Docker seems to be running with the wrong volume

Question

I have a web project that is written on the top of the ASP.NET Core 3.1 framework. I want to run the project in a docker container on a Linux virtual box.

I create the following docker-compose.yml file

version: '3.4'

services:
  myproject:
    image: ${DOCKER_REGISTRY-}myproject
    build:
      context: .
      dockerfile: myproject/Dockerfile
    volumes:
      - storage:/storage
      - ${APPDATA}/Microsoft/UserSecrets:/root/.microsoft/usersecrets:ro
      - ${APPDATA}/ASP.NET/Https:/root/.aspnet/https:ro
    environment:
      - ASPNETCORE_ENVIRONMENT=Development
      - ASPNETCORE_URLS=https://+:443;http://+:80
    ports:
      - 51736:80
      - 44344:443
volumes:
  storage:

When I execute docker-compose up --build

I get the following output

Successfully built b084cb989f05
Successfully tagged myproject:latest
Starting myproject_myproject_1 ... done
Attaching to myproject_myproject_1
myproject_1  | Unhandled exception. System.IO.DirectoryNotFoundException: /app/Storage/
myproject_1  |    at Microsoft.Extensions.FileProviders.PhysicalFileProvider..ctor(String root, ExclusionFilters filters)
myproject_1  |    at Microsoft.Extensions.FileProviders.PhysicalFileProvider..ctor(String root)

From the logs above the app is looking for /app/Storage/ path to initialize the PhysicalFileProvider. I am not sure where that is coming from. According to my docker-compose.yml file, the storage volume should me /storage not /app/Storage/.

At some point, I had storage:/app/Storage in my docker-compose.yml file but it is no longer there. What could be causing the image to attach the wrong volume/storage folder?

Updated

Here is the content of the Dockerfile

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
WORKDIR /src
COPY ["myproject/myproject.csproj", "myproject/"]
RUN dotnet restore "myproject/myproject.csproj"
COPY . .
WORKDIR "/src/myproject"
RUN dotnet build "myproject.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "myproject.csproj" -c Release -o /app/publish

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

I tried the following command to delete everything

docker-compose down -v --rmi all --remove-orphans
docker-compose build --no-cache

However, I am still getting the same result. How can I correctly mount the /storage folder with the image?

Answer 1

The message is not related to docker-compose I think.

Something in the application is telling it to look at that folder. It's correct that the folder doesn't exist because the docker-compose doesn't create it.

Check the code or config in the ASP.NET application itself that provides this path. Or the docker command that runs the dotnet process als, or the environment variables set in the dockerfile.

Update:

Looking at your dockerfile, I'm guessing the app is looking for storage only not /storage (relative path not absolute path), and that's why you are getting the extra /app in the beginning (from the workdir).