ASP.NET Core 应用程序不会在容器中启动

Question

I have an ASP.NET Core app which I'm trying to deploy in a docker container. I have a different container for development, which works fine, but I can't get a production version to work.

The dockerfile (see below) I have is based on the one from here , the application builds just fine, but won't run. I get the following error:

web_1  |   It was not possible to find any installed .NET Core SDKs
web_1  |   Did you mean to run .NET Core SDK commands? Install a .NET Core SDK from:
web_1  |       https://aka.ms/dotnet-download

After which the container terminates with code 145.

Dockerfile.prod:

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
WORKDIR /app

RUN curl -sL https://deb.nodesource.com/setup_13.x |  bash -
RUN apt-get install -y nodejs unzip libc6-dev libgdiplus

# Copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore

# Copy everything else and build
ADD . ./
RUN dotnet publish -c Release -o out

# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
RUN mkdir -p /openld-data/fixture-images
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "openld.dll"]

docker-compose.yml

version: "3.3"

services:
  web:
    build:
      context: .
      dockerfile: Dockerfile.prod
    ports:
      - "5000:5000"
    depends_on:
      - db
    volumes:
      - ./:/app
      - openld-data:/openld-data
  db:
    image: "postgres:12.1"
    environment:
        POSTGRES_DB:
        POSTGRES_USER:
        POSTGRES_PASSWORD:
    ports:
      - "5432:5432"
    volumes:
      - postgres-data:/var/lib/postgresql/data
volumes:
  postgres-data:
  openld-data:

I don't know why it isn't working, the sample ASP.NET containers do something very similar and work just fine. If anyone knows what causes this, any help would be greatly appreciated.

Answer 1

Your problem seems to be this line:

 volumes:
  - ./:/app

It maps your local current drive to containers /app . So instead the executable you've built in container, you're using the one built on your machine. Delete the - ./:/app and give it a try.