src/BuildingBlocks/WebHostCustomization/WebHost.Customization/WebHostExtensions.cs

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using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Polly;
using System;
using System.Data.SqlClient;

namespace Microsoft.AspNetCore.Hosting
{
    public static class IWebHostExtensions
    {
        public static bool IsInKubernetes(this IWebHost webHost)
        {
            var cfg = webHost.Services.GetService<IConfiguration>();
            var orchestratorType = cfg.GetValue<string>("OrchestratorType");
            return orchestratorType?.ToUpper() == "K8S";
        }

        public static IWebHost MigrateDbContext<TContext>(this IWebHost webHost, Action<TContext, IServiceProvider> seeder) where TContext : DbContext
        {
            var underK8s = webHost.IsInKubernetes();

            using var scope = webHost.Services.CreateScope();
            var services = scope.ServiceProvider;
            var logger = services.GetRequiredService<ILogger<TContext>>();
            var context = services.GetService<TContext>();

            try
            {
                logger.LogInformation("Migrating database associated with context {DbContextName}", typeof(TContext).Name);

                if (underK8s)
                {
                    InvokeSeeder(seeder, context, services);
                }
                else
                {
                    var retries = 10;
                    var retry = Policy.Handle<SqlException>()
                        .WaitAndRetry(
                            retryCount: retries,
                            sleepDurationProvider: retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)),
                            onRetry: (exception, timeSpan, retry, ctx) =>
                            {
                                logger.LogWarning(exception, "[{prefix}] Exception {ExceptionType} with message {Message} detected on attempt {retry} of {retries}", nameof(TContext), exception.GetType().Name, exception.Message, retry, retries);
                            });

                    //if the sql server container is not created on run docker compose this
                    //migration can't fail for network related exception. The retry options for DbContext only 
                    //apply to transient exceptions
                    // Note that this is NOT applied when running some orchestrators (let the orchestrator to recreate the failing service)
                    retry.Execute(() => InvokeSeeder(seeder, context, services));
                }

                logger.LogInformation("Migrated database associated with context {DbContextName}", typeof(TContext).Name);
            }
            catch (Exception ex)
            {
                logger.LogError(ex, "An error occurred while migrating the database used on context {DbContextName}", typeof(TContext).Name);