Connect to SQL Server database from a docker container

Question

I have docker for windows installed on my machine. There is a console application targeting .net core 1.0.0 that tries to access a SQL Server database running on a different VM.

Answer 1

as in this answer

SQL Server instance string connection in Linux Docker

According to Saurabh Singh from Microsoft:

The Instance name support is available in v 1.1 of .Net Core. In v1.0 of .Net Core, Instance names are not supported on OS other than Windows.

So I don't think you can connect from .Net Core 1.0 running on Linux to an SQL Server using instance name.

Your choices seem to be:

don't use instance name
wait for .Net Core 1.1 (planned for "Fall 2016")
use pre-release version of .Net Core 1.1

Answer 2

Assumptions

• Microsoft SQL Server 2016
• Windows 10 Anniversary Update
• Windows Containers
• ASP.NET Core application

Add a SQL user to your SQL database.

• In MS SQL expand the database
• Right click on 'Security / Logins'
• Select 'New Login'
• Create a user name and password.
• Assign a 'Server Role(s)'...I used sysadmin since I'm just testing
• Under 'User Mapping' I added my new user to my database and used 'dbo' for schema.

Change SQL Authentication to allow SQL Server Authentication Mode

Right click on your database, select 'Properties / Security / Server Authentication / SQL Server and Windows Authentication Mode' radio button. Restart the MS SQL service.

Update your appsettings.json with your new user name and password

Example

"ConnectionStrings": {
        "DefaultConnection": "Server=YourServerName;Database=YourDatabaseName;MultipleActiveResultSets=true;User Id=UserNameYouJustAdded;Password=PassordYouJustCreated"
},

Make sure you remove Trusted_Connection=True.

Create a Docker file

My example Docker file

FROM microsoft/dotnet:nanoserver
ARG source=.
WORKDIR /app 
EXPOSE 5000 
EXPOSE 1433 
ENV ASPNETCORE_URLS http://+:5000 
COPY $source .

Publish Application

Running from the same location as the Docker file in an elevated PowerShell

dotnet publish

docker build bin\Debug\netcoreapp1.0\publish -t aspidserver

docker run -it  aspidserver cmd

I wanted to run the container and see the output as it was running in PowerShell.

Once the container was up and running in the container at the command prompt I kicked off my application.

dotnet nameOfApplication.dll

If everything went to plan one should be up and running.

Answer 3

You can run a docker container with network settings set to host. Such a container will share the network stack with the docker host and from the container point of view, localhost (or 127.0.0.1) will refer to the docker host.

docker run --net=host ... 

Then you should get the SQL Server database from inside the docker container as you do from your host.