Introducing Built-In Container Support for the .NET SDK

In this post, let's see how we can create a containerized version of our application by doing just dotnet publish. Note: In order to do this, you’ll need .NET SDK 7.0.100, preview 7 or greater  installed and currently only supported for Web Projects (Microsoft.NET.Sdk.Web).

Let's start with a simple example. Here I am creating a Blazor Server App using the default template.

dotnet new blazorserver -n hello-blazor-container
cd .\hello-blazor-container\

Next, we need to install this new package: Microsoft.NET.Build.Containers. This is the package that lets us build container image from the project.

# add a reference to package that creates the container
dotnet add package Microsoft.NET.Build.Containers

And now this is what our .csproj looks like.

<Project Sdk="Microsoft.NET.Sdk.Web">
 
  <PropertyGroup>
    <TargetFramework>net7.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <RootNamespace>hello_blazor_container</RootNamespace>
  </PropertyGroup>
 
 <ItemGroup>
    <PackageReference Include="Microsoft.NET.Build.Containers" Version="0.1.8" />
  </ItemGroup>
  
</Project>

And that's mostly it. All we need to do now is running dotnet publish, setting PublishProfile=DefaultContainer.

# publish
dotnet publish --os linux --arch x64 -p:PublishProfile=DefaultContainer

docker publish

Alternatively, you can update the csproj file as follows and then you can just run dotnet publish without supplying any arguments.

<Project Sdk="Microsoft.NET.Sdk.Web">
 
  <PropertyGroup>
    <TargetFramework>net7.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <RootNamespace>hello_blazor_container</RootNamespace>
 
    <RuntimeIdentifier>linux-x64</RuntimeIdentifier>
    <PublishProfile>DefaultContainer</PublishProfile>
  </PropertyGroup>
 
 <ItemGroup>
    <PackageReference Include="Microsoft.NET.Build.Containers" Version="0.1.8" />
  </ItemGroup>
  
</Project>

Now if we examine our local docker images, I can see the new image is created.

docker images

Now let's create a container and run it.

# run the application as a container
docker run -it --rm -p 5000:80 hello-blazor-container:1.0.0

docker run

Now if I open up http://localhost:5000, I can see the application is up and running.

Running Container

You can customize the generated container through MSBuild properties. 

To learn more about this feature, read:

   Announcing built-in container support for the .NET SDK

   .NET SDK Container Building Tools

Happy Coding.

Regards,

Jaliya