It is possible that network files do not exist, especially in the case
of `--net=host` where a host OS (like CoreOS) does not use certain
standard network files. This patch verifies that the source file of a
network mount point exists before adding it to the list of mount points
for bind mounting from the container's metadata directory.
Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
Upstream-commit: ed68486f687ce9d5963d7250f70dc66c9f14cd63
Component: engine
21d501b5ba