🟣 High-Performance .NET Multi-Stage

Production Dockerfile for ASP.NET Core

Multi-stage build compiling C# applications with the full .NET SDK and running with the optimized ASP.NET Core runtime image.

Dockerfile .NET 8.0 SDK & Runtime

# 1. SDK build stage
FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
WORKDIR /src

# Copy project file and restore NuGet packages
COPY *.csproj ./
RUN dotnet restore

# Copy source and publish release binaries
COPY . ./
RUN dotnet publish -c Release -o /app/publish --no-restore

# 2. Optimized runtime stage
FROM mcr.microsoft.com/dotnet/aspnet:8.0-alpine AS runtime
WORKDIR /app

ENV ASPNETCORE_URLS=http://+:8080
ENV DOTNET_EnableDiagnostics=0

# Use non-root container user built into modern .NET images
USER $APP_UID

COPY --from=build /app/publish .

EXPOSE 8080

ENTRYPOINT ["dotnet", "MyApi.dll"]

Key Highlights

SDK vs Runtime: The massive 800MB+ SDK image is discarded; the final Alpine runtime footprint is only ~100MB.
USER $APP_UID: Uses official .NET 8 non-root UID 1654 for strict container security standards.
Layer Optimization: dotnet restore runs prior to copying application logic to leverage Docker caching.