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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Diagnostics.CodeAnalysis;
using Aspire;
using Aspire.Pomelo.EntityFrameworkCore.MySql;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Storage;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using MySqlConnector;
using MySqlConnector.Logging;
using Polly;
using Polly.Registry;
using Polly.Retry;
using Pomelo.EntityFrameworkCore.MySql.Infrastructure.Internal;
using Pomelo.EntityFrameworkCore.MySql.Storage.Internal;
namespace Microsoft.Extensions.Hosting;
/// <summary>
/// Provides extension methods for registering a MySQL database context in an Aspire application.
/// </summary>
public static partial class AspireEFMySqlExtensions
{
private const string DefaultConfigSectionName = "Aspire:Pomelo:EntityFrameworkCore:MySql";
private const DynamicallyAccessedMemberTypes RequiredByEF = DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors | DynamicallyAccessedMemberTypes.PublicProperties;
/// <summary>
/// Registers the given <see cref="DbContext" /> as a service in the services provided by the <paramref name="builder"/>.
/// Enables db context pooling, retries, corresponding health check, logging and telemetry.
/// </summary>
/// <typeparam name="TContext">The <see cref="DbContext" /> that needs to be registered.</typeparam>
/// <param name="builder">The <see cref="IHostApplicationBuilder" /> to read config from and add services to.</param>
/// <param name="connectionName">A name used to retrieve the connection string from the ConnectionStrings configuration section.</param>
/// <param name="configureSettings">An optional delegate that can be used for customizing options. It's invoked after the settings are read from the configuration.</param>
/// <param name="configureDbContextOptions">An optional delegate to configure the <see cref="DbContextOptions"/> for the context.</param>
/// <remarks>
/// <para>
/// Reads the configuration from "Aspire:Pomelo:EntityFrameworkCore:MySql:{typeof(TContext).Name}" config section, or "Aspire:Pomelo:EntityFrameworkCore:MySql" if former does not exist.
/// </para>
/// <para>
/// The <see cref="DbContext.OnConfiguring" /> method can then be overridden to configure <see cref="DbContext" /> options.
/// </para>
/// </remarks>
/// <exception cref="ArgumentNullException">Thrown if mandatory <paramref name="builder"/> is null.</exception>
/// <exception cref="InvalidOperationException">Thrown when mandatory <see cref="PomeloEntityFrameworkCoreMySqlSettings.ConnectionString"/> is not provided.</exception>
public static void AddMySqlDbContext<[DynamicallyAccessedMembers(RequiredByEF)] TContext>(
this IHostApplicationBuilder builder,
string connectionName,
Action<PomeloEntityFrameworkCoreMySqlSettings>? configureSettings = null,
Action<DbContextOptionsBuilder>? configureDbContextOptions = null) where TContext : DbContext
{
ArgumentNullException.ThrowIfNull(builder);
builder.EnsureDbContextNotRegistered<TContext>();
var settings = builder.GetDbContextSettings<TContext, PomeloEntityFrameworkCoreMySqlSettings>(
DefaultConfigSectionName,
(settings, section) => section.Bind(settings)
);
if (builder.Configuration.GetConnectionString(connectionName) is string connectionString)
{
settings.ConnectionString = connectionString;
}
configureSettings?.Invoke(settings);
builder.Services.AddDbContextPool<TContext>(ConfigureDbContext);
const string resilienceKey = "Microsoft.Extensions.Hosting.AspireEFMySqlExtensions.ServerVersion";
builder.Services.AddResiliencePipeline(resilienceKey, static builder =>
{
// Values are taken from MySqlRetryingExecutionStrategy.MaxRetryCount and MaxRetryDelay.
builder.AddRetry(new RetryStrategyOptions
{
ShouldHandle = static args => args.Outcome is { Exception: MySqlException { IsTransient: true } }
? PredicateResult.True()
: PredicateResult.False(),
BackoffType = DelayBackoffType.Exponential,
MaxRetryAttempts = 6,
Delay = TimeSpan.FromSeconds(1),
MaxDelay = TimeSpan.FromSeconds(30),
});
});
ConfigureInstrumentation<TContext>(builder, settings);
void ConfigureDbContext(IServiceProvider serviceProvider, DbContextOptionsBuilder dbContextOptionsBuilder)
{
// use the legacy method of setting the ILoggerFactory because Pomelo EF Core doesn't use MySqlDataSource
if (serviceProvider.GetService<ILoggerFactory>() is { } loggerFactory)
{
MySqlConnectorLogManager.Provider = new MicrosoftExtensionsLoggingLoggerProvider(loggerFactory);
}
var connectionString = settings.ConnectionString ?? string.Empty;
ServerVersion serverVersion;
if (settings.ServerVersion is null)
{
ConnectionStringValidation.ValidateConnectionString(settings.ConnectionString, connectionName, DefaultConfigSectionName, $"{DefaultConfigSectionName}:{typeof(TContext).Name}", isEfDesignTime: EF.IsDesignTime);
var resiliencePipelineProvider = serviceProvider.GetRequiredService<ResiliencePipelineProvider<string>>();
var resiliencePipeline = resiliencePipelineProvider.GetPipeline(resilienceKey);
serverVersion = resiliencePipeline.Execute(static cs => ServerVersion.AutoDetect(cs), connectionString);
}
else
{
serverVersion = ServerVersion.Parse(settings.ServerVersion);
}
var builder = dbContextOptionsBuilder.UseMySql(connectionString, serverVersion, builder =>
{
// delay validating the ConnectionString until the DbContext is configured. This ensures an exception doesn't happen until a Logger is established.
ConnectionStringValidation.ValidateConnectionString(settings.ConnectionString, connectionName, DefaultConfigSectionName, $"{DefaultConfigSectionName}:{typeof(TContext).Name}", isEfDesignTime: EF.IsDesignTime);
// Resiliency:
// 1. Connection resiliency automatically retries failed database commands: https://github.com/PomeloFoundation/Pomelo.EntityFrameworkCore.MySql/wiki/Configuration-Options#enableretryonfailure
if (!settings.DisableRetry)
{
builder.EnableRetryOnFailure();
}
if (settings.CommandTimeout.HasValue)
{
builder.CommandTimeout(settings.CommandTimeout);
}
});
configureDbContextOptions?.Invoke(dbContextOptionsBuilder);
}
}
/// <summary>
/// Configures retries, health check, logging and telemetry for the <see cref="DbContext" />.
/// </summary>
/// <exception cref="ArgumentNullException">Thrown if mandatory <paramref name="builder"/> is null.</exception>
/// <exception cref="InvalidOperationException">Thrown when mandatory <see cref="DbContext"/> is not registered in DI.</exception>
public static void EnrichMySqlDbContext<[DynamicallyAccessedMembers(RequiredByEF)] TContext>(
this IHostApplicationBuilder builder,
Action<PomeloEntityFrameworkCoreMySqlSettings>? configureSettings = null) where TContext : DbContext
{
ArgumentNullException.ThrowIfNull(builder);
var settings = builder.GetDbContextSettings<TContext, PomeloEntityFrameworkCoreMySqlSettings>(
DefaultConfigSectionName,
(settings, section) => section.Bind(settings)
);
configureSettings?.Invoke(settings);
ConfigureRetry();
ConfigureInstrumentation<TContext>(builder, settings);
void ConfigureRetry()
{
#pragma warning disable EF1001 // Internal EF Core API usage.
if (!settings.DisableRetry || settings.CommandTimeout.HasValue)
{
builder.PatchServiceDescriptor<TContext>(optionsBuilder =>
{
if (optionsBuilder.Options.FindExtension<MySqlOptionsExtension>() is not MySqlOptionsExtension extension ||
extension.ServerVersion is not ServerVersion serverVersion)
{
throw new InvalidOperationException($"A DbContextOptions<{typeof(TContext).Name}> was not found. Please ensure 'ServerVersion' was configured.");
}
optionsBuilder.UseMySql(serverVersion, options =>
{
var extension = optionsBuilder.Options.FindExtension<MySqlOptionsExtension>();
if (!settings.DisableRetry)
{
var executionStrategy = extension?.ExecutionStrategyFactory?.Invoke(new ExecutionStrategyDependencies(null!, optionsBuilder.Options, null!));
if (executionStrategy != null)
{
if (executionStrategy is MySqlRetryingExecutionStrategy)
{
// Keep custom Retry strategy.
// Any sub-class of MySqlRetryingExecutionStrategy is a valid retry strategy
// which shouldn't be replaced even with DisableRetry == false
}
else if (executionStrategy.GetType() != typeof(MySqlExecutionStrategy))
{
// Check MySqlExecutionStrategy specifically (no 'is'), any sub-class is treated as a custom strategy.
throw new InvalidOperationException($"{nameof(PomeloEntityFrameworkCoreMySqlSettings)}.{nameof(PomeloEntityFrameworkCoreMySqlSettings.DisableRetry)} needs to be set when a custom Execution Strategy is configured.");
}
else
{
options.EnableRetryOnFailure();
}
}
else
{
options.EnableRetryOnFailure();
}
}
if (settings.CommandTimeout.HasValue)
{
if (extension != null &&
extension.CommandTimeout.HasValue &&
extension.CommandTimeout != settings.CommandTimeout)
{
throw new InvalidOperationException($"Conflicting values for 'CommandTimeout' were found in {nameof(PomeloEntityFrameworkCoreMySqlSettings)} and set in DbContextOptions<{typeof(TContext).Name}>.");
}
options.CommandTimeout(settings.CommandTimeout);
}
});
});
}
#pragma warning restore EF1001 // Internal EF Core API usage.
}
}
private static void ConfigureInstrumentation<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors | DynamicallyAccessedMemberTypes.NonPublicConstructors | DynamicallyAccessedMemberTypes.PublicProperties)] TContext>(IHostApplicationBuilder builder, PomeloEntityFrameworkCoreMySqlSettings settings) where TContext : DbContext
{
if (!settings.DisableHealthChecks)
{
// calling MapHealthChecks is the responsibility of the app, not Component
builder.TryAddHealthCheck(
name: typeof(TContext).Name,
static hcBuilder => hcBuilder.AddDbContextCheck<TContext>());
}
if (!settings.DisableTracing)
{
builder.Services.AddOpenTelemetry()
.WithTracing(tracerProviderBuilder =>
{
// add tracing from the underlying MySqlConnector ADO.NET library
tracerProviderBuilder.AddSource("MySqlConnector");
});
}
if (!settings.DisableMetrics)
{
builder.Services.AddOpenTelemetry()
.WithMetrics(meterProviderBuilder =>
{
// add metrics from the underlying MySqlConnector ADO.NET library
meterProviderBuilder.AddMeter("MySqlConnector");
});
}
}
}
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