有没有办法从已发布的DLL运行EF Core RC2工具？

我最终在一个项目中遇到了同样的问题，但是由于多种原因，我不希望迁移在应用程序启动时自动运行。

为了解决这个问题，我更新Program.cs了两个参数（下面列出了完整的代码）

• --ef-migrate，以应用所有待处理的迁移，以及
• --ef-migrate-check，以验证是否已应用所有迁移

如果存在参数，则将应用EF操作并退出程序，否则将启动Web应用程序。

请注意，它取决于Microsoft.Extensions.CommandLineUtils软件包，以简化命令行解析。

对于octopus部署，一个人可以将程序包两次发布到不同的位置-一个用于运行迁移，另一个用于虚拟主机。在我们的例子中，我们添加了一个“ post deploy powershell脚本”，其中包含以下内容：

$env:ASPNETCORE_ENVIRONMENT="#{Octopus.Environment.Name}"
dotnet example-app.dll --ef-migrate

在docker上下文中，它也可以完美地工作

docker run -it "example-app-container" dotnet example-app.dll --ef-migrate

完整的Program.cs，不包括名称空间和使用方法：

//Remember to run: dotnet add package Microsoft.Extensions.CommandLineUtils
public class Program
{
    public static void Main(string[] args)
    {
        var commandLineApplication = new CommandLineApplication(false);
        var doMigrate = commandLineApplication.Option(
            "--ef-migrate",
            "Apply entity framework migrations and exit",
            CommandOptionType.NoValue);
        var verifyMigrate = commandLineApplication.Option(
            "--ef-migrate-check",
            "Check the status of entity framework migrations",
            CommandOptionType.NoValue);
        commandLineApplication.HelpOption("-? | -h | --help");
        commandLineApplication.OnExecute(() =>
        {
            ExecuteApp(args, doMigrate, verifyMigrate);
            return 0;
        });
        commandLineApplication.Execute(args);
    }

    private static void ExecuteApp(string[] args, CommandOption doMigrate, CommandOption verifyMigrate)
    {
        Console.WriteLine("Loading web host");
        //
        // Please note that this webHostBuilder below is from an older 
        // dotnet core version. Newer dotnet cores have a simplified version
        // Use that instead and just take the command line parsing stuff with you
        var webHost = new WebHostBuilder()
            .UseKestrel()
            .UseContentRoot(Directory.GetCurrentDirectory())
            .UseIISIntegration()
            .UseStartup<Startup>()
            .Build();

        if (verifyMigrate.HasValue() && doMigrate.HasValue())
        {
            Console.WriteLine("ef-migrate and ef-migrate-check are mutually exclusive, select one, and try again");
            Environment.Exit(2);
        }

        if (verifyMigrate.HasValue())
        {
            Console.WriteLine("Validating status of Entity Framework migrations");
            using (var serviceScope = webHost.Services.GetRequiredService<IServiceScopeFactory>().CreateScope())
            { 
                using (var context = serviceScope.ServiceProvider.GetService<DatabaseContext>())
                {
                    var pendingMigrations = context.Database.GetPendingMigrations();
                    var migrations = pendingMigrations as IList<string> ?? pendingMigrations.ToList();
                    if (!migrations.Any())
                    {
                        Console.WriteLine("No pending migratons");
                        Environment.Exit(0);
                    }

                    Console.WriteLine("Pending migratons {0}", migrations.Count());
                    foreach (var migration in migrations)
                    {
                        Console.WriteLine($"\t{migration}");
                    }

                    Environment.Exit(3);
                }
            }
        }

        if (doMigrate.HasValue())
        {
            Console.WriteLine("Applyting Entity Framework migrations");
            using (var serviceScope = webHost.Services.GetRequiredService<IServiceScopeFactory>().CreateScope())
            {
                using (var context = serviceScope.ServiceProvider.GetService<DatabaseContext>())
                {
                    context.Database.Migrate();
                    Console.WriteLine("All done, closing app");
                    Environment.Exit(0);
                }
            }
        }

        // no flags provided, so just run the webhost
        webHost.Run();
    }
}