Dockerhub will introduce rate limiting in November, and a lot of E2E tests
are relying on the busybox image. It could potentially become an issue
causing jobs to fail because of this.
Ideally, we'd have the busybox image mirrored on gcr.io, but that could take
some time. Until then, we can just have the Image Builder mirror the image
for us in the staging registry and use that for tests until this issue is
solved. The busybox image should NOT be promoted out of staging.
During the sig-testing meeting, it was decided that we should do the same
for the other images are hosted on dockerhub.
Two different versions of httpd and nginx have to be built, and thus, the have
different folders. An ALIAS file was added to httpd-new and nginx-new in order
to keep the same image name.
