IIS Versioned Deploy

Deploy a website (and optionally a virtual application within it) to IIS with reduced downtime by switching the site's physical path to a freshly copied, versioned release folder.

This extension adds the IIS Versioned App Deployment task to your Azure Pipelines so you can release ASP.NET / IIS sites without leaving the published files locked or serving a half-copied directory.

Requirements

• A self-hosted Windows agent on the target machine.
• IIS installed with the PowerShell WebAdministration module available.
• An existing IIS website (and virtual application, if you deploy one).

How it works

The task copies your published output into a new versioned directory inside the destination path and then repoints IIS at it. The directories are named using the pattern r_<version>, for example r_1, r_2, etc.

When a new deployment runs:

1. A new directory is created (e.g. r_5).
2. The site content is copied into this new directory.
3. The IIS website (or virtual application) physical path is updated to point to the new directory.
4. Old directories are cleaned up, keeping only the number specified in Number of releases to keep.

Example structure in C:\inetpub\website-releases:

r_3
r_4
r_5  <-- IIS points here

Because IIS is only switched to the new folder once the copy has completed, downtime is minimal and rollbacks are as simple as repointing to a previous r_<version> directory.

Inputs

Usage

Add the task to a pipeline that runs on a self-hosted Windows agent:

- task: IISVersionedAppDeployment@0
  inputs:
    WebSiteName: 'MyWebsite'
    AppName: 'virtual_app'        # optional
    SourcePath: '$(System.DefaultWorkingDirectory)/website/publish'
    DestinationPath: 'C:\inetpub\website-releases'
    NumberToKeep: 2

The task runs on the Node 20 handler and shells out to a PowerShell deployment script, so the agent must have IIS and the WebAdministration module available.

Support

This extension is open source. Source code, issue tracking, and additional documentation (including AppCmd operational guidance) are available on GitHub.

License

Released under the MIT License.