MySQL Pomelo Entity Framework Core integration

MySQL is an open-source Relational Database Management System (RDBMS) that uses Structured Query Language (SQL) to manage and manipulate data. It’s employed in a many different environments, from small projects to large-scale enterprise systems and it’s a popular choice to host data that underpins microservices in a cloud-native application. The Aspire Pomelo MySQL Entity Framework Core integration enables you to connect to existing MySQL databases or create new instances from .NET with the mysql container image.

Hosting integration

The MySQL hosting integration models the server as the MySqlServerResource type and the database as the MySqlDatabaseResource type. To access these types and APIs, add the 📦 Aspire.Hosting.MySql NuGet package in your AppHost project:

Aspire CLI

Aspire CLI — Ajouter le package Aspire.Hosting.MySql

aspire add mysql

La CLI Aspire est interactive ; choisissez le résultat approprié lorsque demandé :

Aspire CLI — Exemple de sortie

Select an integration to add:

> mysql (Aspire.Hosting.MySql)
> Other results listed as selectable options...

Note

S'il n'y a qu'un seul résultat, il est sélectionné automatiquement. Vous devez quand même confirmer la version.

apphost.cs (C# file-based app)

C# — AppHost.cs

#:package Aspire.Hosting.MySql@*

PackageReference (*.csproj)

XML — Ajouter la référence de package Aspire.Hosting.MySql

<PackageReference Include="Aspire.Hosting.MySql" Version="*" />

Add MySQL server resource and database resource

In your AppHost project, call AddMySql to add and return a MySQL resource builder. Chain a call to the returned resource builder to AddDatabase, to add a MySQL database resource:

C# — AppHost.cs

var builder = DistributedApplication.CreateBuilder(args);

var mysql = builder.AddMySql("mysql")
    .WithLifetime(ContainerLifetime.Persistent);

var mysqldb = mysql.AddDatabase("mysqldb");

var myService = builder.AddProject<Projects.ExampleProject>()
    .WithReference(mysqldb)
    .WaitFor(mysqldb);

Note

The MySQL container is slow to start, so it’s best to use a persistent lifetime to avoid unnecessary restarts. For more information, see Container resource lifetime.

When Aspire adds a container image to the AppHost, it creates a new MySQL instance on your local machine. The MySQL resource includes default credentials with a username of root and a random password generated using the default password parameter.

When the AppHost runs, the password is stored in the AppHost’s secret store in the Parameters section:

{
  "Parameters:mysql-password": "<THE_GENERATED_PASSWORD>"
}

The WithReference method configures a connection in the ExampleProject named mysqldb.

Astuce

If you’d rather connect to an existing MySQL server, call AddConnectionString instead. For more information, see Reference existing resources.

Add a MySQL resource with a data volume

To add a data volume to the MySQL resource, call the WithDataVolume method on the MySQL resource:

C# — AppHost.cs

var builder = DistributedApplication.CreateBuilder(args);

var mysql = builder.AddMySql("mysql")
    .WithDataVolume();

var mysqldb = mysql.AddDatabase("mysqldb");

var myService = builder.AddProject<Projects.ExampleProject>()
    .WithReference(mysqldb)
    .WaitFor(mysqldb);

The data volume is used to persist the MySQL server data outside the lifecycle of its container. The data volume is mounted at the /var/lib/mysql path in the MySQL container and when a name parameter isn’t provided, the name is generated at random. For more information on data volumes and details on why they’re preferred over bind mounts, see Docker docs: Volumes.

Attention

The password is stored in the data volume. When using a data volume and if the password changes, it will not work until you delete the volume.

Danger

Some database integrations, including the MySQL integration, can’t successfully use data volumes after deployment to Azure Container Apps (ACA). This is because ACA uses Server Message Block (SMB) to connect containers to data volumes, and some systems can’t use this connection. In the Aspire Dashboard, a database affected by this issue has a status of Activating or Activation Failed but is never listed as Running.

You can resolve the problem by deploying to a Kubernetes cluster, such as Azure Kubernetes Services (AKS). For more information, see Deploy your first Aspire app.

Add a MySQL resource with a data bind mount

To add a data bind mount to the MySQL resource, call the WithDataBindMount method:

C# — AppHost.cs

var builder = DistributedApplication.CreateBuilder(args);

var mysql = builder.AddMySql("mysql")
    .WithDataBindMount(source: @"C:\MySql\Data");

var mysqldb = mysql.AddDatabase("mysqldb");

var myService = builder.AddProject<Projects.ExampleProject>()
    .WithReference(mysqldb)
    .WaitFor(mysqldb);

Note

Data bind mounts have limited functionality compared to volumes, and when you use a bind mount, a file or directory on the host machine is mounted into a container.

Data bind mounts rely on the host machine’s filesystem to persist the MySQL data across container restarts. For more information on data bind mounts, see Docker docs: Bind mounts.

Add MySQL resource with parameters

When you want to provide a root MySQL password explicitly, you can pass it as a parameter:

C# — AppHost.cs

var builder = DistributedApplication.CreateBuilder(args);

var password = builder.AddParameter("password", secret: true);

var mysql = builder.AddMySql("mysql", password)
    .WithLifetime(ContainerLifetime.Persistent);

var mysqldb = mysql.AddDatabase("mysqldb");

var myService = builder.AddProject<Projects.ExampleProject>()
    .WithReference(mysqldb)
    .WaitFor(mysqldb);

For more information, see External parameters.

Add a PhpMyAdmin resource

phpMyAdmin is a popular web-based administration tool for MySQL. To use phpMyAdmin within your Aspire solution, call the WithPhpMyAdmin method. This method adds a new container resource that hosts phpMyAdmin and connects it to the MySQL container:

C# — AppHost.cs

var builder = DistributedApplication.CreateBuilder(args);

var mysql = builder.AddMySql("mysql")
    .WithPhpMyAdmin();

var mysqldb = mysql.AddDatabase("mysqldb");

var myService = builder.AddProject<Projects.ExampleProject>()
    .WithReference(mysqldb)
    .WaitFor(mysqldb);

When you run the solution, the Aspire dashboard displays the phpMyAdmin resources with an endpoint. Select the link to the endpoint to view phpMyAdmin in a new browser tab.

Hosting integration health checks

The MySQL hosting integration automatically adds a health check for the MySQL resource. The health check verifies that the MySQL server is running and that a connection can be established to it.

The hosting integration relies on the 📦 AspNetCore.HealthChecks.MySql NuGet package.

Client integration

To get started with the Aspire MySQL database integration, install the 📦 Aspire.MySqlConnector NuGet package in the client-consuming project, that is, the project for the application that uses the MySQL client. The MySQL client integration registers a MySqlConnector.MySqlDataSource instance that you can use to interact with the MySQL server.

.NET CLI

.NET CLI — Add Aspire.MySqlConnector package

dotnet add package Aspire.MySqlConnector

Program.cs (C# file-based app)

Program.cs

#:package Aspire.MySqlConnector@*

PackageReference (*.csproj)

XML — Add Aspire.MySqlConnector package reference

<PackageReference Include="Aspire.MySqlConnector" Version="*" />

Add a MySQL data source

In the Program.cs file of your client-consuming project, call the AddMySqlDataSource extension method to register a MySqlDataSource for use via the dependency injection container. The method takes a connectionName parameter.

builder.AddMySqlDataSource(connectionName: "mysqldb");

Tip

The connectionName parameter must match the name used when adding the MySQL database resource in the AppHost project. In other words, when you call AddDatabase and provide a name of mysqldb that same name should be used when calling AddMySqlDataSource. For more information, see Add MySQL server resource and database resource.

You can then retrieve the MySqlConnector.MySqlDataSource instance using dependency injection. For example, to retrieve the data source from an example service:

public class ExampleService(MySqlDataSource dataSource)
{
    // Use dataSource...
}

For more information on dependency injection, see .NET dependency injection.

Add keyed MySQL data source

There might be situations where you want to register multiple MySqlDataSource instances with different connection names. To register keyed MySQL data sources, call the AddKeyedMySqlDataSource method:

builder.AddKeyedMySqlDataSource(name: "mainDb");
builder.AddKeyedMySqlDataSource(name: "loggingDb");

Caution

When using keyed services, it’s expected that your MySQL resource configured two named databases, one for the mainDb and one for the loggingDb.

Then you can retrieve the MySqlDataSource instances using dependency injection. For example, to retrieve the data source from an example service:

public class ExampleService(
    [FromKeyedServices("mainDb")] MySqlDataSource mainDataSource,
    [FromKeyedServices("loggingDb")] MySqlDataSource loggingDataSource)
{
    // Use data sources...
}

For more information on keyed services, see .NET dependency injection: Keyed services.

Configuration

The Aspire MySQL database integration provides multiple options to configure the connection based on the requirements and conventions of your project.

Use a connection string

When using a connection string from the ConnectionStrings configuration section, you can provide the name of the connection string when calling AddMySqlDataSource method:

C# — Program.cs

builder.AddMySqlDataSource(connectionName: "mysql");

Then the connection string is retrieved from the ConnectionStrings configuration section:

JSON — appsettings.json

{
  "ConnectionStrings": {
    "mysql": "Server=mysql;Database=mysqldb"
  }
}

For more information on how to format this connection string, see MySqlConnector: ConnectionString documentation.

Use configuration providers

The Aspire MySQL database integration supports Microsoft.Extensions.Configuration. It loads the MySqlConnectorSettings from configuration by using the Aspire:MySqlConnector key. The following snippet is an example of a appsettings.json file that configures some of the options:

JSON — appsettings.json

{
  "Aspire": {
    "MySqlConnector": {
      "ConnectionString": "YOUR_CONNECTIONSTRING",
      "DisableHealthChecks": true,
      "DisableTracing": true
    }
  }
}

For the complete MySQL integration JSON schema, see Aspire.MySqlConnector/ConfigurationSchema.json.

Use inline delegates

Also you can pass the Action<MySqlConnectorSettings> delegate to set up some or all the options inline, for example to disable health checks from code:

C# — Program.cs

builder.AddMySqlDataSource(
    "mysql",
    static settings => settings.DisableHealthChecks  = true);

Client integration health checks

By default, Aspire integrations enable health checks for all services. For more information, see Aspire integrations overview.

The Aspire MySQL database integration:

• Adds the health check when MySqlConnectorSettings.DisableHealthChecks is false, which verifies that a connection can be made and commands can be run against the MySQL database.
• Integrates with the /health HTTP endpoint, which specifies all registered health checks must pass for app to be considered ready to accept traffic.

Observability and telemetry

Aspire integrations automatically set up Logging, Tracing, and Metrics configurations.

Logging

The Aspire MySQL integration uses the following log categories:

• MySqlConnector.ConnectionPool
• MySqlConnector.MySqlBulkCopy
• MySqlConnector.MySqlCommand
• MySqlConnector.MySqlConnection
• MySqlConnector.MySqlDataSource

Tracing

The Aspire MySQL integration emits the following tracing activities using OpenTelemetry:

• MySqlConnector

Metrics

The Aspire MySQL integration will emit the following metrics using OpenTelemetry:

• MySqlConnector
  • db.client.connections.create_time
  • db.client.connections.use_time
  • db.client.connections.wait_time
  • db.client.connections.idle.max
  • db.client.connections.idle.min
  • db.client.connections.max
  • db.client.connections.pending_requests
  • db.client.connections.timeouts
  • db.client.connections.usage

See also

• MySQL database
• Aspire database containers sample
• Aspire integrations
• Aspire GitHub repo