($errorRecord)
		}
		
		if (-not (Test-Path $PomFilePath))
		{
			$errorMessage = ("POM file {0} missing or unable to read." -f $PomFilePath)
			$exception =  New-Object System.Exception $errorMessage
			$errorRecord = New-Object System.Management.Automation.ErrorRecord $exception, 'ArtifactUpload', ([System.Management.Automation.ErrorCategory]::InvalidArgument), $PomFilePath
			$PSCmdlet.ThrowTerminatingError($errorRecord)
		}

		Add-Type -AssemblyName System.Net.Http
	}
	PROCESS
	{
		$repoContent = CreateStringContent "r" $Repository
		$groupContent = CreateStringContent "hasPom" "true"
		$pomContent = CreateStringContent "file" "$(Get-Content $PomFilePath)" ([system.IO.Path]::GetFileName($PomFilePath)) "text/xml"
		$streamContent = CreateStreamContent $PackagePath

		$content = New-Object -TypeName System.Net.Http.MultipartFormDataContent
		$content.Add($repoContent)
		$content.Add($groupContent)
		$content.Add($pomContent)
		$content.Add($streamContent)

		$httpClientHandler = GetHttpClientHandler $Credential

		return PostArtifact $EndpointUrl $httpClientHandler $content
	}
	END { }
}

In order to invoke this cmdlet you will need to supply the following parameters:

  • EndpointUrl – Address of your Nexus server
  • Repository – Name of your repository in Nexus
  • PomFilePath – Full, literal path pointing to your POM file
  • PackagePath – Full, literal path pointing to your Artifact
  • Credential – Credentials in the form of PSCredential object

I will create a POM file with the following content:

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.mycompany.app</groupId>
  <artifactId>my-app</artifactId>
  <version>3</version>
</project>

And invoke my cmdlet in the following way:

$server = "http://nexus.maio.com"
$repoName = "maven"
$pomFile = "C:\Users\majcicam\Desktop\pom.xml"
$package = "C:\Users\majcicam\Desktop\junit-4.12.jar"
$credential = Get-Credential

Import-ArtifactPOM $server $repoName $pomFile $package $credential

If everything is correctly setup, you will be first asked to provide the credentials, then the upload will start. If it succeeds, you will receive back a string like this:

{"groupId":"com.mycompany.app","artifactId":"my-app","version":"3","packaging":"jar"}

It is a json representation of the information about imported package.

Manually supplying GAV parameters

The other cmdlet is based on a similar principle, however it doesn’t require a POM file to be passed in, instead it let you provide GAV values as parameter to the call.

function Import-ArtifactGAV()
{
	[CmdletBinding()]
	param
	(
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$EndpointUrl,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Repository,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Group,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Artifact,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Version,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Packaging,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$PackagePath,
		[System.Management.Automation.PSCredential][parameter(Mandatory = $true)]$Credential
	)
	BEGIN
	{
		if (-not (Test-Path $PackagePath))
		{
			$errorMessage = ("Package file {0} missing or unable to read." -f $packagePath)
			$exception =  New-Object System.Exception $errorMessage
			$errorRecord = New-Object System.Management.Automation.ErrorRecord $exception, 'XLDPkgUpload', ([System.Management.Automation.ErrorCategory]::InvalidArgument), $packagePath
			$PSCmdlet.ThrowTerminatingError($errorRecord)
		}

		Add-Type -AssemblyName System.Net.Http
	}
	PROCESS
	{
		$repoContent = CreateStringContent "r" $Repository
		$groupContent = CreateStringContent "g" $Group
		$artifactContent = CreateStringContent "a" $Artifact
		$versionContent = CreateStringContent "v" $Version
		$packagingContent = CreateStringContent "p" $Packaging
		$streamContent = CreateStreamContent $PackagePath

		$content = New-Object -TypeName System.Net.Http.MultipartFormDataContent
		$content.Add($repoContent)
		$content.Add($groupContent)
		$content.Add($artifactContent)
		$content.Add($versionContent)
		$content.Add($packagingContent)
		$content.Add($streamContent)

		$httpClientHandler = GetHttpClientHandler $Credential

		return PostArtifact $EndpointUrl $httpClientHandler $content
	}
	END { }
}

In order to invoke this cmdlet you will need to supply the following parameters:

  • EndpointUrl – Address of your Nexus server
  • Repository – Name of your repository in Nexus
  • Group – Group Id
  • Artifact – Maven artifact Id
  • Version – Artifact version
  • Packaging – Packaging type (at ex. jar, war, ear, rar, etc.)
  • PackagePath – Full, literal path pointing to your Artifact
  • Credential – Credentials in the form of PSCredential object

An example of invocation:

$server = "http://nexus.maio.com"
$repoName = "maven"
$group = "com.test"
$artifact = "project"
$version = "2.4"
$packaging = "jar"
$package = "C:\Users\majcicam\Desktop\junit-4.12.jar"
$credential = Get-Credential

Import-ArtifactGAV $server $repoName $group $artifact $version $packaging $package $credential

If all goes as expected you will again receive a response confirming the imported values.

{"groupId":"com.test","artifactId":"project","version":"2.4","packaging":"jar"}

Supporting functions

As you could see, my cmdlets relay on a couple of functions. They are essential in this process so I will analyse them one by one.

function CreateStringContent()
{
	param
	(
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Name,
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$Value,
		[string]$FileName,
		[string]$MediaTypeHeaderValue
	)
		$contentDispositionHeaderValue = New-Object -TypeName  System.Net.Http.Headers.ContentDispositionHeaderValue -ArgumentList @("form-data")
		$contentDispositionHeaderValue.Name = $Name

		if ($FileName)
		{
			$contentDispositionHeaderValue.FileName = $FileName
		}
		
		$content = New-Object -TypeName System.Net.Http.StringContent -ArgumentList @($Value)
		$content.Headers.ContentDisposition = $contentDispositionHeaderValue

		if ($MediaTypeHeaderValue)
		{
			$content.Headers.ContentType = New-Object -TypeName System.Net.Http.Headers.MediaTypeHeaderValue $MediaTypeHeaderValue
		}

		return $content
}

function CreateStreamContent()
{
	param
	(
		[string][parameter(Mandatory = $true)][ValidateNotNullOrEmpty()]$PackagePath
	)
		$packageFileStream = New-Object -TypeName System.IO.FileStream -ArgumentList @($PackagePath, [System.IO.FileMode]::Open)
		
		$contentDispositionHeaderValue = New-Object -TypeName  System.Net.Http.Headers.ContentDispositionHeaderValue "form-data"
		$contentDispositionHeaderValue.Name = "file"
		$contentDispositionHeaderValue.FileName = Split-Path $packagePath -leaf

		$streamContent = New-Object -TypeName System.Net.Http.StreamContent $packageFileStream
		$streamContent.Headers.ContentDisposition = $contentDispositionHeaderValue
		$streamContent.Headers.ContentType = New-Object -TypeName System.Net.Http.Headers.MediaTypeHeaderValue "application/octet-stream"

		return $streamContent
}

First two functions are there to create a correct HTTP content. Each content object we create will correspond to a content-disposition header. The first function will return a string type values for the just mentioned header, meanwhile the Stream content will return a stream that will be consumed later on, having as a value octet-stream representation of our artifact.

GetHttpClientHandler function is a helper that will create the right http client handler that contains the credentials to be used for our call.

function GetHttpClientHandler()
{
	param
	(
		[System.Management.Automation.PSCredential][parameter(Mandatory = $true)]$Credential
	)

	$networkCredential = New-Object -TypeName System.Net.NetworkCredential -ArgumentList @($Credential.UserName, $Credential.Password)
	$httpClientHandler = New-Object -TypeName System.Net.Http.HttpClientHandler
	$httpClientHandler.Credentials = $networkCredential

	return $httpClientHandler
}

Last but not least, a function that actually invokes the post call to our server.

function PostArtifact()
{
	param
	(
		[string][parameter(Mandatory = $true)]$EndpointUrl,
		[System.Net.Http.HttpClientHandler][parameter(Mandatory = $true)]$Handler,
		[System.Net.Http.HttpContent][parameter(Mandatory = $true)]$Content
	)

	$httpClient = New-Object -TypeName System.Net.Http.Httpclient $Handler

	try
	{
		$response = $httpClient.PostAsync("$EndpointUrl/service/local/artifact/maven/content", $Content).Result

		if (!$response.IsSuccessStatusCode)
		{
			$responseBody = $response.Content.ReadAsStringAsync().Result
			$errorMessage = "Status code {0}. Reason {1}. Server reported the following message: {2}." -f $response.StatusCode, $response.ReasonPhrase, $responseBody

			throw [System.Net.Http.HttpRequestException] $errorMessage
		}

		return $response.Content.ReadAsStringAsync().Result
	}
	catch [Exception]
	{
		$PSCmdlet.ThrowTerminatingError($_)
	}
	finally
	{
		if($null -ne $httpClient)
		{
			$httpClient.Dispose()
		}

		if($null -ne $response)
		{
			$response.Dispose()
		}
	}
}

This is all the necessary to upload an artifact to our Nexus server. You can find the just show scripts also on GitHub in the following repository tfs-build-tasks. Further information about programtically uploading artifacts into Nexus can be found in the following post, How can I programatically upload an artifact into Nexus?.

2 thoughts on “Uploading artifacts into Nexus via PowerShell

  1. I’ve been trying to use this script, and I can’t seem to figure out why I get this error message whether or not I use the POM file upload or manual GAV.

    PostArtifact : You cannot call a method on a null-valued expression.
    At C:\nexus1.psm1:50 char:10
    + return PostArtifact $EndpointUrl $httpClientHandler $content
    + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo : InvalidOperation: (:) [PostArtifact], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull,PostArtifact

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