Is it possible to run my development asp.net core server out of a docker container - asp.net

Question

When developing node.js projects I will normally use docker compose to bring up an entire stack of docker containers in order to develop on my local host. I mount volumes in and use nodemon to automatically update the running server. This works well. However, it does not seem to work quite the same way with asp.net core.
Is it possible to run a development container for an asp.net core application? I would like to have the server restart when there is a change on the host machine to a file. I know you can do this with the dotnet watch run command but I'm yet to see it working inside a running docker container. How can I get this working within a docker compose stack? What docker base image should I be using? Ideally this solution will work from the command line without using visual studio as I'm using Visual Studio code on a mac.

Answer 1

A little bit late to the party, but maybe it will help someone.
Here is the sample project setup that will leverage dotnet watch command
in a docker container, while source code is being edited on the host system.
As far as I know dotnet watch now is a global tool so you can use it with
different versions of .netcore.
Here is the documentation for
dotnet watch command.
Sample project overview
Here is a small example project for demo purposes, made with help of minimal api.
It has one endpoint /freshbread which returns "Baked bread".
Folder structure:
Bakery
│ Dockerfile
└───src
│───Bakery.csproj
└───Program.cs
Content of Program.cs:
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/freshbread", () => "Baked bread");
app.Run("http://*:80");
Content of Bakery.csproj
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>net6.0</TargetFramework>
<Nullable>enable</Nullable>
<ImplicitUsings>enable</ImplicitUsings>
</PropertyGroup>
</Project>
Content of Dockerfile:
FROM mcr.microsoft.com/dotnet/sdk:6.0
WORKDIR /app
ENTRYPOINT ["dotnet", "watch"]
Based on a Microsoft .net core SDK image. It just defines an /app workdir and launches there dotnet watch command.
The "trick" here is to mount into /app folder your source code from the host machine and let container handle compilation
and server restart, so:
Build an image (from Bakery folder):
docker build -t dev-container .
Run a container:
docker run \
--rm \
--detach \
--volume /path/to/the/Bakery/src:/app \
--publish 5000:80
dev-container
Publish port outside, so api will be accessible from the host machine.
Now, container is watching files in mounted folder and whenever there are chages
it will perform hot-reload.
Demo
Here is a short demo of this setup, note that top and bottom-right splits are host machine terminals and bottom-left split is log of the container.