Containerize ASP.NET Core API with src-test directory layout-CodePudding

I need to containerize a ASP.NET Core 6.0 Web API using Docker. The project can be found in this GitHub Repo of mine.

The project has the following structure:

───PlaygroundApiDockerized
    │
    ├───src
    │   ├───Playground.API
    |   |   ├───Dockerfile
    |   |   └───Playground.API.csproj
    |   |   
    │   └───Playground.Core
    |       └───Playground.Core.csproj
    │   
    ├───test
    │   ├───Playground.Tests
    │       └───Playground.Tests.csproj
    │
    ├───Playground.sln
    └───docker-compose.yml

The API project has a dependancy on a simple C# class library called Playground.Core and has a Dockerfile.

The content of the Dockerfile:

FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /src
COPY ["src/Playground.API/Playground.API.csproj", "Playground.API/"]
COPY ["src/Playground.Core/Playground.Core.csproj", "Playground.Core/"]
RUN dotnet restore "src/Playground.API/Playground.API.csproj"
COPY . .
WORKDIR "/src/Playground.API"
RUN dotnet build "Playground.API.csproj" -c Release -o /app/build

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

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

The docker-compose file looks like this:

version: '3.7'

services:
  playground-api:
    build:
      context: ./
      dockerfile: src/Playground.API/Dockerfile
    restart: always
    ports:
      - "7987:80"

My expectation is,when the docker-compose up command is exectuted in the solution root directory, the API is started.

But the command results in the following error below.

I understand that the current working directory where the command is executed is the context directory specified in the docker-compose.yml. In my example, the context is the solution root. I simply can't figure out how to specify the paths in the Dockerfile. Does anyone know?

Creating network "playgroundapidockerized_default" with the default driver
Building playground-api
[ ] Building 2.2s (11/18)
 => [internal] load build definition from Dockerfile                                                               0.0s
 => => transferring dockerfile: 720B                                                                               0.0s
 => [internal] load .dockerignore                                                                                  0.0s
 => => transferring context: 2B                                                                                    0.0s
 => [internal] load metadata for mcr.microsoft.com/dotnet/sdk:6.0                                                  0.8s
 => [internal] load metadata for mcr.microsoft.com/dotnet/aspnet:6.0                                               0.0s
 => [internal] load build context                                                                                  0.3s
 => => transferring context: 13.35MB                                                                               0.2s
 => [base 1/2] FROM mcr.microsoft.com/dotnet/aspnet:6.0                                                            0.0s
 => [build 1/8] FROM mcr.microsoft.com/dotnet/sdk:6.0@sha256:fde93347d1cc74a03f1804f113ce85add00c6f0af15881181165  0.0s
 => CACHED [build 2/8] WORKDIR /src                                                                                0.0s
 => [build 3/8] COPY [src/Playground.API/Playground.API.csproj, Playground.API/]                                   0.1s
 => [build 4/8] COPY [src/Playground.Core/Playground.Core.csproj, Playground.Core/]                                0.0s
 => ERROR [build 5/8] RUN dotnet restore "src/Playground.API/Playground.API.csproj"                                0.9s
------
 > [build 5/8] RUN dotnet restore "src/Playground.API/Playground.API.csproj":
#13 0.814 MSBUILD : error MSB1009: Project file does not exist.
#13 0.814 Switch: src/Playground.API/Playground.API.csproj
------
executor failed running [/bin/sh -c dotnet restore "src/Playground.API/Playground.API.csproj"]: exit code: 1
ERROR: Service 'playground-api' failed to build : Build failed

CodePudding user response：

When you copy the project files, your current directory in the image is /src and you copy it to Playground.API/ so the project file ends up having the absolute path /src/Playground.API/Playground.API.csproj.

When you then run dotnet restore, you use a relative path src/Playground.API/Playground.API.csproj. So it looks for /src/src/Playground.API/Playground.API.csproj which doesn't exist.

Later when you copy all the files with COPY . . you get the directory structure from the host, so now your files become /src/src/Playground.API/Playground.API.csproj etc. At this point you have 2 copies of your project files. One in /src/Playground.API and one in /src/src/Playground.API.

I think the best thing to do is keep the host directory structure under the working directory, i.e. /src/src/.... I'd rename the working directory to something other than /src to avoid confusion. Something like this

FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /app
COPY ["src/Playground.API/Playground.API.csproj", "src/Playground.API/"]
COPY ["src/Playground.Core/Playground.Core.csproj", "src/Playground.Core/"]
RUN dotnet restore "src/Playground.API/Playground.API.csproj"
COPY . .
WORKDIR "/app/src/Playground.API"
RUN dotnet build "Playground.API.csproj" -c Release -o /app/build

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

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