You can use containers to establish a .NET development environment with only Docker and an editor. The environment can be made to match your local machine, production or both.
The following examples demonstrate using dotnet run in a .NET SDK container. It builds an application from source and then launches it. You have to re-launch the container every time you want to observe source code changes.
Alternatively, you can use dotnet watch run. This command reruns the application within a running container, with every local code change.
The instructions assume that you have cloned the repository locally.
You may need to enable shared drives (Windows) or file sharing (macOS) first.
Container scenarios that use volume mounting can produce conflicts between the bin and obj directories in local and container environments. To avoid that, you need to use a different set of obj and bin folders for your container environment. The easiest way to do that is to copy a custom Directory.Build.props into the directory you are using (like the dotnetapp directory in the following example), either via copying from this repo or downloading with the following command:
curl -o Directory.Build.props https://github.com/dotnet/dotnet-docker/main/samples/Directory.Build.propsNote
You may need to remove bin and obj directories if you run these instructions on Windows in both Windows and Linux container modes.
The following example demonstrates using dotnet run with a console app in a .NET SDK container. This initial example is demonstrated on macOS. Instructions for all OSes follow.
The instructions assume you are in the samples/dotnetapp directory (due to the volume mounting -v syntax).
% docker run --rm -it -v $(pwd):/app/ -w /app mcr.microsoft.com/dotnet/sdk:8.0 dotnet run
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OSArchitecture: X64
OSDescription: Debian GNU/Linux 12 (bookworm)
FrameworkDescription: .NET 8.0.0
UserName: root
HostName : 0dea5548ae88
ProcessorCount: 16
TotalAvailableMemoryBytes: 33632350208 (31.32 GiB)You can test this working by simply editing Program.cs. If you make an observable change, you will see it. If you make a syntax error, you will see compiler errors.
The following instructions demonstrate this scenario in various environments.
docker run --rm -it -v $(pwd):/app/ -w /app mcr.microsoft.com/dotnet/sdk:8.0 dotnet runThis example uses PowerShell.
docker run --rm -it -v ${pwd}:/app/ -w /app mcr.microsoft.com/dotnet/sdk:8.0 dotnet runThis example uses PowerShell.
docker run --rm -it -v ${pwd}:c:\app\ -w \app mcr.microsoft.com/dotnet/sdk:8.0 dotnet runThe following example demonstrates using dotnet run with an ASP.NET Core app in a .NET SDK container. This initial example is demonstrated on macOS. Instructions for all OSes follow.
The instructions assume you are in the samples/aspnetapp/aspnetapp directory (due to the volume mounting -v syntax used).
% docker run --rm -it -p 8000:8080 -v $(pwd):/app/ -w /app -e ASPNETCORE_HTTP_URLS=8080 -e ASPNETCORE_ENVIRONMENT=Development mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --no-launch-profile
info: Microsoft.Hosting.Lifetime[0]
Now listening on: http://[::]:8080
info: Microsoft.Hosting.Lifetime[0]
Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
Hosting environment: Development
info: Microsoft.Hosting.Lifetime[0]
Content root path: /appYou can use CTRL-C to terminate dotnet run. After the application starts, navigate to http://localhost:8000 in your web browser.
Note
This example (and those in the instructions that follow) configure ASP.NET Core via environment variables and disable the use of a launch profile (none of the launch profiles are compatible with this scenario). Instructions are provided later in this document that add and use a new launch profile, which removes the need for specifying environment variables with the Docker CLI.
The following instructions demonstrate this scenario in various environments:
docker run --rm -it -p 8000:8080 -v $(pwd):/app/ -w /app -e ASPNETCORE_HTTP_URLS=8080 -e ASPNETCORE_ENVIRONMENT=Development mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --no-launch-profileThis example uses PowerShell.
docker run --rm -it -p 8000:8080 -v ${pwd}:/app/ -w /app -e ASPNETCORE_HTTP_URLS=8080 -e ASPNETCORE_ENVIRONMENT=Development mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --no-launch-profileThis example uses PowerShell.
docker run --rm -it -p 8000:8080 -v ${pwd}:C:\app\ -w \app -e ASPNETCORE_HTTP_URLS=8080 -e ASPNETCORE_ENVIRONMENT=Development mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --no-launch-profileThe examples above use environment variables to configure ASP.NET Core. You can instead configure ASP.NET Core with a launchSettings.json file. The launchSettings.json file in this app has been updated with a container profile that can be used instead of specifying environment variables with the docker CLI.
The following JSON segment shows the container profile that was added to enable this workflow.
"publicdev": {
"commandName": "Project",
"launchBrowser": true,
"applicationUrl": "http://+:8080",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
}The following instructions demonstrate this scenario in various environments:
docker run --rm -it -p 8000:8080 -v $(pwd):/app -w /app mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --launch-profile publicdevThe following example uses PowerShell.
docker run --rm -it -p 8000:8080 -v ${pwd}:/app -w /app mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --launch-profile publicdevThe following example uses PowerShell.
docker run --rm -it -p 8000:8080 -v ${pwd}:C:\app -w C:\app mcr.microsoft.com/dotnet/sdk:8.0 dotnet run --launch-profile publicdev