C# Can'；t从运行在GCP云上的.net应用程序连接到postgres实例

我有一个应用程序在GCP云运行实例中运行，它使用映射在pgsql db上的EF核心，但由于某些原因，我无法连接到数据库

以下是用于连接数据库的代码：

Startup.cs：

public void ConfigureServices(IServiceCollection services)
{
    services.AddDbContext<postgresContext>(options =>
        options.UseNpgsql(SecretManagerAccessor.GetConnectionString())
    );
}

最后是SourceRepository：

private readonly postgresContext _db;
private readonly DbSet<Source> _source;

public SourceRepository(postgresContext db)
{
    _db = db;
    _source = db.Set<Source>();
}

public IEnumerable<Source> GetAll()
{
    return _source;
}

我使用此代码简化了测试，但仍然存在相同的问题：

        //GET : api/MyController
[HttpGet]
public IActionResult Get()
{
    Console.WriteLine("Get route called");
    try
    {
        _context.Database.CanConnect();
    }
    catch (Exception e)
    {
        Console.WriteLine(e);
    }

    return Ok();
}

在创建实例时，可以使用flag

--addcloudsql实例

。Cloud Run将为您激活并配置云SQL代理

连接字符串应类似于此字符串

“服务器=/cloudsql/您的项目id:us-central1:实例名称；Uid=aspnetuser；Pwd=；数据库=投票”

你可以看一下

---

还有一个repo展示了如何在云上构建C#应用程序，并使用Postgres运行

使用sqlservermanagementstudio，看看是否可以连接到数据库？检查登录窗口以查看是否使用了windows凭据或用户名/密码。大多数情况下，您使用的是Windows凭据。因此，连接字符串没有用户名/密码，而是使用integratedsecurity=True。如果使用的是标准端口号1433，则不需要端口号。在登录窗口中，连接字符串应包括服务器IP和实例like。对于SSMS，这似乎只是一个连接错误。请包括更多细节。你的博士后跑哪？您如何连接它（通过公共IP或VPC）？我的Postgres运行在谷歌云SQL上（两者都在同一个项目中），它通过身份验证连接到公共IP。我不能在我的计算机上运行它，因为项目使用docker，我的公司阻止我使用它

A 2020-08-26T13:58:49.877242Z An error occurred using the connection to database 'MyDb' on server 'tcp://xx.xx.xxx.xxx:5432'. 
A 2020-08-26T13:58:49.877242Z System.InvalidOperationException: An exception has been raised that is likely due to a transient failure. 
A 2020-08-26T13:58:49.877286Z  ---> Npgsql.NpgsqlException (0x80004005): Exception while connecting 
A 2020-08-26T13:58:49.877295Z  ---> System.TimeoutException: Timeout during connection attempt 
A 2020-08-26T13:58:49.877485Z    at Npgsql.NpgsqlConnector.Connect(NpgsqlTimeout timeout) 
A 2020-08-26T13:58:49.877514Z    at Npgsql.NpgsqlConnector.Connect(NpgsqlTimeout timeout) 
A 2020-08-26T13:58:49.877528Z    at Npgsql.NpgsqlConnector.RawOpen(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) 
A 2020-08-26T13:58:49.877540Z    at Npgsql.NpgsqlConnector.Open(NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) 
A 2020-08-26T13:58:49.877553Z    at Npgsql.ConnectorPool.AllocateLong(NpgsqlConnection conn, NpgsqlTimeout timeout, Boolean async, CancellationToken cancellationToken) 
A 2020-08-26T13:58:49.878103Z    at Npgsql.NpgsqlConnection.<>c__DisplayClass32_0.<<Open>g__OpenLong|0>d.MoveNext() 
A 2020-08-26T13:58:49.878128Z --- End of stack trace from previous location where exception was thrown --- 
A 2020-08-26T13:58:49.878136Z    at Npgsql.NpgsqlConnection.Open() 
A 2020-08-26T13:58:49.878145Z    at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected) 
A 2020-08-26T13:58:49.878152Z    at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected) 
A 2020-08-26T13:58:49.878161Z    at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReader(RelationalCommandParameterObject parameterObject) 
A 2020-08-26T13:58:49.878170Z    at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.InitializeReader(DbContext _, Boolean result) 
A 2020-08-26T13:58:49.878180Z    at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.NpgsqlExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded) 
A 2020-08-26T13:58:49.878188Z    --- End of inner exception stack trace --- 
A 2020-08-26T13:58:49.878197Z    at Npgsql.EntityFrameworkCore.PostgreSQL.Storage.Internal.NpgsqlExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded) 
A 2020-08-26T13:58:49.878203Z    at Microsoft.EntityFrameworkCore.Query.Internal.QueryingEnumerable`1.Enumerator.MoveNext() 
A 2020-08-26T13:58:49.878211Z    at MyProject.Controllers.MyController.Post(Body body) in /app/Controllers/MyController.cs:line 62 

        //GET : api/MyController
[HttpGet]
public IActionResult Get()
{
    Console.WriteLine("Get route called");
    try
    {
        _context.Database.CanConnect();
    }
    catch (Exception e)
    {
        Console.WriteLine(e);
    }

    return Ok();
}