Images/css/js files not available on docker container - asp.net

Question

I'm learning microservice concept and using Docker for these purposes.
I have 3 containers:
mssqlserver - my database
asp-net-core:2.0 - for my microservice (only 1 at the moment)
asp-net-core:2.0 - MVC
Connection exists between these so this isn't a cause of the problem.
MVC contains wwwroot directory where images (banners etc.), css and .js files are placed. I've checked they are on my docker container (ran /bin/bash on container and checked).
But somehow my .cshtml files can't see these files.
Dockerfile for MVC project:
FROM microsoft/aspnetcore-build:2.0 AS build-env
WORKDIR /app
# copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore
# copy everything else and build
COPY . ./
RUN dotnet publish -c Release -o out
# build runtime image
FROM microsoft/aspnetcore:2.0
WORKDIR /app
COPY --from=build-env /app/out .
EXPOSE 80/tcp
ENTRYPOINT ["dotnet", "MVC.dll"]
docker-compose:
version: "3.2"
networks:
frontend:
backend:
services:
webmvc:
build:
context: .\src\Web\MVC
dockerfile: Dockerfile
environment:
- ASPNETCORE_ENVIRONMENT=Development
- CatalogUrl=http://catalog
container_name: webshop
ports:
- "5500:80"
networks:
- frontend
depends_on:
- catalog
catalog:
build:
context: .\src\Services\ProductCatalogApi
dockerfile: Dockerfile
image: microservices-v1.0.0
environment:
- DatabaseServer=mssqlserver
- DatabaseName=CatalogDb
- DatabaseUser=sa
- DatabaseUserPassword=ProductApi(!)
container_name: catalogapi
ports:
- "5000:80"
networks:
- backend
- frontend
depends_on:
- mssqlserver
mssqlserver:
image: "microsoft/mssql-server-linux:latest"
ports:
- "2200:1433"
container_name: mssqlcontainer
environment:
- ACCEPT_EULA=Y
- SA_PASSWORD=ProductApi(!)
networks:
- backend
Example use of image (in Index.cshtml):
<img src="~/images/banner.jpg" alt="ASP.NET" class="img-responsive" />
I've tried differenet combination of path to image like:
<img src="wwwroot/images/banner.jpg" alt="ASP.NET" class="img-responsive" />
<img src="~/app/wwwroot/images/banner.jpg" alt="ASP.NET" class="img-responsive" />
<img src="app/wwwroot/images/banner.jpg" alt="ASP.NET" class="img-responsive" />
None of these worked.

Answer 1

Most likely you failed to enable the static files middleware in your ASP.NET Core project. In Startup.Configure, you need the line:
app.UseStaticFiles();
That will serve up wwwroot, by default, as the document root of your site, so you would then reference in static files under that via:
<img src="~/images/banner.jpg" />
Which would correspond to the file at wwwroot/images/banner.jpg.