How to Dockerize both ASP.NET Core 3.1 and MySQL Server in Windows containers?

Introduction

This article shows how to use MySQL in a Windows Docker container communicating with an ASP.NET Core 3.1 web app running on the host computer. First of all you have to know,

What is Docker?

Docker is a set of platform as a service products that uses OS-level virtualization to deliver software in packages called containers.Containers are isolated from one another and bundle their own software, libraries and configuration files; they can communicate with each other through well-defined channels

What is ASP.NET Core?

ASP.NET Core is a free and open-source of web framework, and higher performance than ASP.NET, developed by Microsoft and the community. It is a modular framework that runs on both the full .NET Framework, on Windows, and the cross-platform .NET Core.

What is MySQL?

MySQL is an open source relational database.MySQL is cross platform which means it runs on a number of different platforms such as Windows, Linux, and Mac OS etc.

Dockerize both ASP.NET Core 3.1 and MySQL Server in Windows containers

This guide explains setting up a production-ready ASP.NET Core environment on Docker. Our Web Application can perform basic CRUD operations.

In this article, you will learn how to

1. How to Set Up Docker in your Windows 10
2. Create a simple ASP.NET Core Web Application which do CRUD Operations using Entity Framework(with My SQL Server)
3. Created MySQL and ASP.NET Core Web Application container in Docker on Windows Container
4. Hosted both ASP.NET Core 3.1 and MySQL Server Container in Docker

Required Tools

• Windows 10
• ASP.NET Core SDK 3.1
• Visual Studio
• VS Code
• Docker

Step 1 . Install Docker in Windows 10

Docker Desktop for Windows is the Community version of Docker for Microsoft Windows. You can download Docker Desktop for Windows from Docker Hub. Download Link It is a big file of 916 MB.

After downloading that-->

• Double-click Docker Desktop Installer.exe to run the installer.

• Follow the Install Wizard: accept the license, authorize the installer, and proceed with the install.Here is Ours' Configuration

• Click Finish to launch Docker.
• Docker starts automatically.
• Docker loads a “Welcome” window giving you tips and access to the Docker documentation

Docker Provides two Containers Linux and Windows . We will use Windows Container. We will use some experimental features. Experimental features are not ready for production. They are provided for test and evaluation in your sandbox environments. For that we will have to a little change in Docker. Firstly go to system tray.Then Press right buttor on Docker Logo Settings --> Docker Engine --> "experimental": true

Our Final Docker Engine

Our Docker is now Ready....!

Step 2. Create An ASP.NET Core Web App Using MySQL Database

• From the File menu, select New > Project.

• Select the ASP.NET Core Web Application template and click Next.

• Name the project WebAplicationMySQL and click Create.

• In the Create a new ASP.NET Core Web Application dialog, confirm that .NET Core and ASP.NET Core 3.1 are selected. Select the MVC template and click Create.

N.B. Unselect the configure for Https

Step 3: Adding Dependencies in ASP.NET Core

Before we start our project need a few dependencies. We will add them all by NuGet Package Manager.

The list of packages is below:

• Microsoft.EntityFrameworkCore
• Pomelo.EntityFrameworkCore.MySql
• Microsoft.EntityFrameworkCore.Tools
• Microsoft.EntityFrameworkCore.Design

I use Polemo provider instead Oracle provider (MySql.Data.EntityFrameworkCore) because Oracle’s connector doesn’t support EF migrations, also relationships there can be implemented only in Fluent.API. EF Tools I installed just for simplifying entering commands in Package Manager Console (Final Step of this story).

Step 4: Adding Models and Database Context

For start we need basic EF Models and DbContext. In this example I will create simple models with user and his pets. This example also will demonstrate auto-creation of relationships by Entity Framework. Firstly create a folder named Models,then create

StudentDetail.cs Model Class

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace WebAplicationMySQL.Models
{
    public class StudentDetail
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int ID { get; set; }

        [Required]
        [Column(TypeName = "nvarchar(100)")]
        public string Name { get; set; }

        [Required]
        [Column(TypeName = "varchar(11)")]
        public string Phone_Number { get; set; }

        [Required]
        [Column(TypeName = "varchar(10)")]
        public string Birth_Date { get; set; }
    }
}

Then Create DBContext file named StudentDetailContext.cs

using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace WebAplicationMySQL.Models
{
    public class StudentDetailContext : DbContext
    {
        public StudentDetailContext(DbContextOptions<StudentDetailContext> options) : base(options)
        {

        }
        public DbSet<StudentDetail> StudentDetails { get; set; }
        //Table Name StudentDetails
    }
}

Step 5 : Configure Dependency Injection

Make sure this three must be include in startup.cs class.

Let us configure our web application to use MySQL instead of SQLite. Open the Startup.cs file in your favorite editor and comment out (or delete) the following statement found in the ConfigureServices() method:

//services.AddDbContext<ApplicationDbContext>(options =>
//   options.UseSqlite(Configuration.GetConnectionString("DefaultConnection")));

Replace the above code with the following:

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            //instead of "localhost" you can use your IP address.
            //For getting you IP Address go to `cmd` ,then type 'ipconfig'
            var host = Configuration["DBHOST"] ?? "localhost";

            var port = Configuration["DBPORT"] ?? "3306";

            var password = Configuration["DBPASSWORD"] ?? "1234";


            //StudentDetailContext is Our DB Context Class
            services.AddDbContextPool<StudentDetailContext>(
                    options =>
                    {
                        options.UseMySql($"server={host};userid=root;pwd={password};"
                        + $"port={port};database=StudentDB");
                    });
            services.AddControllersWithViews();
        }

Three environment variables are used in the database connection string. These are: DBHOST, DBPORT and DBPASSWORD. If these environment variables are not found then they will take up default values: localhost, 3306 and 1234 respectively.

We can instruct our application to automatically process any outstanding Entity Framework migrations. This is done by adding the following argument to the Configure() method in Startup.cs:

StudentDetailContext context

This means that our Configure() method will have the following signature:

public void Configure(IApplicationBuilder app, IHostingEnvironment env, StudentDetailContext context)

Next, add the following code inside the Configure() method in Startup.cs right before app.UseRouting();

context.Database.Migrate();

Here is our Full Code,

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env, StudentDetailContext context)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }
            app.UseStaticFiles();

            context.Database.Migrate();
            app.UseRouting();

            app.UseAuthorization();
            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=StudentDetails}/{action=Index}/{id?}");
            });
        }

N.B. StudentDetailContext is ours' DB Context Class ,you wrote your own. You can see we changed our app.UseEndpoints() method. Just changed the Controlled name .Here StudentDetails is ours controller .

This is all you need to do in order to change the database configuration of our application so that it uses MySQL instead of SQLite.

Then create Controller Class. VS create it automatically. Following the steps below.

• Click right button of mouse and add controller class

• Select MVC Controller with views

Views in File Explorer...

s

• Select your Model class and our DB Context Class

Step 6 : Migrations

If you installed EF Tools as me, than you can just run next 2 commands in Package Manager Console:

open your Package Manager Console

Add-Migration <MigrationName>

Here is mine,

Add-Migration InitialCreate

If any problem in your Migration delete your previous migrations.

Remove-Migration

N.B. we don't need update Database command After a successful migration , when we Run this app,a table named StudentDetails in studentdb database

Step 7 : Run Our Web App in Locally

go to Package Manager then type

dotnet build
dotnet run

Your application will run into this ipaddress

localhost:5000

Home Page

Step 8 : Dockerfile for Running ASP.NET Core APP with My SQL Database

Now we need to start Docker . It is a heavy app,Visual Studio is also a heavy app.So that I prefer use VS Code for doing the rest. Close your Visual Studio and follow the instruction below for opening your project in VS Code. Open the folder where your project created.Then type cmd in topbar.

then type code . in cmd. Your project will open in VS Code

Our Project-->

We will generate the release version of the application by executing the following command from a terminal window in the root directory of your ASP.NET Core 3.1 project:

dotnet publish -o dist

We need to create a docker image that will contain the dotnet core 3.1 runtime. A suitable image for this purpose is: dotnet/core/aspnet:3.1-nanoserver-1903

Create a text file named Dockerfile and add to it the following content:

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-nanoserver-1903 AS base
COPY dist /app
WORKDIR /app
EXPOSE 80/tcp
ENTRYPOINT ["dotnet", "WebApplicationMySQL.dll"]

Above are instructions to create a Docker image that will contain our ASP.NET Core 3.1 application. I describe each line below:

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-nanoserver-1903 AS base

Base image dotnet/core/aspnet:3.1-nanoserver-1903 will be used

COPY dist /app

Contents of the dist directory on the host computer will be copied to directory /app in the container

WORKDIR /app	

The working directory in the container is /app

EXPOSE 80/tcp	

Port 80 will be exposed in the container

ENTRYPOINT ["dotnet", "WebApplicationMySQL.dll"]

The main ASP.NET Core 3.1 web application will be launched by executing dotnet WebApplicationMySQL.dll

We will next compose a docker yml file that orchestrates the entire system which involves two containers: a MySQL database server container and a container that holds our application. In the root folder of your application, create a text file named docker-compose.yml and add to it the following content:

version: "3.4"

volumes:
 datafiles:

services:
 db:
  image: mysql
  volumes:
    - datafiles:/var/lib/mysql
  restart: always
  environment:
    MYSQL_ROOT_PASSWORD: 1234
 mvc:
  build:
   context: .
   dockerfile: Dockerfile
  depends_on:
   - db
  ports:
   - "8888:80"
  restart: always
  environment:
    - DBHOST=db
    - ASPNETCORE_ENVIRONMENT=Development

N.B. Indentention is a Must in yml file Below is an explanation of what this file does.

We will be having two containers. Each container is considered to be a service. The first service is named db and will host MySQL. The second service is named mvc and will host our ASP.NET Core 3.1 web app.

The most current version of docker-compose is version 3.4. This is the first line in our docker-compose file.

• The MySQL Container

image: mysql will be used for the MySQL container.

A volume named datafiles is declared that will host MySQL data outside of the container. This ensures that even if the MySQL container is decommissioned, data will not be lost.

restart: always is so that if the container stops, it will be automatically restarted.

The root password will be secret when MySQL is configured. This is set by the MYSQL_ROOT_PASSWORD environment variable.

• The ASP.NET Core 3.1 Web Application Container

The container will be built using the instructions in the Dockerfile file and the context used is the current directory.

depends_on indicated that the web app relies on the MySQL container (db) to properly function.

Port 80 in the mvc container is mapped to port 8888 on the host computer.

Just like in the db container, restart: always is so that if the container stops, it will be automatically restarted.

The environment variables needed by the web app are:

- DBHOST pointing to the MySQL service and
- ASPNETCORE_ENVIRONMENT set to Development more. In reality, you should change this to Production one you determine that your web app container works as expected.

Open the terminal of VS Code. Then run this two command ,

docker-compose build

docker-compose up

Point your browser to http://localhost:8888/ and you should see the main web page.

Home Page

Our Edit Page,

After Adding One Row,

Now go to Docker . We will see our WebApplictionMySQL Image

Explore that image will we two containers as in the docker-compose.yml go to system tray.Then Press right button on Docker Logo.Then Dashboard

WebAplicationMySQL_mvc_1 container log

WebAplicationMySQL_db_1 container log

We also checks our containers though Windows Power Shell. Write this command

docker ps -a

To ensure that the database works properly, please enter a Student details here and check your database into Docker mysql container.

In my case, I checked them through this process.

docker ps -a
docker exec -it <your_Container_ID> bash
mysql -u root -p

our user was root and password is 1234 Then log in as root user

show database;
use Students;
show tables;
describe Studentdetails;
Select * from Studentdetails;

Normal SQL commands

StudentDetails Table

Full Code

Full Project Link