Code review comment for lp://staging/~boyang-niu/maas/enable_custom_images

We've been trying to commission or install a node with a custom image, but we didn't succeed with either. :( We managed to upload custom images, but a node configured to commission with it wouldn't netboot, and we were unable to select a custom install image for deployment.

Unless you have anything in there that's likely to fix both these problems, we're thinking we're better off re-doing what you wrote here, in smaller steps. It will help us see any things that we may have missed, and get us gradually towards the point where we can address the problem of getting uploaded images onto the cluster servers. It may involve a long-planned python rewrite of the download scripts, too.