setup-dotnet/README.md

# setup-dotnet

[![Basic validation](https://github.com/actions/setup-dotnet/actions/workflows/basic-validation.yml/badge.svg?branch=main)](https://github.com/actions/setup-dotnet/actions/workflows/basic-validation.yml)
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This action sets up a [.NET CLI](https://github.com/dotnet/sdk) environment for use in actions by:

- optionally downloading and caching a version(s) of dotnet by SDK version(s) and adding to PATH
- registering problem matchers for error output
- setting up authentication to private package sources like GitHub Packages

> **Note**: GitHub hosted runners have some versions of the .NET SDK
preinstalled. Installed versions are subject to change. Please refer to the
documentation:
[Software installed on github hosted runners](https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#supported-software)
for .NET SDK versions that are currently available.

## Usage

See [action.yml](action.yml)

**Basic**:
```yaml
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: '3.1.x'
- run: dotnet build <my project>
```
> **Warning**: Unless a concrete version is specified in the [`global.json`](https://learn.microsoft.com/en-us/dotnet/core/tools/global-json) file, **_the latest .NET version installed on the runner (including preinstalled versions) will be used [by default](https://learn.microsoft.com/en-us/dotnet/core/versions/selection#the-sdk-uses-the-latest-installed-version)_**. Please refer to the [documentation](https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#supported-software) for the currently preinstalled .NET SDK versions.

**Multiple version installation**:
```yml
steps:
- uses: actions/checkout@v4
- name: Setup dotnet
  uses: actions/setup-dotnet@v4
  with:
    dotnet-version: | 
      3.1.x
      5.0.x
- run: dotnet build <my project>
```
## Supported version syntax

The `dotnet-version` input supports following syntax:

- **A.B.C** (e.g 6.0.400, 7.0.100-preview.7.22377.5) - installs exact version of .NET SDK
- **A.B** or **A.B.x** (e.g. 3.1, 3.1.x) - installs the latest patch version of .NET SDK on the channel `3.1`, including prerelease versions (preview, rc)
- **A** or **A.x** (e.g. 3, 3.x) - installs the latest minor version of the specified major tag, including prerelease versions (preview, rc)
- **A.B.Cxx** (e.g. 6.0.4xx) - available since `.NET 5.0` release. Installs the latest version of the specific SDK release, including prerelease versions (preview, rc). 


## Using the `dotnet-quality` input
This input sets up the action to install the latest build of the specified quality in the channel. The possible values of `dotnet-quality` are: **daily**, **signed**, **validated**, **preview**, **ga**.

> **Note**: `dotnet-quality` input can be used only with .NET SDK version in 'A.B', 'A.B.x', 'A', 'A.x' and 'A.B.Cxx' formats where the major version is higher than 5. In other cases, `dotnet-quality` input will be ignored.

```yml
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: '6.0.x'
    dotnet-quality: 'preview'
- run: dotnet build <my project>
```

## Using the `global-json-file` input
`setup-dotnet` action can read .NET SDK version from a `global.json` file. Input `global-json-file` is used for specifying the path to the `global.json`. If the file that was supplied to `global-json-file` input doesn't exist, the action will fail with error.

>**Note**: In case both `dotnet-version` and `global-json-file` inputs are used, versions from both inputs will be installed.

```yml
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    global-json-file: csharp/global.json
- run: dotnet build <my project>
  working-directory: csharp
```

## Caching NuGet Packages
The action has a built-in functionality for caching and restoring dependencies. It uses [toolkit/cache](https://github.com/actions/toolkit/tree/main/packages/cache) under the hood for caching global packages data but requires less configuration settings. The `cache` input is optional, and caching is turned off by default.

The action searches for [NuGet Lock files](https://learn.microsoft.com/nuget/consume-packages/package-references-in-project-files#locking-dependencies) (`packages.lock.json`) in the repository root, calculates their hash and uses it as a part of the cache key. If lock file does not exist, this action throws error. Use `cache-dependency-path` for cases when multiple dependency files are used, or they are located in different subdirectories.

> **Warning**: Caching NuGet packages is available since .NET SDK 2.1.500 and 2.2.100 as the NuGet lock file [is available](https://learn.microsoft.com/nuget/consume-packages/package-references-in-project-files#locking-dependencies) only for NuGet 4.9 and above.

```yaml
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: 6.x
    cache: true
- run: dotnet restore --locked-mode
```

> **Note**: This action will only restore `global-packages` folder, so you will probably get the [NU1403](https://learn.microsoft.com/nuget/reference/errors-and-warnings/nu1403) error when running `dotnet restore`.
> To avoid this, you can use [`DisableImplicitNuGetFallbackFolder`](https://github.com/dotnet/reproducible-builds/blob/abfe986832aa28597d3340b92469d1a702013d23/Documentation/Reproducible-MSBuild/Techniques/DisableImplicitNuGetFallbackFolder.md) option.

```xml
<PropertyGroup>
  <DisableImplicitNuGetFallbackFolder>true</DisableImplicitNuGetFallbackFolder>
</PropertyGroup>
```

### Reduce caching size

> **Note**: Use [`NUGET_PACKAGES`](https://learn.microsoft.com/nuget/reference/cli-reference/cli-ref-environment-variables) environment variable if available. Some action runners already has huge libraries. (ex. Xamarin)

```yaml
env:
  NUGET_PACKAGES: ${{ github.workspace }}/.nuget/packages
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: 6.x
    cache: true
- run: dotnet restore --locked-mode
```

### Caching NuGet packages in monorepos

```yaml
env:
  NUGET_PACKAGES: ${{ github.workspace }}/.nuget/packages
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: 6.x
    cache: true
    cache-dependency-path: subdir/packages.lock.json
- run: dotnet restore --locked-mode
```

## Matrix Testing
Using `setup-dotnet` it's possible to use [matrix syntax](https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstrategymatrix) to install several versions of .NET SDK:
```yml
jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        dotnet: [ '2.1.x', '3.1.x', '5.0.x' ]
    name: Dotnet ${{ matrix.dotnet }} sample
    steps:
      - uses: actions/checkout@v4
      - name: Setup dotnet
        uses: actions/setup-dotnet@v4
        with:
          dotnet-version: ${{ matrix.dotnet }}
      - name: Execute dotnet
        run: dotnet build <my project>
```
>**Note**: Unless a concrete version is specified in the [`global.json`](https://learn.microsoft.com/en-us/dotnet/core/tools/global-json) file, the latest .NET version installed on the runner (including preinstalled versions) will be used [by default](https://learn.microsoft.com/en-us/dotnet/core/versions/selection#the-sdk-uses-the-latest-installed-version). To control this behavior you may want to use temporary `global.json` files:

**Matrix testing with temporary global.json creation**
```yml
jobs:
  build:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        dotnet: [ '2.1.x', '3.1.x', '5.0.x' ]
    name: Dotnet ${{ matrix.dotnet }} sample
    steps:
      - uses: actions/checkout@v4
      - name: Setup dotnet
        uses: actions/setup-dotnet@v4
        id: stepid
        with:
          dotnet-version: ${{ matrix.dotnet }}
      - name: Create temporary global.json
        run: echo '{"sdk":{"version": "${{ steps.stepid.outputs.dotnet-version }}"}}' > ./global.json
      - name: Execute dotnet
        run: dotnet build <my project>
```
## Setting up authentication for nuget feeds

### Github Package Registry (GPR)
```yml
steps:
- uses: actions/checkout@v4
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: '3.1.x'
    source-url: https://nuget.pkg.github.com/<owner>/index.json
  env:
    NUGET_AUTH_TOKEN: ${{secrets.GITHUB_TOKEN}}
- run: dotnet build <my project>
- name: Create the package
  run: dotnet pack --configuration Release <my project>
- name: Publish the package to GPR
  run: dotnet nuget push <my project>/bin/Release/*.nupkg
```

### Azure Artifacts
```yml
- uses: actions/setup-dotnet@v4
  with:
    source-url: https://pkgs.dev.azure.com/<your-organization>/_packaging/<your-feed-name>/nuget/v3/index.json
  env:
    NUGET_AUTH_TOKEN: ${{secrets.AZURE_DEVOPS_PAT}} # Note, create a secret with this name in Settings
- name: Publish the package to Azure Artifacts
  run: dotnet nuget push <my project>/bin/Release/*.nupkg
```

### nuget.org
```yml
- uses: actions/setup-dotnet@v4
  with:
    dotnet-version: 3.1.x
- name: Publish the package to nuget.org
  run: dotnet nuget push */bin/Release/*.nupkg -k $NUGET_AUTH_TOKEN -s https://api.nuget.org/v3/index.json
  env:
    NUGET_AUTH_TOKEN: ${{ secrets.NUGET_TOKEN }}
```
> **Note**: It's the only way to push a package to nuget.org feed for macOS/Linux machines due to API key config store limitations.

# Outputs and environment variables

## Outputs

### `dotnet-version`

Using the **dotnet-version** output it's possible to get the installed by the action .NET SDK version. 

**Single version installation**

In case of a single version installation, the `dotnet-version` output contains the version that is installed by the action.

```yaml
    - uses: actions/setup-dotnet@v4
      id: stepid
      with:
        dotnet-version: 3.1.422
    - run: echo '${{ steps.stepid.outputs.dotnet-version }}' # outputs 3.1.422
```

**Multiple version installation**

In case of a multiple version installation, the `dotnet-version` output contains the latest version that is installed by the action.

```yaml
    - uses: actions/setup-dotnet@v4
      id: stepid
      with:
        dotnet-version: | 
          3.1.422
          5.0.408
    - run: echo '${{ steps.stepid.outputs.dotnet-version }}' # outputs 5.0.408
```
**Installation from global.json**

When the `dotnet-version` input is used along with the `global-json-file` input, the `dotnet-version` output contains the version resolved from the `global.json`.

```yaml
    - uses: actions/setup-dotnet@v4
      id: stepid
      with:
        dotnet-version: | 
          3.1.422
          5.0.408
        global-json-file: "./global.json" # contains version 2.2.207
    - run: echo '${{ steps.stepid.outputs.dotnet-version }}' # outputs 2.2.207
```

### `cache-hit`
A boolean value to indicate an exact match was found for the cache key (follows [actions/cache](https://github.com/actions/cache#outputs))

## Environment variables

Some environment variables may be necessary for your particular case or to improve logging. Some examples are listed below, but the full list with complete details can be found here: https://docs.microsoft.com/en-us/dotnet/core/tools/dotnet-environment-variables

| **Env.variable**      | **Description** | **Default value** |
| ----------- | ----------- | ----------- |
| DOTNET_INSTALL_DIR      |Specifies a directory where .NET SDKs should be installed by the action.|*default value for each OS* |
| DOTNET_NOLOGO      |Removes logo and telemetry message from first run of dotnet cli|*false*|
| DOTNET_CLI_TELEMETRY_OPTOUT   |Opt-out of telemetry being sent to Microsoft|*false*|
| DOTNET_MULTILEVEL_LOOKUP   |Configures whether the global install location is used as a fall-back|*true*|
| NUGET_PACKAGES |Configures a path to the [NuGet `global-packages` folder](https://learn.microsoft.com/nuget/consume-packages/managing-the-global-packages-and-cache-folders)|*default value for each OS* |

The default values of the `DOTNET_INSTALL_DIR` and `NUGET_PACKAGES` environment variables depend on the operation system which is used on a runner:
| **Operation system** | `DOTNET_INSTALL_DIR` | `NUGET_PACKAGES` |
| ----------- | ----------- | ----------- |
| **Windows** | `C:\Program Files\dotnet` | `%userprofile%\.nuget\packages` |
| **Ubuntu** | `/usr/share/dotnet` | `~/.nuget/packages` |
| **macOS** | `/Users/runner/.dotnet` | `~/.nuget/packages` |

**Example usage of environment variable**:
```yml
build:
  runs-on: ubuntu-latest
  env:
    DOTNET_INSTALL_DIR: "path/to/directory"
    NUGET_PACKAGES: ${{ github.workspace }}/.nuget/packages
  steps:
    - uses: actions/checkout@main
    - uses: actions/setup-dotnet@v4
      with:
        dotnet-version: '3.1.x'
        cache: true
```

## License

The scripts and documentation in this project are released under the [MIT License](LICENSE)

## Contributions

Contributions are welcome! See [Contributor's Guide](docs/contributors.md)