Integration tests with docker compose

Docker Engine Compose
1

I have a simple dotnet test that just fails during running:

        [Fact]
        public void Test1()
        {
            throw new System.Exception("test");
        }

that I want to launch via docker-compose.
NOTE: It’s a synthetic case that just asks about proper configuration to run custom script (bash/cmd?) from docker-compose side. In real example I want to add an integration test that will include communicating logic with different containers as in my main application.

Docker file:

        FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
        WORKDIR /src
        EXPOSE 80
        EXPOSE 443
        # restore
        COPY ["MyTests/MyTests.csproj", "MyTests/"]
        RUN dotnet restore "MyTests/MyTests.csproj"
        # build
        COPY . .
        WORKDIR "/src/MyTests"
        RUN dotnet build "MyTests.csproj" -c Release -o /app/build

        ENTRYPOINT ["/bin/bash"]

. This files configuration works well, when I run this from my local machine:

        %SomePath%\Demo>docker build -f MyTests/Dockerfile  -t mytest .
        [+] Building 0.3s (12/12) FINISHED
         => [internal] load build definition from Dockerfile
         => => transferring dockerfile: 32B
         => [internal] load .dockerignore
         => => transferring context: 35B
         => [internal] load metadata for mcr.microsoft.com/dotnet/sdk:6.0
         => [1/7] FROM mcr.microsoft.com/dotnet/sdk:6.0
         => [internal] load build context
         => => transferring context: 2.00kB
         => CACHED [2/7] WORKDIR /src 
         => CACHED [3/7] COPY [MyTests/MyTests.csproj, MyTests/] 
         => CACHED [4/7] RUN dotnet restore "MyTests/MyTests.csproj"
         => CACHED [5/7] COPY . .
         => CACHED [6/7] WORKDIR /src/MyTests
         => CACHED [7/7] RUN dotnet build "MyTests.csproj" -c Release -o /app/build
         => exporting to image
         => => exporting layers
         => => writing image sha256:9c...
         => => naming to docker.io/library/mytest

        %SomePath%\Demo>docker run -it mytest
        root@999afef78716:/src/MyTests# ls
        MyTests.csproj  ApiTests.cs  Properties  obj

You may see, that now I’m able to use bash scripts, so I “can” run something like: “dotnet test” to launch tests I have.
But when I do similar steps via docker-compose:

        version: '3.4'

        services:
          xunitwithdocker:
            image: ${DOCKER_REGISTRY-}xunitwithdocker
            build:
              context: .
              dockerfile: XUnitWithDocker/Dockerfile
            command: ["echo", "test!"]

The container throws:

==> /dev/null <==
tail: cannot open 'echo' for reading: No such file or directory
tail: cannot open 'test!' for reading: No such file or directory

It’s a bit unclear where “tail” has come from?
My colleague has created a SO question about it here: bash - Docker Compose. Call a custom script - Stack Overflow

Can someone help with this?

2

It appears to be from the images entrypoint script. Share your Dockerfile and we will see that the ENTRYPOINT instruction either uses tail or points to a script that does use tail and then hands over to $@

3

I already did this, see above.

4

Indeed, you shared it. I missed it.

I would have expected to see an entrypoint script or tail itself.

You might want to change your ENTRYPOINT to ["/bin/bash","-c"].
Though, it remains a mystery why the tail command was involved at all.

5

still the same, I can share a small repro project if it would work

6

Apparently the tail part is added by visual studio that I used to build and run my application, I found it in the logs:

    docker-compose  -f "%PATH%\docker-compose.yml" -f "%PATH%\docker-compose.override.yml" -f "%PATH%\obj\Docker\docker-compose.vs.debug.g.yml" -p dockercompose14997374556887134345 --ansi never --profile "*" config
    name: dockercompose14997374556887134345
    services:
      consoleappdocker:
        build:
          context: %PATH%
          dockerfile: ConsoleAppDocker/Dockerfile
          labels:
            com.microsoft.created-by: visual-studio
            com.microsoft.visual-studio.project-name: ConsoleAppDocker
        command:
        - /bin/bash
        - -c
        - echo test
        container_name: consoletest
        entrypoint:
        - tail
        - -f
        - /dev/null
        environment:
    ..
        image: consoleappdocker:dev
        labels:
    ..
        networks:
          default: null
        tty: true
        volumes:
    ..
    networks:
      default:
        name: dockercompose14997374556887134345_default
    docker-compose  -f "%PATH%\docker-compose.yml" -f "%PATH%\docker-compose.override.yml" -f "%PATH%\obj\Docker\docker-compose.vs.debug.g.yml" -p dockercompose14997374556887134345 --ansi never build

quite unexpected case, now I’m thinking about how can I disable this…