Quickstart: Compose and ASP.NET Core with SQL Server
読む時間の目安: 6 分
This quick-start guide demonstrates how to use Docker Engine on Linux and Docker Compose to set up and run the sample ASP.NET Core application using the .NET Core SDK image with the SQL Server on Linux image. You just need to have Docker Engine and Docker Compose installed on your platform of choice: Linux, Mac or Windows.
For this sample, we create a sample .NET Core Web Application using the
microsoft/dotnet:2.1-sdk
Docker image. After that, we create a Dockerfile
,
configure this app to use our SQL Server database, and then create a
docker-compose.yml
that defines the behavior of all of these components.
Note: This sample is made for Docker Engine on Linux. For Windows Containers, visit Docker Labs for Windows Containers.
-
Create a new directory for your application.
This directory is the context of your docker-compose project. For Docker Desktop for Windows and Docker Desktop for Mac, you need to set up file sharing for the volume that you need to map.
-
Within your directory, use the
dotnet:2.1-sdk
Docker image to generate a sample web application within the container under the/app
directory and into your host machine in the working directory:$ docker run -v ${PWD}:/app --workdir /app microsoft/dotnet:2.1-sdk dotnet new mvc --auth Individual
Note: If running in Docker Desktop for Windows, make sure to use Powershell or specify the absolute path of your app directory.
-
Create a
Dockerfile
within your app directory and add the following content:# syntax=docker/dockerfile:1 FROM microsoft/dotnet:2.1-sdk COPY . /app WORKDIR /app RUN ["dotnet", "restore"] RUN ["dotnet", "build"] EXPOSE 80/tcp RUN chmod +x ./entrypoint.sh CMD /bin/bash ./entrypoint.sh
This file defines how to build the web app image. It uses the .NET Core SDK image, maps the volume with the generated code, restores the dependencies, builds the project and exposes port 80. After that, it calls an
entrypoint
script that we create in the next step. -
The
Dockerfile
makes use of an entrypoint to your webapp Docker image. Create this script in a file calledentrypoint.sh
and paste the contents below.Note: Make sure to use UNIX line delimiters. The script doesn’t work if you use Windows-based delimiters (Carriage return and line feed).
#!/bin/bash set -e run_cmd="dotnet run --server.urls http://*:80" until dotnet ef database update; do >&2 echo "SQL Server is starting up" sleep 1 done >&2 echo "SQL Server is up - executing command" exec $run_cmd
This script restores the database after it starts up, and then runs the application. This allows some time for the SQL Server database image to start up.
-
Create a
docker-compose.yml
file. Write the following in the file, and make sure to replace the password in theSA_PASSWORD
environment variable underdb
below. This file defines the way the images interact as independent services.Note: The SQL Server container requires a secure password to startup: Minimum length 8 characters, including uppercase and lowercase letters, base 10 digits and/or non-alphanumeric symbols.
version: "3.9" services: web: build: . ports: - "8000:80" depends_on: - db db: image: "mcr.microsoft.com/mssql/server" environment: SA_PASSWORD: "Your_password123" ACCEPT_EULA: "Y"
This file defines the
web
anddb
micro-services, their relationship, the ports they are using, and their specific environment variables.Note: You may receive an error if you choose the wrong Compose file version. Be sure to choose a version that is compatible with your system.
-
Go to
Startup.cs
and locate the function calledConfigureServices
(Hint: it should be under line 42). Replace the entire function to use the following code (watch out for the brackets!).Note: Make sure to update the
Password
field in theconnection
variable below to the one you defined in thedocker-compose.yml
file.<...> public void ConfigureServices(IServiceCollection services) { // Database connection string. // Make sure to update the Password value below from "Your_password123" to your actual password. var connection = @"Server=db;Database=master;User=sa;Password=Your_password123;"; // This line uses 'UseSqlServer' in the 'options' parameter // with the connection string defined above. services.AddDbContext<ApplicationDbContext>( options => options.UseSqlServer(connection)); services.AddIdentity<ApplicationUser, IdentityRole>() .AddEntityFrameworkStores<ApplicationDbContext>() .AddDefaultTokenProviders(); services.AddMvc(); // Add application services. services.AddTransient<IEmailSender, AuthMessageSender>(); services.AddTransient<ISmsSender, AuthMessageSender>(); } <...>
-
Go to
app.csproj
. You see a line like:<PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="1.1.2" />
The generated project uses sqlite by default. To use SQL Server, add this line to
app.csproj
:<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.2" />
The Sqlite dependency was at version 1.1.2 at the time of this writing. Use the same version for the SQL Server dependency.
-
Ready! You can now run the
docker-compose build
command.$ docker-compose build
-
Make sure you allocate at least 2GB of memory to Docker Engine. Here is how to do it on Docker Desktop for Mac and Docker Desktop for Windows. This is necessary to run the SQL Server on Linux container.
-
Run the
docker-compose up
command. After a few seconds, you should be able to open localhost:8000 and see the ASP.NET core sample website. The application is listening on port 80 by default, but we mapped it to port 8000 in thedocker-compose.yml
.$ docker-compose up
Go ahead and try out the website! This sample uses the SQL Server database image in the back-end for authentication.
Ready! You now have an ASP.NET Core application running against SQL Server in Docker Compose! This sample made use of some of the most popular Microsoft products for Linux. To learn more about Windows Containers, check out Docker Labs for Windows Containers to try out .NET Framework and more SQL Server tutorials.
Next steps
- Build your app using SQL Server
- SQL Server on Docker Hub
- ASP.NET Core
- ASP.NET Core Docker image on DockerHub
More Compose documentation
- Docker Compose overview
- Install Docker Compose
- Getting Started with Docker Compose
- Docker Compose Command line reference
- Compose file reference
- Awesome Compose samples