Add reference documentation for DSC.PackageManagement/Apt

CONTRIBUTING.md

@@ -29,7 +29,7 @@ Please read the rest of this document to ensure a smooth contribution process.
 You can contribute to documentation either in the `docs` folder of this repository
 or in the [PowerShell-Docs-DSC](https://github.com/MicrosoftDocs/PowerShell-Docs-DSC/) repository.
 
-> [!INFO]
+> [!NOTE]
 > Documentation contributed to the `docs` folder in this repository is periodically synced to the [PowerShell-Docs-DSC](https://github.com/MicrosoftDocs/PowerShell-Docs-DSC/) repository.
 
 ### Contributing to documentation related to maintaining or contributing to the DSC project

docs/reference/resources/DSC/PackageManagement/APT/examples/manage-packages-with-apt.md

@@ -0,0 +1,105 @@
+---
+description: > 
+    Demonstrates how to manage packages with the DSC.PackageManagement/Apt resource
+ms.date:     06/30/2025
+ms.topic:    reference
+title:       Manage packages with APT
+---
+
+# Manage packages with APT
+
+This example demonstrates how to use the `DSC.PackageManagement/Apt` resource to manage packages on Linux systems
+that use the APT package manager.
+
+## Test if package is installed
+
+The following snippet shows how you can use the resource with the [dsc resource test][00] command
+to check whether the `nginx` package exists.
+
+```bash
+dsc resource test --resource DSC.PackageManagement/Apt --input '{"packageName":"nginx"}'
+```
+
+When the package is not installed, DSC returns the following result.
+
+> [!NOTE]
+> Note that the version and source values can differ depending on your system's package repositories
+> and available package versions.
+
+```yaml
+desiredState:
+  packageName: nginx
+actualState:
+  _exist: false
+  packageName: nginx
+  version: 1.24.0-2ubuntu7.3
+  source: noble-updates,noble-security,now
+inDesiredState: false
+differingProperties:
+  - _exist
+```
+
+## Ensure a package is installed
+
+To ensure the system is in the desired state, use the [dsc resource set][01]
+command.
+
+```bash
+dsc resource set --resource DSC.PackageManagement/Apt --input '{"packageName":"nginx"}'
+```
+
+When the resource installs the package, DSC returns the following result:
+
+```yaml
+beforeState:
+  packageName: "nginx"
+  _exist: false
+afterState:
+  packageName: nginx
+  version: "1.24.0-2ubuntu7.3"
+  source: noble-updates,noble-security,now
+changedProperties:
+- _exist
+```
+
+You can test the instance again to confirm that the package exists:
+
+```bash
+dsc resource test --resource DSC.PackageManagement/Apt --input '{"packageName":"nginx"}'
+```
+
+```yaml
+desiredState:
+  packageName: nginx
+actualState:
+  _exist: true
+  packageName: nginx
+  version: 1.24.0-2ubuntu7.3
+  source: noble-updates,noble-security,now
+inDesiredState: true
+differingProperties: []
+```
+
+## Uninstall a package
+
+To uninstall a package, set the `_exist` property to `false`:
+
+```bash
+dsc resource set --resource DSC.PackageManagement/Apt --input '{"packageName":"nginx", "_exist": false}'
+```
+
+To verify the package no longer exists, use the `dsc resource get` command
+
+```powershell
+dsc resource get --resource DSC.PackageManagement/Apt --input '{"packageName":"nginx"}'
+```
+
+```yaml
+actualState:
+  packageName: nginx
+  _exist: false
+```
+
+<!-- Link reference definitions -->
+[00]: ../../../../../cli/resource/test.md
+[01]: ../../../../../cli/resource/set.md

docs/reference/resources/DSC/PackageManagement/APT/index.md

@@ -0,0 +1,199 @@
+---
+description: DSC.PackageManagement/Apt resource reference documentation
+ms.date:     06/30/2025
+ms.topic:    reference
+title:       DSC.PackageManagement/Apt
+---
+
+# DSC.PackageManagement/Apt
+
+## Synopsis
+
+Manage packages with the advanced package tool (APT) on Linux systems.
+
+> [!IMPORTANT]
+> The `DSC.PackageManagement/Apt` resource is a proof-of-concept example
+> for use with DSC. Don't use it in production.
+
+## Metadata
+
+```yaml
+Version    : 0.1.0
+Kind       : resource
+Tags       : [Linux, apt, PackageManagement]
+Author     : Microsoft
+```
+
+## Instance definition syntax
+
+```yaml
+resources:
+  - name: <instance name>
+    type: DSC.PackageManagement/Apt
+    properties:
+      # Required properties
+      packageName: string
+      # Instance properties
+      _exist: boolean
+      version: string
+```
+
+## Description
+
+The `DSC.PackageManagement/Apt` resource enables you to idempotently manage packages with the Advanced Package Tool (APT) on
+Linux systems. The resource can:
+
+- Install packages
+- Uninstall packages
+- Check if a package is installed
+- Verify the version of an installed package
+
+> [!NOTE]
+> This resource only works on Linux systems that use the APT package manager, such as Ubuntu and Debian.
+
+## Requirements
+
+- A Linux system with APT installed
+- Administrative privileges (root or sudo access) to install and remove packages
+
+## Capabilities
+
+The resource has the following capabilities:
+
+- `get` - You can use the resource to retrieve the actual state of an instance.
+- `set` - You can use the resource to enforce the desired state for an instance.
+- `export` - You can use the resource to export the current state of the system.
+
+This resource uses the synthetic test functionality of DSC to determine whether an instance is in
+the desired state. For more information about resource capabilities, see
+[DSC resource capabilities][00].
+
+## Examples
+
+1. [Manage packages with APT](./examples/manage-packages-with-apt.md) - Shows how to install, uninstall,
+   and check packages with the `DSC.PackageManagement/Apt` resource.
+
+## Properties
+
+The following list describes the properties for the resource.
+
+- **Required properties:** <a id="required-properties"></a> The following properties are always
+  required when defining an instance of the resource. An instance that doesn't define each of these
+  properties is invalid. For more information, see the "Required resource properties" section in
+  [DSC resource properties][01]
+
+  - [packageName](#packagename) - The name of the package to query or install.
+
+- **Key properties:** <a id="key-properties"></a> The following properties uniquely identify an
+  instance. If two instances of a resource have the same values for their key properties, the
+  instances are conflicting. For more information about key properties, see the "Key resource
+  properties" section in [DSC resource properties][02].
+
+  - [packageName](#packagename) (required) - The name of the package to query or install.
+
+- **Instance properties:** <a id="instance-properties"></a> The following properties are optional.
+  They define the desired state for an instance of the resource.
+
+  - [_exist](#_exist) - Defines whether the package should exist.
+  - [version](#version) - The version of the package to install.
+
+- **Read-only properties:** <a id="read-only-properties"></a> The resource returns the following
+  properties, but they aren't configurable. For more information about read-only properties, see
+  the "Read-only resource properties" section in [DSC resource properties][03].
+
+  - [source](#source) - Indicates the source of the package.
+
+### packageName
+
+<details><summary>Expand for <code>packageName</code> property metadata</summary>
+
+```yaml
+Type             : string
+IsRequired       : true
+IsKey            : true
+IsReadOnly       : false
+IsWriteOnly      : false
+```
+
+</details>
+
+Defines the name of the package to query or install. This property is required and serves as the key for uniquely
+identifying the package.
+
+### _exist
+
+<details><summary>Expand for <code>_exist</code> property metadata</summary>
+
+```yaml
+Type             : boolean
+IsRequired       : false
+IsKey            : false
+IsReadOnly       : false
+IsWriteOnly      : false
+DefaultValue     : true
+```
+
+</details>
+
+The `_exist` canonical resource property determines whether a package should exist. When the
+value for `_exist` is `true`, the resource installs the package if it doesn't exist. When
+the value for `_exist` is `false`, the resource removes or uninstalls the package if it does exist.
+The default value for this property when not specified for an instance is `true`.
+
+### version
+
+<details><summary>Expand for <code>version</code> property metadata</summary>
+
+```yaml
+Type             : string
+IsRequired       : false
+IsKey            : false
+IsReadOnly       : false
+IsWriteOnly      : false
+```
+
+</details>
+
+Defines the version of the package to install. If not specified, the latest available version will be installed.
+
+### source
+
+<details><summary>Expand for <code>source</code> property metadata</summary>
+
+```yaml
+Type             : string
+IsRequired       : false
+IsKey            : false
+IsReadOnly       : true
+IsWriteOnly      : false
+```
+
+</details>
+
+Indicates the source of the package. This is a read-only property returned by the resource after a `get` operation.
+
+## Exit codes
+
+The resource returns the following exit codes from operations:
+
+- [0](#exit-code-0) - Success
+- [1](#exit-code-1) - Invalid parameter
+
+### Exit code 0
+
+Indicates the resource operation completed without errors.
+
+### Exit code 1
+
+Indicates the resource operation failed due to an invalid parameter. When the resource returns this
+exit code, it also emits an error message with details about the invalid parameter.
+
+## See also
+
+- [For more information about APT](https://wiki.debian.org/Apt)
+
+<!-- Link definitions -->
+[00]: ../../../../../concepts/resources/capabilities.md
+[01]: ../../../../../concepts/resources/properties.md#required-resource-properties
+[02]: ../../../../../concepts/resources/properties.md#key-resource-properties
+[03]: ../../../../../concepts/resources/properties.md#read-only-resource-properties