docker could not find a file from wwwroot

Question

It is my first attempt to run a docker image in my asp.net core 5.0 application. I have added the following configuration in the docker file.

FROM mcr.microsoft.com/dotnet/aspnet:5.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/sdk:5.0 AS build
WORKDIR /src
COPY ["Shopping.Client/Shopping.Client.csproj", "Shopping.Client/"]
RUN dotnet restore "Shopping.Client/Shopping.Client.csproj"
COPY . .
WORKDIR "/src/Shopping.Client"
RUN dotnet build "Shopping.Client.csproj" -c Release -o /app/build

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

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

I am trying to access the files that are in my wwwroot folder, using the following code:

private async Task<T> ReadAsync<T>(string filePath)
{

    using FileStream stream = File.OpenRead(filePath);
    return await JsonSerializer.DeserializeAsync<T>(stream);
}

public async Task<List<Product>> GetProducts()
{
    var filePath = System.IO.Path.Combine(_env.ContentRootPath, @"wwwroot\Db\product.json");
    return await ReadAsync<List<Product>>(filePath);
}

When I run the application and trying to access the files in wwwroot I am getting the error as:

An unhandled exception has occurred while executing the request.
System.IO.FileNotFoundException: Could not find file '/app/wwwroot\Db\product.json'. File name: '/app/wwwroot\Db\product.json'

Should I include anything special in the docker file to copy the wwwroot folder or do I need to add the file path considering the path in the docker image?

Answer 1

It appears that you are using Linux containers and using Windows file path conventions. Path.Combine does support this, but it needs some help.

/app/wwwroot\Db\product.json

Try wwwroot/Db/product.json

If this is your issue, you may wish to examine the overloads for Path.Combine as the Combine method has additional overloads that accept additional parameters

1. public static string Combine(string path1, string path2, string path3)
2. public static string Combine(string path1, string path2, string path3, string path4)
3. public static string Combine(params string[] paths)

Your code: Path.Combine(_env.ContentRootPath, @"wwwroot\Db\product.json");

Would then become something like: Path.Combine(basePath, "wwwroot", "Db", "product.json");