container-publish

Container Publishing (No Dockerfile)

Core Principles

1. No Dockerfile needed — The .NET 10 SDK builds OCI-compliant container images directly from dotnet publish /t:PublishContainer. No Dockerfile to write or maintain.
2. Chiseled images for production — Use noble-chiseled base images: no shell, no package manager, 7 Linux components vs 100+. Smallest attack surface.
3. Non-root by default — .NET 10 container images run as the app user automatically. Never override to root in production.
4. Configuration in the .csproj — All container settings are MSBuild properties, versioned with your project. No separate files to drift.

Patterns

Minimal Container Publish

No project file changes needed. Just publish:

dotnet publish /t:PublishContainer --os linux --arch x64

This creates a container image in your local Docker daemon using the default aspnet:10.0 base image.

Production-Ready .csproj Configuration

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <ContainerRepository>mycompany/myapp-api</ContainerRepository>
    <ContainerFamily>noble-chiseled</ContainerFamily>
  </PropertyGroup>

  <ItemGroup>
    <ContainerPort Include="8080" Type="tcp" />
    <ContainerEnvironmentVariable Include="ASPNETCORE_HTTP_PORTS" Value="8080" />
    <ContainerEnvironmentVariable Include="DOTNET_EnableDiagnostics" Value="0" />
    <ContainerLabel Include="org.opencontainers.image.vendor" Value="MyCompany" />
  </ItemGroup>

</Project>

Publishing to a Registry

Authenticate with docker login first, then specify the registry:

# GitHub Container Registry
docker login ghcr.io
dotnet publish /t:PublishContainer --os linux --arch x64 \
    -p ContainerRegistry=ghcr.io \
    -p ContainerImageTag=1.0.0

# Azure Container Registry
az acr login --name myregistry
dotnet publish /t:PublishContainer --os linux --arch x64 \
    -p ContainerRegistry=myregistry.azurecr.io

# Docker Hub (requires username prefix in repository)
dotnet publish /t:PublishContainer --os linux --arch x64 \
    -p ContainerRegistry=docker.io \
    -p ContainerRepository=myuser/myapp