如何使用"dotnet watch run"使用.Net Core 3，Visual Studio 2019和Docker [英] How to use "dotnet watch run" with .Net Core 3, Visual Studio 2019 and docker

问题描述

我正在使用Visual Studio 2019使用Docker和.NET Core3.我通过将Dockerfile添加到我的项目中来对我的应用进行容器化(右键单击该项目->添加-> Docker支持)，并且能够启动它，但是现在我想在容器内使用 dotnet watch run .

I'm playing with docker and .NET Core 3 using Visual Studio 2019. I containerize my application by adding the Dockerfile to my project (right click on the project -> Add -> Docker Support) and I was able to launch it, but now I want to use dotnet watch run inside the container.

这是生成的Dockerfile:

This is the generated Dockerfile:

FROM mcr.microsoft.com/dotnet/core/aspnet:3.0-buster-slim AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
WORKDIR /src
COPY ["DockerTestApp/DockerTestApp.csproj", "DockerTestApp/"]
RUN dotnet restore "DockerTestApp/DockerTestApp.csproj"
COPY . .
WORKDIR "/src/DockerTestApp"
RUN dotnet build "DockerTestApp.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "DockerTestApp.csproj" -c Release -o /app/publish

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "DockerTestApp.dll"]

我这样修改了它:

FROM mcr.microsoft.com/dotnet/core/sdk:3.0-buster AS build
ENV DOTNET_USE_POLLING_FILE_WATCHER 1
WORKDIR /src
EXPOSE 80
EXPOSE 443
COPY ["DockerTestApp/DockerTestApp.csproj", "DockerTestApp/"]
RUN dotnet restore "DockerTestApp/DockerTestApp.csproj"
ENTRYPOINT ["dotnet", "watch", "run"] 

以 dotnet watch run 开头的容器，但未检测到任何文件更改，也不会触发重建.

The container started with dotnet watch run but any file change isn't detected and the rebuild is not triggered.

我是否必须将代码目录中的卷挂载到容器上才能正常工作?

Should I have to mount a volume from my code directory to the container in order to make it work?

谢谢.

更新

使用此Dokerfile

with this Dokerfile

FROM mcr.microsoft.com/dotnet/core/sdk:3.0

ENV DOTNET_USE_POLLING_FILE_WATCHER 1

WORKDIR /app
COPY . .
ENTRYPOINT dotnet watch run  --urls=https://+:5001 --project DocketTestApp.csproj

和这个docker-compose.yml

and this docker-compose.yml

version: '3.4'

services:
  dotnet-watch-docker-example:
    container_name: dotnet_watch_docker_example
    image: giuseppeterrasi/dotnet-watch-docker-example
    build:
      context: ./DocketTestApp/
    ports:
      - 5001:5001
    volumes:
      - './DocketTestApp/:/app/'
    depends_on: 
      - db
  db:
    image: mysql
    restart: always
    ports:
        - "3306:3306"
    environment:
      MYSQL_ROOT_PASSWORD: testPassword
      MYSQL_DATABASE: testDB
      MYSQL_USER: testUser
      MYSQL_PASSWORD: test

它可以工作，但是如果我添加了一个DbContext，则在容器启动时Visual Studio会错过Entity Framework引用.如果我停止容器并重新加载Visual Studio，一切正常.

It works, but if I add a DbContext, Visual Studio misses the Entity Framework reference if the container is started. If I stop the container and reload Visual Studio everything is ok.

为什么?

推荐答案

当您要在本地运行 dotnet watch run 时，可以省略使用自定义Dockerfile.

You can omit using a custom Dockerfile when you want to run dotnet watch run locally.

考虑以下 docker-compose.yml 文件:

version: '3.4'

services:
  dotnet-watch-docker-example:
    container_name: dotnet_watch_docker_example
    image: mcr.microsoft.com/dotnet/core/sdk:3.0
    ports:
      - 5001:5001
    volumes:
      - ./DockerTestApp:/app
    working_dir: /app
    command: dotnet watch run

撰写文件并没有从基础dotnet sdk图像创建自定义图像，而是仅基于基础dotnet sdk图像启动了一个容器.然后，它创建一个卷，该卷将包含您的项目的本地目录映射到容器内的目录/app.然后将容器内的工作目录设置为/app，最后，在容器内运行dotnet watch run命令.

Instead of creating a custom image from the base dotnet sdk image, the compose file simply starts a container based on the base dotnet sdk image. It then creates a volume that maps the local directory containing your project to the directory /app inside the container. It then sets the working directory inside the container to /app, and lastly, it runs the dotnet watch run command inside the container.

要解决有关实体框架参考的问题，请在项目目录中添加以下 Directory.Build.props 文件.该文件指示MSBUILD根据执行环境将/bin和/obj文件放置在不同的目录(容器/本地)中.这样，就不会出现冲突.

To fix your problem with the Entity framework reference, add the following Directory.Build.props file inside the project directory. This file instructs MSBUILD to place /bin and /obj files in different directories (container/local) dependent upon the executing environment. This way, no conflicts emerge.

<Project>
    <PropertyGroup>
        <DefaultItemExcludes>$(DefaultItemExcludes);$(MSBuildProjectDirectory)/obj/**/*</DefaultItemExcludes>
        <DefaultItemExcludes>$(DefaultItemExcludes);$(MSBuildProjectDirectory)/bin/**/*</DefaultItemExcludes>
    </PropertyGroup>
    <PropertyGroup Condition="'$(DOTNET_RUNNING_IN_CONTAINER)' == 'true'">
        <BaseIntermediateOutputPath>$(MSBuildProjectDirectory)/obj/container/</BaseIntermediateOutputPath>
        <BaseOutputPath>$(MSBuildProjectDirectory)/bin/container/</BaseOutputPath>
    </PropertyGroup>
    <PropertyGroup Condition="'$(DOTNET_RUNNING_IN_CONTAINER)' != 'true'">
        <BaseIntermediateOutputPath>$(MSBuildProjectDirectory)/obj/local/</BaseIntermediateOutputPath>
        <BaseOutputPath>$(MSBuildProjectDirectory)/bin/local/</BaseOutputPath>
    </PropertyGroup>
</Project>

这篇关于如何使用"dotnet watch run"使用.Net Core 3，Visual Studio 2019和Docker的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！