Installing rsync, gulp on gitlab-runner docket

Hello -
We are using Gitlab-runner on locally hosted Ubuntu LTS 16.04 host with docker.

The runner image is missing rsync and gulp packages. The packages are installed on the Ubuntu but not visible to docker. Hence following install commands are executed with every pipeline job.

  • ‘which gulp || ( apt-get update -y && npm install -g gulp )’
  • ‘which rsync || ( apt-get update -y && apt-get install rsync )’

Why are the packages not getting saved and how can we fix this? Just for understanding, can someone please help me here? This is very new to me.

Thanks in advance.