nginx alpine docker fails without previous ls?

nginx permissions docker ls alpine

Moving my answer from the comments.

Such weirdness is usually related to a Docker storage driver.

There are usually several available Docker storage drivers available on most OSes:

AUFS (available and default in Ubuntu, Boot2Docker, and also available in Debian testing) - while, AFAIK, it was historically the first FS driver in Docker, AUFS is not part of mainline Linux kernel, so it is not widely adopted.
OverlayFS - mainline Linux kernel closest alternative to AUFS
Device Mapper - the slowest, but the most portable Docker storage driver
etc...

Here is a nice picture comparing different storage drivers from the link posted above.

CodeHunter