title: Dockerfile with copy command and relative path
body: <p>Have same way to use copy command with relative path in dockerfile? Im trying to use:</p>
  
  <pre><code>COPY ./../folder/*.csproj ./
  </code></pre>
  
  <p>OBS.: My struct folder (Im running the dockerfile on project-test and another files is in project-console folder) is:</p>
  
  <p>|- project-console</p>
  
  <p>|- project-test</p>
  
  <p>And Im receive the follow error:</p>
  
  <p>ERROR: service 'app' failed to build: COPY failed: no source files were specified.</p>
  
  <p><strong><em>My purpose is</em></strong> have two projects in the same docker. I have a dotnet core console and another with unity test (NUnity), Im trying run the unity test in docker.</p>
  
  <p><strong><em>UPDATE</em></strong></p>
  
  <p>Is possible to use Multi-stage: <a href="https://docs.docker.com/develop/develop-images/multistage-build/" rel="noreferrer">https://docs.docker.com/develop/develop-images/multistage-build/</a></p>
  
  <p>Or using docker-compose with build: <a href="https://docs.docker.com/engine/reference/commandline/build/" rel="noreferrer">https://docs.docker.com/engine/reference/commandline/build/</a></p>
  
  <p>Like:</p>
  
  <pre><code>services: 
  
  worker:
      build:
        context: ./workers
        dockerfile: Dockerfile
  </code></pre>