如何在Docker容器中发布ASP.NET Core应用程序？

Question

I would like to publish a .net application in Docker Containers using Visual Studio 2015.

However, at step: Publish. I didn't see Docker Containers.

I installed Docker Toolbox, VS2015 Tool for Docker.

Thanks for your helping.

Answer 1

I'm not aware of a GUI tool at the moment to publish Docker containers for .NET. Docker comes from the world of Linux, where much of the work is done on the command-line and manually editing config files. Here is the basic process you need to follow to get a .NET process running in a docker container.

HOSTING .NET CORE ON LINUX WITH DOCKER

Read this!

General Docker Process

1. Setup Docker or Docker Toolbox on Windows or Linux (VM running on Virtualbox on your computer is fine for development)
2. Write a .dockerfile defining your image
3. Get Web API running in a container using docker commands

Number 1 I will leave you to follow the instruction for your platform easily found on the Docker website.

Write a dockerfile

Something like this, to start with:

    # Import the appropriate base container supplied by Microsoft
    FROM microsoft/aspnetcore:1.1.0
    # Name your process
    LABEL Name=mercury.docker.core-api Version=1.1.0 
    # Maps a folder on the host machine into the container, naming it SOURCE
    ARG source=./app
    # Creates a folder in the container and makes it the woring folder
    WORKDIR /app
    # Copies you application binaries from where you have put them (see next section) into the container
    COPY $source .
    EXPOSE 80
    ENTRYPOINT dotnet <you-main-app-file>.dll

Get Web API running in a container

Steps:

1. Build and publish your application for the appropriate host environment (windows, ubuntu etc)
2. Copy the pubished binaries to an \\app folder below the folder where your dockerfile is located.
3. Go to the Docker command-line, build and run the container

Specify the environments you want to target in your project.json file, and make sure you build and publish your project for the correct environment. For example, we are targeting the containers to run on Ubuntu, so we need to build and publish our binaries for that platform (currently ubuntu.14.04-x64 ). This does not work in Visual Studio 2015 Update 3 at this stage, so use the command line. In your project home directory:

dotnet build -r ubuntu.14.04-x64 --build-profile --configuration Release

dotnet publish -r ubuntu.14.04-x64 --configuration Release -o ./bin/Release/Publish

The required binaries are now in the ./bin/Release/Publish folder. The Dockerfile currently requires them in an /app sub-folder of the directory the Dockerfile is in, so

• copy the published files into your /app folder
• make sure that a suitable copy of the appsettings.json is prsesent

then in your Docker Quickstart Terminal windows (if using Docker Toolbox, which you seem to be), or the Ubuntu command line run, CD to the folder where your dockerfile is and run:

docker build -t <name_you_want_to_use_for_your_image> .

docker run -d -p 5500:80 -t <name_you_want_to_use_for_your_image>

Now test the API, using the IP address of the docker-machine as returned by docker-machine ip default :

curl http://<ip-address>:5500/<path appropriate for your api>>

This should return the JSON expected.