aspnetcore: [.NET 8] ASP.NET Core Web API Server is Not Accessible in Docker

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

Hi,

I created a clean, default ASP.NET Core Web API project. The project name is “WebApplication4”. I didn’t change a thing in the project. So, everything is intact. I ran this project in release mode & docker. No problem until this point. I closed the docker container and tried to rerun the docker image using command line. My command was docker run -it -p 8080:8080 webapplication4:latest . I tried to access https://localhost:8080/swagger and https://localhost:8080/swagger/index.html. However, none of them is opening and I got an error like this ERR_SSL_PROTOCOL_ERROR.

To fix this, I cleaned all SSL protocols defined before and redefined it by trusting. It did not help. No change in the behaviour.

-> dotnet dev-certs https --clean -> dotnet dev-certs https

This behavior did not happen before until I updated my visual studio for .net 8.

The docker file is:

#See https://aka.ms/customizecontainer to learn how to customize your debug container and how Visual Studio uses this Dockerfile to build your images for faster debugging.

FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
USER app
WORKDIR /app
EXPOSE 8080
EXPOSE 8081

FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
ARG BUILD_CONFIGURATION=Release
WORKDIR /src
COPY ["WebApplication4/WebApplication4.csproj", "WebApplication4/"]
RUN dotnet restore "./WebApplication4/./WebApplication4.csproj"
COPY . .
WORKDIR "/src/WebApplication4"
RUN dotnet build "./WebApplication4.csproj" -c $BUILD_CONFIGURATION -o /app/build

FROM build AS publish
ARG BUILD_CONFIGURATION=Release
RUN dotnet publish "./WebApplication4.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "WebApplication4.dll"]

The launchSettings.json file is:

{
  "profiles": {
    "http": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "dotnetRunMessages": true,
      "applicationUrl": "http://localhost:5117"
    },
    "https": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      },
      "dotnetRunMessages": true,
      "applicationUrl": "https://localhost:7099;http://localhost:5117"
    },
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "Docker": {
      "commandName": "Docker",
      "launchBrowser": true,
      "launchUrl": "{Scheme}://{ServiceHost}:{ServicePort}/swagger",
      "environmentVariables": {
        "ASPNETCORE_HTTPS_PORTS": "8081",
        "ASPNETCORE_HTTP_PORTS": "8080"
      },
      "publishAllPorts": true,
      "useSSL": true
    }
  },
  "$schema": "http://json.schemastore.org/launchsettings.json",
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:15057",
      "sslPort": 44358
    }
  }
}

Expected Behavior

https://localhost:8080/swagger url should have been accessed successfully after running the docker from command line.

Steps To Reproduce

-> Open Visual Studio 17.8.0. -> Create a ASP.NET Core Web API with default settings. -> Run once in release mode in docker. -> Close the container. -> Rerun the docker image via command line terminal using docker run -it -p 8080:8080 webapplication4:latest. -> The server is not accessible via https://localhost:8080/swagger.

Exceptions (if any)

No response

.NET Version

8.0.100

Anything else?

Visual Studio 17.8.0 .NET 8.0.100