title: Github actions runner environment doesn't build for arm images
body: <p>I get this error on my github build:</p>
  <blockquote>
  <p>The requested image's platform (linux/arm/v7) does not match the detected host platform (linux/amd64) and no specific platform was requested</p>
  </blockquote>
  <p>The runner environment I'm using is the ubuntu:latest and my container uses arm32v7/node base image.</p>
  <p>Here's my Dockerfile:</p>
  <pre><code>FROM arm32v7/node AS appbuild
  WORKDIR /app
  COPY package.json ./
  COPY src/ ./src
  RUN npm install
  
  FROM appbuild as release
  ENTRYPOINT [&quot;npm&quot;, &quot;start&quot;]
  </code></pre>
  <p>And here's my deployment to github yaml:</p>
  <pre><code>jobs:
    docker:
      runs-on: ubuntu-latest
  </code></pre>
  <p>The jobs are ran inside a ubuntu runner environment. I suspect the arm version of the node image I'm using is unable to run in that environment, is that correct?</p>
  <p>Edit:</p>
  <pre><code>  - name: Build controller image
      if: steps.changed-files-plantcontroller.outputs.any_changed == 'true'
      run: &gt;
        docker build -t ${{ env.image_name_controller }} ${{ env.context }}
      env:
        context: ./controller
  </code></pre>