EOF error when deploying a non-existent tag

[ejholmes]

This error is somewhat specific to us. If you have a repository that has a lot of tags in it (e.g. you tag every image with the git sha), when you try to deploy an image using a tag that doesn't exist, you'll see it stall for a minute or two and fail with:

$ emp deploy remind101/acme-inc:nonexistenttag
Pulling repository remind101/acme-inc
error: unexpected EOF

This happens because the behavior of the docker client is to first try to find the tag in the v2 registry, then fallback to pulling all tags using the v1 registry API. Because there's so many tags, this times out and returns the EOF error.

This technically isn't an Empire bug, but tracking it here in case someone else runs into it.

See also distribution/distribution#797

[ejholmes]

FYI. I'm not able to reproduce this on Docker 1.8.1.