# .NET

## Featured Repos

* [dotnet/sdk](https://github.com/dotnet/dotnet-docker/blob/main/README.sdk.md): .NET SDK
* [dotnet/aspnet](https://github.com/dotnet/dotnet-docker/blob/main/README.aspnet.md): ASP.NET Core Runtime
* [dotnet/runtime](https://github.com/dotnet/dotnet-docker/blob/main/README.runtime.md): .NET Runtime
* [dotnet/runtime-deps](https://github.com/dotnet/dotnet-docker/blob/main/README.runtime-deps.md): .NET Runtime Dependencies
* [dotnet/monitor](https://github.com/dotnet/dotnet-docker/blob/main/README.monitor.md): .NET Monitor Tool
* [dotnet/aspire-dashboard](https://github.com/dotnet/dotnet-docker/blob/main/README.aspire-dashboard.md): .NET Aspire Dashboard
* [dotnet/samples](https://github.com/dotnet/dotnet-docker/blob/main/README.samples.md): .NET Samples

## About

[.NET](https://docs.microsoft.com/dotnet/core/) is a general purpose development platform maintained by Microsoft and the .NET community on [GitHub](https://github.com/dotnet/core). It is cross-platform, supports Windows, macOS, and Linux, and can be used in device, cloud, and embedded/IoT scenarios.

.NET has several capabilities that make development productive, including automatic memory management, (runtime) generic types, reflection, [asynchronous constructs](https://learn.microsoft.com/dotnet/csharp/async), concurrency, and native interop. Millions of developers take advantage of these capabilities to efficiently build high-quality applications.

You can use C# or F# to write .NET apps.

* [C#](https://docs.microsoft.com/dotnet/csharp/) is powerful, type-safe, and object-oriented while retaining the expressiveness and elegance of C-style languages. Anyone familiar with C and similar languages will find it straightforward to write in C#.
* [F#](https://docs.microsoft.com/dotnet/fsharp/) is a cross-platform, open-source, functional programming language for .NET. It also includes object-oriented and imperative programming.

[.NET](https://github.com/dotnet/core) is open source (MIT and Apache 2 licenses) and was contributed to the [.NET Foundation](http://dotnetfoundation.org) by Microsoft in 2014. It can be freely adopted by individuals and companies, including for personal, academic or commercial purposes. Multiple companies use .NET as part of apps, tools, new platforms and hosting services.

You are invited to [contribute new features](https://github.com/dotnet/core/blob/master/CONTRIBUTING.md), fixes, or updates, large or small; we are always thrilled to receive pull requests, and do our best to process them as fast as we can.

> [.NET Documentation](https://docs.microsoft.com/dotnet/core/)

Watch [discussions](https://github.com/dotnet/dotnet-docker/discussions/categories/announcements) for Docker-related .NET announcements.

### New: Ubuntu Chiseled Images

Ubuntu Chiseled .NET images are a type of "distroless" container image that contain only the minimal set of packages .NET needs, with everything else removed.
These images offer dramatically smaller deployment sizes and attack surface by including only the minimal set of packages required to run .NET applications.

Please see the [Ubuntu Chiseled + .NET](https://github.com/dotnet/dotnet-docker/blob/main/documentation/ubuntu-chiseled.md) documentation page for more info.

## Usage

The [.NET Docker samples](https://github.com/dotnet/dotnet-docker/blob/main/samples/README.md) show various ways to use .NET and Docker together. See [Building Docker Images for .NET Applications](https://docs.microsoft.com/dotnet/core/docker/building-net-docker-images) to learn more.

### Container sample: Run a simple application

You can quickly run a container with a pre-built [.NET Docker image](https://github.com/dotnet/dotnet-docker/blob/main/README.samples.md), based on the [.NET console sample](https://github.com/dotnet/dotnet-docker/blob/main/samples/dotnetapp/README.md).

Type the following command to run a sample console application:

```console
docker run --rm mcr.microsoft.com/dotnet/samples
```

### Container sample: Run a web application

You can quickly run a container with a pre-built [.NET Docker image](https://github.com/dotnet/dotnet-docker/blob/main/README.samples.md), based on the [ASP.NET Core sample](https://github.com/dotnet/dotnet-docker/blob/main/samples/aspnetapp/README.md).

Type the following command to run a sample web application:

```console
docker run -it --rm -p 8000:8080 --name aspnetcore_sample mcr.microsoft.com/dotnet/samples:aspnetapp
```

After the application starts, navigate to `http://localhost:8000` in your web browser. You can also view the ASP.NET Core site running in the container from another machine with a local IP address such as `http://192.168.1.18:8000`.

> Note: ASP.NET Core apps (in official images) listen to [port 8080 by default](https://github.com/dotnet/dotnet-docker/blob/6da64f31944bb16ecde5495b6a53fc170fbe100d/src/runtime-deps/8.0/bookworm-slim/amd64/Dockerfile#L7), starting with .NET 8. The [`-p` argument](https://docs.docker.com/engine/reference/commandline/run/#publish) in these examples maps host port `8000` to container port `8080` (`host:container` mapping). The container will not be accessible without this mapping. ASP.NET Core can be [configured to listen on a different or additional port](https://learn.microsoft.com/aspnet/core/fundamentals/servers/kestrel/endpoints).

See [Hosting ASP.NET Core Images with Docker over HTTPS](https://github.com/dotnet/dotnet-docker/blob/main/samples/host-aspnetcore-https.md) to use HTTPS with this image.

## Image Variants

.NET container images have several variants that offer different combinations of flexibility and deployment size.
The [Image Variants documentation](https://github.com/dotnet/dotnet-docker/blob/main/documentation/image-variants.md) contains a summary of the image variants and their use-cases.

## Related Repositories

.NET:

* [dotnet/nightly/sdk](https://github.com/dotnet/dotnet-docker/blob/nightly/README.sdk.md): .NET SDK (Preview)
* [dotnet/nightly/aspnet](https://github.com/dotnet/dotnet-docker/blob/nightly/README.aspnet.md): ASP.NET Core Runtime (Preview)
* [dotnet/nightly/runtime](https://github.com/dotnet/dotnet-docker/blob/nightly/README.runtime.md): .NET Runtime (Preview)
* [dotnet/nightly/runtime-deps](https://github.com/dotnet/dotnet-docker/blob/nightly/README.runtime-deps.md): .NET Runtime Dependencies (Preview)
* [dotnet/nightly/monitor](https://github.com/dotnet/dotnet-docker/blob/nightly/README.monitor.md): .NET Monitor Tool (Preview)
* [dotnet/nightly/aspire-dashboard](https://github.com/dotnet/dotnet-docker/blob/nightly/README.aspire-dashboard.md): .NET Aspire Dashboard (Preview)

.NET Framework:

* [dotnet/framework](https://github.com/microsoft/dotnet-framework-docker/blob/main/README.md): .NET Framework, ASP.NET and WCF
* [dotnet/framework/samples](https://github.com/microsoft/dotnet-framework-docker/blob/main/README.samples.md): .NET Framework, ASP.NET and WCF Samples

## Support

### Lifecycle

* [Microsoft Support for .NET](https://github.com/dotnet/core/blob/main/support.md)
* [Supported Container Platforms Policy](https://github.com/dotnet/dotnet-docker/blob/main/documentation/supported-platforms.md)
* [Supported Tags Policy](https://github.com/dotnet/dotnet-docker/blob/main/documentation/supported-tags.md)

### Image Update Policy

* **Base Image Updates:** Images are re-built within 12 hours of any updates to their base images (e.g. debian:bookworm-slim, windows/nanoserver:ltsc2022, etc.).
* **.NET Releases:** Images are re-built as part of releasing new .NET versions. This includes new major versions, minor versions, and servicing releases.
* **Critical CVEs:** Images are re-built to pick up critical CVE fixes as described by the CVE Update Policy below.
* **Monthly Re-builds:** Images are re-built monthly, typically on the second Tuesday of the month, in order to pick up lower-severity CVE fixes.
* **Out-Of-Band Updates:** Images can sometimes be re-built when out-of-band updates are necessary to address critical issues. If this happens, new fixed version tags will be updated according to the [Fixed version tags documentation](https://github.com/dotnet/dotnet-docker/blob/main/documentation/supported-tags.md#fixed-version-tags).

#### CVE Update Policy

.NET container images are regularly monitored for the presence of CVEs. A given image will be rebuilt to pick up fixes for a CVE when:

* We detect the image contains a CVE with a [CVSS](https://nvd.nist.gov/vuln-metrics/cvss) score of "Critical"
* **AND** the CVE is in a package that is added in our Dockerfile layers (meaning the CVE is in a package we explicitly install or any transitive dependencies of those packages)
* **AND** there is a CVE fix for the package available in the affected base image's package repository.

Please refer to the [Security Policy](https://github.com/dotnet/dotnet-docker/blob/main/SECURITY.md) and [Container Vulnerability Workflow](https://github.com/dotnet/dotnet-docker/blob/main/documentation/vulnerability-reporting.md) for more detail about what to do when a CVE is encountered in a .NET image.

### Feedback

* [File an issue](https://github.com/dotnet/dotnet-docker/issues/new/choose)
* [Contact Microsoft Support](https://support.microsoft.com/contactus/)

## License

* Legal Notice: [Container License Information](https://aka.ms/mcr/osslegalnotice)
* [.NET license](https://github.com/dotnet/dotnet-docker/blob/main/LICENSE)
* [Discover licensing for Linux image contents](https://github.com/dotnet/dotnet-docker/blob/main/documentation/image-artifact-details.md)
* [Windows base image license](https://docs.microsoft.com/virtualization/windowscontainers/images-eula) (only applies to Windows containers)
* [Pricing and licensing for Windows Server](https://www.microsoft.com/cloud-platform/windows-server-pricing)