Parallel image pulls when setting up the environment



If you have multiple container images specified in docker 2.0, it appears they are all pulled down serially during the spin up environment phase. It adds a fair bit of time for each extra image.

Would it be possible to either:

  1. pull these down in parallel?
  2. pull the primary container, and then continue with the steps while the others are booted?
  3. pull all images in parallel, AND continue to the next steps after the primary image is booted.

I’m guessing option 1 and 3 are bad for estimating and managing concurrent bandwidth per build, but 2 would be really great. I already am using dockerize at the point where the other images are required, so might as well do tasks on the first image until that point.

closed #2