title: GitHub Action Error: Docker pull failed with exit code 1
body: <p>I'm trying to run my <code>npm</code> build inside the docker container using our private docker image with GitHub actions.</p>
  <p>My Workflow <code>yaml</code> file as follows,</p>
  <pre class="lang-yaml prettyprint-override"><code>jobs:
    build:
      runs-on: Linux-self-hosted  # This is our self hosted linux runner system.
      container:
        image: ubuntu-20.04-lts:latest  # This is our private docker image.
  
      steps:
      - name: Checkout Repository
        uses: actions/checkout@v2
        
      - name: Npm Build
        run: npm install
  
      - name: Build Package
        run: vsce package
  </code></pre>
  <p><strong>GitHub Action Error:-</strong></p>
  <blockquote>
  <p>Starting job container   /usr/bin/docker pull ubuntu-20.04-lts:latest
  Error response from daemon: pull access denied for ubuntu-20.04-lts,
  repository does not exist or may require 'docker login': denied:
  requested access to the resource is denied   Warning: Docker pull
  failed with exit code 1, back off 4.74 seconds before retry.<br />
  /usr/bin/docker pull ubuntu-20.04-lts:latest   Error response from
  daemon: pull access denied for ubuntu-20.04-lts, repository does not
  exist or may require 'docker login': denied: requested access to the
  resource is denied   Warning: Docker pull failed with exit code 1,
  back off 9.535 seconds before retry.   /usr/bin/docker pull
  ubuntu-20.04-lts:latest   Error response from daemon: pull access
  denied for ubuntu-20.04-lts, repository does not exist or may require
  'docker login': denied: requested access to the resource is denied<br />
  Error: Docker pull failed with exit code 1</p>
  </blockquote>
  <p>i have this <code>ubuntu-20.04-lts:latest</code> private docker image on my host system locally. Still it fails with above error during action build.</p>
  <p>It looks trying to connect docker hub. How do i fix this to use our local private image?</p>