asp-net-core-on-arm

Getting ASP.NET Core to run on a Raspberry Pi

Working

.NET Core supports building for multiple architectures via the --runtime / r flag on dotnet publish and dotnet restore. The ASP.NET Core runtime image has multiple different tags for target architectures. Dockerfile builds ASP.NET Core for arm32v7.

docker build . -t dylanmunyard/arm-hello-world:1.2
docker push dylanmunyard/arm-hello-world:1.2

Using buildx - Rabbit hole - Multi-architecture Docker build support

The reason this doesn't work is that .NET Core doesn't support running within QEMU which provides Docker with support for building images for multiple platforms. The solution is to use dotnet core's runtime identifier to publish for the target architecture, and to use the arm32v7 tag of the ASP.NET Core runtime image. source

However these steps do allow you to run remote Docker builds on the Raspberry Pi itself.

https://www.docker.com/blog/getting-started-with-docker-for-arm-on-linux/ is a pretty good overview on how to build Docker images for multiple platforms.

Steps

• Download docker-buildx https://github.com/docker/buildx/releases/tag/v0.2.0
• Copy to ~/.docker/cli-plugins
• Make it executable chmod +x ~/.docker/cli-plugins/docker-buildx
• Confirm it was installed: docker buildx --help:

Usage:	docker buildx COMMAND

Build with BuildKit

Management Commands:
  imagetools  Commands to work on images in registry

Commands:
  bake        Build from a file
  build       Start a build
  create      Create a new builder instance
  inspect     Inspect current builder instance
  ls          List builder instances
  rm          Remove a builder instance
  stop        Stop builder instance
  use         Set the current builder instance
  version     Show buildx version information 

Run 'docker buildx COMMAND --help' for more information on a command.

• Install multi-architecture Dockerfile support: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes\
• Create a docker build instance:

  docker buildx create --name mybuilder
  docker buildx use mybuilder
  docker buildx inspect --bootstrap
  

• The output of inspect should list linux/arm/v7 in the platforms:

Name:   builder
Driver: docker-container

Nodes:
Name:      builder0
Endpoint:  unix:///var/run/docker.sock
Status:    running
Platforms: linux/amd64, linux/arm64, linux/riscv64, linux/ppc64le, linux/s390x, linux/386, linux/arm/v7, linux/arm/v6

Build the image for arm

docker buildx build --platform linux/arm -t dylanmunyard/arm-hello-world:1.1 . --push