Chiselled .NET

Home for the Chiselled Ubuntu images for .NET, by Canonical.

Images

`ubuntu/dotnet-deps`

For those looking to run self-contained .NET applications. This is a tiny image that only contains the minimal set of dependencies for running .NET, but not .NET itself.

`ubuntu/dotnet-runtime`

For those looking to run general-purpose .NET applications. This is a minimalist image, with just the dotnet-runtime-<version> package and its minimal set of dependencies.

`ubuntu/dotnet-aspnet`

For those looking to run ASP.NET applications. This image inherits its content from the ubuntu/dotnet-deps image and only adds the aspnetcore-runtime-<version> package from the Ubuntu archives.

About

These images do not include bash or a package manager.

Read more about Chiselled Ubuntu for .NET, a new class of OCI images, on the Ubuntu blog; reading how Canonical and Microsoft partner together to deliver and support .NET on Ubuntu.

If you're looking to publish a self-contained .NET app, please have a look at the ubuntu/dotnet-deps repository. If you're looking to publish an ASP.NET app, please then look at the ubuntu/dotnet-aspnet repository.

Project Structure

This repository hosts all multiple Chiselled Ubuntu images for multiple versions of .NET.

For automation and release purposes, different versions of .NET are maintained in different channel branches:

.NET 6.0: channels/6.0/edge
.NET 8.0: channels/8.0/edge

The central CI/CD pipelines that take care of automating the build and release for these images, only looks at "channel" branches named according to channels/<version>/<risk>.

Each channel branch will contain one or more Chiselled images.

You'll find more information about each Chiselled .NET image, as well as their build recipes and tests, in each one of their corresponding channel branches.

Building the .NET application image

These chiselled Ubuntu images are typically used as base images for building one's application container image. For example:

FROM ubuntu.azurecr.io/ubuntu:24.04 AS builder
# install the .NET 8 SDK from the Ubuntu archive
# (no need to clean the apt cache as this is an unpublished stage)
RUN apt-get update && apt-get install -y dotnet8 ca-certificates
# add your application code, e.g. for a "Hello" app
WORKDIR /source
COPY src/ .
# publish your .NET app
RUN dotnet publish -c Release -o /app

# Final chiselled image with the .NET application
FROM ubuntu.azurecr.io/dotnet-runtime:8.0-24.04_edge
WORKDIR /app
COPY --from=builder /app ./
EXPOSE 8080
ENTRYPOINT ["dotnet", "/app/Hello.dll"]

Similarly to the above, one can also add more package slices to an existing chiselled Ubuntu image. Here's an example on how to add libicu70 to an ubuntu/dotnet-deps image:

FROM ubuntu.azurecr.io/ubuntu:22.04 AS base
ARG TARGETARCH 
# Get the Chisel binary
ADD https://github.com/canonical/chisel/releases/download/v0.8.0/chisel_v0.8.0_linux_${TARGETARCH}.tar.gz chisel.tar.gz
RUN tar -xf chisel.tar.gz && \
    apt update && \
    apt install -y ca-certificates && \
    mkdir /rootfs && \
    ./chisel cut --root /rootfs libicu70_libs

# Final chiselled image with the libicu70 libraries
FROM ubuntu.azurecr.io/dotnet-deps:6.0-22.04_stable
COPY --from=base /rootfs /

rockcrafters / dotnet

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