如何在数字海洋上将 aspnetcore 应用程序部署到 ubuntu

Question

在将我的 asp.net 核心 2.1 应用程序发布到 ubuntu 服务器上的 Digital Ocean 后，如果我在其他服务器中输入服务器 Ip 以在浏览器中打开应用程序，我收到此错误：

Service Unavailable 由于维护停机或容量问题，服务器暂时无法为您的请求提供服务。 请稍后再试。

Server_IP 端口 80 上的 Apache/version (Ubuntu) 服务器

从这条线：

Microsoft.AspNetCore.Identity.UserManager`1.FindByNameAsync(String userName)
at App_name.Data.ApplicationDbContext.CreateAdminAccount(IServiceProvider serviceProvider, IConfiguration configuration) in Data\ApplicationDbContext.cs:line

当我在本地午餐应用程序时，我检查是否不存在用户，然后 CreateAdminAccount 创建一个管理员用户。

确保应用程序在其他应用程序午餐之前无法进行任何迁移以创建管理员用户。

我想知道如何在应用程序启动时将迁移应用到数据库。

如果我检查应用程序日志，我也会收到此错误：

at System.Net.Sockets.Socket.BeginConnectEx(EndPoint remoteEP, Boolean flowContext, AsyncCallback callback, Object state)
at System.Net.Sockets.Socket.UnsafeBeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state, Boolean flowContext)
at System.Net.Sockets.Socket.BeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state)
at System.Threading.Tasks.TaskFactory1.FromAsyncImpl[TArg1](Func4 beginMethod, Func2 endFunction, Action1 endAction, TArg1 arg1, Object state, TaskCreationOptions creationOptions)
at Npgsql.NpgsqlConnector.ConnectAsync(NpgsqlTimeout timeout, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnector.RawOpen(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.AllocateLong(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnection.<>cDisplayClass32_0.<<Open>gOpenLong|0>d.MoveNext()
— End of stack trace from previous location where exception was thrown —
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnectionAsync(Boolean errorsExpected, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken, Boolean errorsExpected)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable1.AsyncEnumerator.BufferlessMoveNext(DbContext _, Boolean buffer, CancellationToken cancellationToken)
at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.NpgsqlExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func4 operation, Func4 verifySucceeded, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable1.AsyncEnumerator.MoveNext(CancellationToken cancellationToken)
at System.Linq.AsyncEnumerable.FirstOrDefault[TSource](IAsyncEnumerable1 source, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider.TaskResultAsyncEnumerable1.Enumerator.MoveNext(CancellationToken cancellationToken)
at System.Linq.AsyncEnumerable.SelectEnumerableAsyncIterator2.MoveNextCore(CancellationToken cancellationToken)
at System.Linq.AsyncEnumerable.AsyncIterator1.MoveNext(CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider.ExceptionInterceptor1.EnumeratorExceptionInterceptor.MoveNext(CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteSingletonAsyncQuery[TResult](QueryContext queryContext, Func2 compiledQuery, IDiagnosticsLogger1 logger, Type contextType)
at Microsoft.AspNetCore.Identity.UserManager1.FindByNameAsync(String userName)
at Appname.Data.ApplicationDbContext.CreateAdminAccount(IServiceProvider serviceProvider, IConfiguration configuration) in Data\ApplicationDbContext.cs:line 94
— End of inner exception stack trace —
at System.Threading.Tasks.Task.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
at Presscode.Startup.Configure(IApplicationBuilder app)
— End of stack trace from previous location where exception was thrown —
at Microsoft.AspNetCore.Hosting.ConventionBasedStartup.Configure(IApplicationBuilder app)
at Microsoft.AspNetCore.Hosting.Internal.AutoRequestServicesStartupFilter.<>cDisplayClass0_0.<Configure>b0(IApplicationBuilder builder)
at Microsoft.AspNetCore.Hosting.Internal.WebHost.BuildApplication()
—> (Inner Exception #0) System.Net.Sockets.SocketException (111): Connection refused
at System.Net.Sockets.Socket.BeginConnectEx(EndPoint remoteEP, Boolean flowContext, AsyncCallback callback, Object state)
at System.Net.Sockets.Socket.UnsafeBeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state, Boolean flowContext)
at System.Net.Sockets.Socket.BeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state)
at System.Threading.Tasks.TaskFactory1.FromAsyncImpl[TArg1](Func4 beginMethod, Func2 endFunction, Action1 endAction, TArg1 arg1, Object state, TaskCreationOptions creationOptions)
at Npgsql.NpgsqlConnector.ConnectAsync(NpgsqlTimeout timeout, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnector.RawOpen(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.ConnectorPool.AllocateLong(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken)
at Npgsql.NpgsqlConnection.<>cDisplayClass32_0.<<Open>gOpenLong|0>d.MoveNext()
— End of stack trace from previous location where exception was thrown —
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnectionAsync(Boolean errorsExpected, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken, Boolean errorsExpected)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable1.AsyncEnumerator.BufferlessMoveNext(DbContext _, Boolean buffer, CancellationToken cancellationToken)
at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.NpgsqlExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func4 operation, Func4 verifySucceeded, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncQueryingEnumerable1.AsyncEnumerator.MoveNext(CancellationToken cancellationToken)
at System.Linq.AsyncEnumerable.FirstOrDefault[TSource](IAsyncEnumerable1 source, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider.TaskResultAsyncEnumerable1.Enumerator.MoveNext(CancellationToken cancellationToken)
at System.Linq.AsyncEnumerable.SelectEnumerableAsyncIterator2.MoveNextCore(CancellationToken cancellationToken)
at System.Linq.AsyncEnumerable.AsyncIterator1.MoveNext(CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.AsyncLinqOperatorProvider.ExceptionInterceptor1.EnumeratorExceptionInterceptor.MoveNext(CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteSingletonAsyncQuery[TResult](QueryContext queryContext, Func2 compiledQuery, IDiagnosticsLogger1 logger, Type contextType)
at Microsoft.AspNetCore.Identity.UserManager1.FindByNameAsync(String userName)
at AppName.Data.ApplicationDbContext.CreateAdminAccount(IServiceProvider serviceProvider, IConfiguration configuration) in Data\ApplicationDbContext.cs:line 94<—```