Monthly Archives: April 2020

Docker – Severity Code Description Project File Line Suppression State Error DT1001 Service service has neither an image nor a build context specified. At least one must be provided. docker-compose C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Sdks\Microsoft.Docker.Sdk\build\Microsoft.VisualStudio.Docker.Compose.targets 204

Hi everyone,

I ran into the following error while using docker compose and visual studio:

Severity Code Description Project File Line Suppression State
Error DT1001 Service has neither an image nor a build context specified. At least one must be provided. docker-compose C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Sdks\Microsoft.Docker.Sdk\build\Microsoft.VisualStudio.Docker.Compose.targets 204

It took a bit of poking around to find as the error seemed a bit ambiguous, but luckily this turned out to be a simple mistake on my part. I’d renamed my service from “servicename” to “service_name” in docker-compose.yml. Unfortunately, I hadn’t noticed the visual studio had automatically added an entry to docker-compose.override.yml. Because I hadn’t updated this entry it couldn’t find an image for the non-existent service.

A simple error on my part, but hopefully it’s able to save you a bit of time!

Cheers,
Chris

Automapper protobuf datetime to timestamp c#

Hi everyone,

I ran into the following error tonight while attempting to use automapper to map a datetime field to a protobuf timestamp property:

automapper missing type map “DateTime -> Timestamp”

To fix it, add the following to your mapping profile:

CreateMap().ConvertUsing(x => x.ToTimestamp());

UPDATE:
I later hit a similar error parsing a different entity:

Type Map configuration:
Entity-> EntityDto
EntityService.Models.Entity-> EntityService.EntityDto

Destination Member:
CreatedAt

—> System.ArgumentException: Conversion from DateTime to Timestamp requires the DateTime kind to be Utc (Parameter ‘dateTime’)

Implementing the following map appears to have resolved it:

CreateMap().ConvertUsing(x => Timestamp.FromDateTime(DateTime.SpecifyKind(x, DateTimeKind.Utc)));

If you’re planning to go the other way (timestamp -> datetime) you may also need the following:

CreateMap().ConvertUsing(x => x.ToDateTime());

I’m currently using the following base class in my library:

public class BaseMappingProfile : Profile
{
public BaseMappingProfile()
{
CreateMap().ConvertUsing(x => Timestamp.FromDateTime(DateTime.SpecifyKind(x, DateTimeKind.Utc)));
CreateMap().ConvertUsing(x => x.ToDateTime());
}
}

Google didn’t seem to turn up a lot so I thought I’d post it here in case it helps someone out!

Http gRPC with .NET Core and Docker – Error starting gRPC call. System.Net.Http.HttpRequestException: An error occurred while sending the request. —> System.IO.IOException: The response ended prematurely.

Hi everyone,

I’ve been mucking around with gRPC today while using .NET Core and Docker. I have two Microservices in the setup, one server and one client. Because these services will only be communicating internally I intended to use HTTP instead of HTTPS. Unfortunately, I hit the following error while attempting to set this up:

Error starting gRPC call. System.Net.Http.HttpRequestException: An error occurred while sending the request. —> System.IO.IOException: The response ended prematurely.

According Microsoft’s eshoponcontainers documentation there are a few extra steps for getting this to work:

Using gRPC without TLS
gRPC works with HTTP/2 only. Usually when a client connects to a server, the connection is done using HTTP1.1 and promoted to HTTP/2 only if both, server and client, support HTTP/2. This promotion is performed using a protocol negotiation, usually implemented using ALPN protocol which requires TLS.

In order to get it to work you need to add the following to your server :

.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup()

.ConfigureKestrel(options =>
{
options.Listen(IPAddress.Any, 5001, listenOptions =>
{
listenOptions.Protocols = HttpProtocols.Http2;
});
});
});

You then need to explicitly allow HTTP/2 without TLS when creating the client:

AppContext.SetSwitch(“System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport”, true);
AppContext.SetSwitch(“System.Net.Http.SocketsHttpHandler.Http2Support”, true);

// The port number(5001) must match the port of the gRPC server.
var channel = GrpcChannel.ForAddress(endpoint, new GrpcChannelOptions { LoggerFactory = loggerFactory });
var client = new CatalogService.Catalog.CatalogClient(channel);

Note that the AppContext.SetSwitch statements need to appear before the client is created to work. There’s also a bit of an overview on the following page: https://github.com/dotnet-architecture/eShopOnContainers/wiki/gRPC

The following stackoverflow post also helped with the ordering issue: https://stackoverflow.com/a/58053460/522859