无法运行 dockerized .NET Core (3.1) API

Question

Dockerfile

# syntax=docker/dockerfile:1
FROM mcr.microsoft.com/dotnet/sdk:3.1 AS build-env
WORKDIR /app
# Copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore
# Build
RUN dotnet publish -c Release -o out
# Build runtime image
FROM mcr.microsoft.com/dotnet/aspnet:3.1
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "myapp.dll"]

第一次构建它时，我出现了以下错误：

错误CS5001：程序不包含适用于入口点的静态"Main"方法

我通过添加解决了这个问题

<OutputType>Library</OutputType>

到我的.csproj，然后我可以构建它。

此时，当尝试使用运行它时

docker run -p 8082:8080 --rm dockerized-app:dev

Docker抛出此错误：

在"/app/"中找不到执行应用程序所需的库"libhostpolicy.so"。

在互联网上寻找解决方案时，我发现添加可以解决问题

<GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>

到.csproj，我做了，再次构建，当运行时，我得到了这个我无法解决的错误：

在程序集"myapp，Version=1.0.0.0，Culture=neutral，PublicKeyToken=null"中找不到入口点。

编辑：添加API的实际代码。

Controller.cs:

[ApiController]
[Route("api/[controller]")]
public class MyAppController : ControllerBase
{
[EnableCors("AllowOrigin")]
[HttpGet]
public string GetText(Request request)
{
return request.text;
}
}

程序.cs:

public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
});

Startup.cs:

public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.AddCors(options =>
{
options.AddPolicy("AllowAllHeaders",
builder =>
{
builder.AllowAnyOrigin()
.AllowAnyHeader()
.AllowAnyMethod();
});
});
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseCors(builder =>
{
builder
.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader();
});
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}

launchSettings.json:

{
"$schema": "http://json.schemastore.org/launchsettings.json",
"iisSettings": {
"windowsAuthentication": false,
"anonymousAuthentication": true,
"iisExpress": {
"applicationUrl": "http://localhost:58726",
"sslPort": 0
}
},
"profiles": {
"IIS Express": {
"commandName": "IISExpress",
"launchBrowser": true,
"launchUrl": "myapp",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
},
"MyApp": {
"commandName": "Project",
"launchUrl": "myapp",
"applicationUrl": "http://localhost:5000",
"environmentVariables": {
"ASPNETCORE_ENVIRONMENT": "Development"
}
}
}
}

myapp.csproj(带有我之前提到的更改(：

<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp3.1</TargetFramework>
<OutputType>Library</OutputType>
<GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
</PropertyGroup>

<ItemGroup>
<None Remove="Newtonsoft.Json" />
<None Remove="Models" />
</ItemGroup>
<ItemGroup>
<PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
</ItemGroup>
<ItemGroup>
<Folder Include="Models" />
</ItemGroup>
</Project>

而且，万一有人问，它在本地工作，它会启动并等待收到请求。

Answer 1

您只能将.csproj文件复制到映像中。您错过了复制其余文件的步骤。

# syntax=docker/dockerfile:1
FROM mcr.microsoft.com/dotnet/sdk:3.1 AS build-env
WORKDIR /app
# Copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore
# vvvv   This is missing
COPY . .
# Build
RUN dotnet publish -c Release -o out
# Build runtime image
FROM mcr.microsoft.com/dotnet/aspnet:3.1
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "myapp.dll"]