context or workdir for docker-compose : <p>I'm learning docker</p>

<p>I need to specify the working directory for a docker image, I think that'll be something like this:</p>

<pre><code>version: '2'
services:
  test:
    build:
      context: ./dir
</code></pre>

<p>Now I want to make the image <code>python:onbuild</code> to run on the <code>./dir</code>, but I dont want to create any <code>Dockerfile</code> inside the <code>./dir</code>.</p>

<p>The <code>docker-compose</code> manual says nothing about that.</p>

<p>Is it possible? How to do that?</p>
